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src/backend/commands/tablecmds.c
24 428 строк
760 KB
Nathan Bossart
Check for USAGE privilege on the composite type in ALTER TABLE OF.
10 авг 2026, 16:37
10 авг 2026, 16:37
53ed5eb
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/*------------------------------------------------------------------------- * * tablecmds.c * Commands for creating and altering table structures and settings * * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * * * IDENTIFICATION * src/backend/commands/tablecmds.c * *------------------------------------------------------------------------- */ #include "postgres.h" #include "access/attmap.h" #include "access/genam.h" #include "access/gist.h" #include "access/heapam.h" #include "access/heapam_xlog.h" #include "access/multixact.h" #include "access/reloptions.h" #include "access/relscan.h" #include "access/sysattr.h" #include "access/tableam.h" #include "access/toast_compression.h" #include "access/tupconvert.h" #include "access/xact.h" #include "access/xlog.h" #include "access/xloginsert.h" #include "catalog/catalog.h" #include "catalog/heap.h" #include "catalog/index.h" #include "catalog/namespace.h" #include "catalog/objectaccess.h" #include "catalog/partition.h" #include "catalog/pg_am.h" #include "catalog/pg_attrdef.h" #include "catalog/pg_collation.h" #include "catalog/pg_constraint.h" #include "catalog/pg_depend.h" #include "catalog/pg_extension_d.h" #include "catalog/pg_foreign_table.h" #include "catalog/pg_inherits.h" #include "catalog/pg_largeobject.h" #include "catalog/pg_largeobject_metadata.h" #include "catalog/pg_namespace.h" #include "catalog/pg_opclass.h" #include "catalog/pg_policy.h" #include "catalog/pg_proc.h" #include "catalog/pg_publication_rel.h" #include "catalog/pg_rewrite.h" #include "catalog/pg_statistic_ext.h" #include "catalog/pg_tablespace.h" #include "catalog/pg_trigger.h" #include "catalog/pg_type.h" #include "catalog/storage.h" #include "catalog/storage_xlog.h" #include "catalog/toasting.h" #include "commands/comment.h" #include "commands/defrem.h" #include "commands/event_trigger.h" #include "commands/extension.h" #include "commands/repack.h" #include "commands/sequence.h" #include "commands/tablecmds.h" #include "commands/tablespace.h" #include "commands/trigger.h" #include "commands/typecmds.h" #include "commands/user.h" #include "commands/vacuum.h" #include "common/int.h" #include "executor/executor.h" #include "foreign/fdwapi.h" #include "foreign/foreign.h" #include "miscadmin.h" #include "nodes/makefuncs.h" #include "nodes/nodeFuncs.h" #include "nodes/parsenodes.h" #include "optimizer/optimizer.h" #include "parser/parse_coerce.h" #include "parser/parse_collate.h" #include "parser/parse_expr.h" #include "parser/parse_relation.h" #include "parser/parse_type.h" #include "parser/parse_utilcmd.h" #include "parser/parser.h" #include "partitioning/partbounds.h" #include "partitioning/partdesc.h" #include "pgstat.h" #include "rewrite/rewriteDefine.h" #include "rewrite/rewriteHandler.h" #include "rewrite/rewriteManip.h" #include "storage/bufmgr.h" #include "storage/lmgr.h" #include "storage/lock.h" #include "storage/predicate.h" #include "storage/smgr.h" #include "tcop/utility.h" #include "utils/acl.h" #include "utils/builtins.h" #include "utils/fmgroids.h" #include "utils/inval.h" #include "utils/lsyscache.h" #include "utils/memutils.h" #include "utils/partcache.h" #include "utils/relcache.h" #include "utils/ruleutils.h" #include "utils/snapmgr.h" #include "utils/syscache.h" #include "utils/timestamp.h" #include "utils/typcache.h" #include "utils/usercontext.h" /* * ON COMMIT action list */ typedef struct OnCommitItem { Oid relid; /* relid of relation */ OnCommitAction oncommit; /* what to do at end of xact */ /* * If this entry was created during the current transaction, * creating_subid is the ID of the creating subxact; if created in a prior * transaction, creating_subid is zero. If deleted during the current * transaction, deleting_subid is the ID of the deleting subxact; if no * deletion request is pending, deleting_subid is zero. */ SubTransactionId creating_subid; SubTransactionId deleting_subid; } OnCommitItem; static List *on_commits = NIL; /* * State information for ALTER TABLE * * The pending-work queue for an ALTER TABLE is a List of AlteredTableInfo * structs, one for each table modified by the operation (the named table * plus any child tables that are affected). We save lists of subcommands * to apply to this table (possibly modified by parse transformation steps); * these lists will be executed in Phase 2. If a Phase 3 step is needed, * necessary information is stored in the constraints and newvals lists. * * Phase 2 is divided into multiple passes; subcommands are executed in * a pass determined by subcommand type. */ typedef enum AlterTablePass { AT_PASS_UNSET = -1, /* UNSET will cause ERROR */ AT_PASS_DROP, /* DROP (all flavors) */ AT_PASS_ALTER_TYPE, /* ALTER COLUMN TYPE */ AT_PASS_ADD_COL, /* ADD COLUMN */ AT_PASS_SET_EXPRESSION, /* ALTER SET EXPRESSION */ AT_PASS_OLD_INDEX, /* re-add existing indexes */ AT_PASS_OLD_CONSTR, /* re-add existing constraints */ /* We could support a RENAME COLUMN pass here, but not currently used */ AT_PASS_ADD_CONSTR, /* ADD constraints (initial examination) */ AT_PASS_COL_ATTRS, /* set column attributes, eg NOT NULL */ AT_PASS_ADD_INDEXCONSTR, /* ADD index-based constraints */ AT_PASS_ADD_INDEX, /* ADD indexes */ AT_PASS_ADD_OTHERCONSTR, /* ADD other constraints, defaults */ AT_PASS_MISC, /* other stuff */ } AlterTablePass; #define AT_NUM_PASSES (AT_PASS_MISC + 1) typedef struct AlteredTableInfo { /* Information saved before any work commences: */ Oid relid; /* Relation to work on */ char relkind; /* Its relkind */ TupleDesc oldDesc; /* Pre-modification tuple descriptor */ /* * Transiently set during Phase 2, normally set to NULL. * * ATRewriteCatalogs sets this when it starts, and closes when ATExecCmd * returns control. This can be exploited by ATExecCmd subroutines to * close/reopen across transaction boundaries. */ Relation rel; /* Information saved by Phase 1 for Phase 2: */ List *subcmds[AT_NUM_PASSES]; /* Lists of AlterTableCmd */ /* Information saved by Phases 1/2 for Phase 3: */ List *constraints; /* List of NewConstraint */ List *newvals; /* List of NewColumnValue */ List *afterStmts; /* List of utility command parsetrees */ bool verify_new_notnull; /* T if we should recheck NOT NULL */ int rewrite; /* Reason for forced rewrite, if any */ bool chgAccessMethod; /* T if SET ACCESS METHOD is used */ Oid newAccessMethod; /* new access method; 0 means no change, * if above is true */ Oid newTableSpace; /* new tablespace; 0 means no change */ bool chgPersistence; /* T if SET LOGGED/UNLOGGED is used */ char newrelpersistence; /* if above is true */ Expr *partition_constraint; /* for attach partition validation */ /* true, if validating default due to some other attach/detach */ bool validate_default; /* Objects to rebuild after completing ALTER TYPE operations */ List *changedConstraintOids; /* OIDs of constraints to rebuild */ List *changedConstraintDefs; /* string definitions of same */ List *changedIndexOids; /* OIDs of indexes to rebuild */ List *changedIndexDefs; /* string definitions of same */ char *replicaIdentityIndex; /* index to reset as REPLICA IDENTITY */ char *clusterOnIndex; /* index to use for CLUSTER */ List *changedStatisticsOids; /* OIDs of statistics to rebuild */ List *changedStatisticsDefs; /* string definitions of same */ List *changedStatisticsOwners; /* owners of same */ } AlteredTableInfo; /* Struct describing one new constraint to check in Phase 3 scan */ /* Note: new not-null constraints are handled elsewhere */ typedef struct NewConstraint { char *name; /* Constraint name, or NULL if none */ ConstrType contype; /* CHECK or FOREIGN */ Oid refrelid; /* PK rel, if FOREIGN */ Oid refindid; /* OID of PK's index, if FOREIGN */ bool conwithperiod; /* Whether the new FOREIGN KEY uses PERIOD */ Oid conid; /* OID of pg_constraint entry, if FOREIGN */ Node *qual; /* Check expr or CONSTR_FOREIGN Constraint */ ExprState *qualstate; /* Execution state for CHECK expr */ } NewConstraint; /* * Struct describing one new column value that needs to be computed during * Phase 3 copy (this could be either a new column with a non-null default, or * a column that we're changing the type of). Columns without such an entry * are just copied from the old table during ATRewriteTable. Note that the * expr is an expression over *old* table values, except when is_generated * is true; then it is an expression over columns of the *new* tuple. */ typedef struct NewColumnValue { AttrNumber attnum; /* which column */ Expr *expr; /* expression to compute */ ExprState *exprstate; /* execution state */ bool is_generated; /* is it a GENERATED expression? */ } NewColumnValue; /* * Error-reporting support for RemoveRelations */ struct dropmsgstrings { char kind; int nonexistent_code; const char *nonexistent_msg; const char *skipping_msg; const char *nota_msg; const char *drophint_msg; }; static const struct dropmsgstrings dropmsgstringarray[] = { {RELKIND_RELATION, ERRCODE_UNDEFINED_TABLE, gettext_noop("table \"%s\" does not exist"), gettext_noop("table \"%s\" does not exist, skipping"), gettext_noop("\"%s\" is not a table"), gettext_noop("Use DROP TABLE to remove a table.")}, {RELKIND_SEQUENCE, ERRCODE_UNDEFINED_TABLE, gettext_noop("sequence \"%s\" does not exist"), gettext_noop("sequence \"%s\" does not exist, skipping"), gettext_noop("\"%s\" is not a sequence"), gettext_noop("Use DROP SEQUENCE to remove a sequence.")}, {RELKIND_VIEW, ERRCODE_UNDEFINED_TABLE, gettext_noop("view \"%s\" does not exist"), gettext_noop("view \"%s\" does not exist, skipping"), gettext_noop("\"%s\" is not a view"), gettext_noop("Use DROP VIEW to remove a view.")}, {RELKIND_MATVIEW, ERRCODE_UNDEFINED_TABLE, gettext_noop("materialized view \"%s\" does not exist"), gettext_noop("materialized view \"%s\" does not exist, skipping"), gettext_noop("\"%s\" is not a materialized view"), gettext_noop("Use DROP MATERIALIZED VIEW to remove a materialized view.")}, {RELKIND_INDEX, ERRCODE_UNDEFINED_OBJECT, gettext_noop("index \"%s\" does not exist"), gettext_noop("index \"%s\" does not exist, skipping"), gettext_noop("\"%s\" is not an index"), gettext_noop("Use DROP INDEX to remove an index.")}, {RELKIND_COMPOSITE_TYPE, ERRCODE_UNDEFINED_OBJECT, gettext_noop("type \"%s\" does not exist"), gettext_noop("type \"%s\" does not exist, skipping"), gettext_noop("\"%s\" is not a type"), gettext_noop("Use DROP TYPE to remove a type.")}, {RELKIND_FOREIGN_TABLE, ERRCODE_UNDEFINED_OBJECT, gettext_noop("foreign table \"%s\" does not exist"), gettext_noop("foreign table \"%s\" does not exist, skipping"), gettext_noop("\"%s\" is not a foreign table"), gettext_noop("Use DROP FOREIGN TABLE to remove a foreign table.")}, {RELKIND_PARTITIONED_TABLE, ERRCODE_UNDEFINED_TABLE, gettext_noop("table \"%s\" does not exist"), gettext_noop("table \"%s\" does not exist, skipping"), gettext_noop("\"%s\" is not a table"), gettext_noop("Use DROP TABLE to remove a table.")}, {RELKIND_PARTITIONED_INDEX, ERRCODE_UNDEFINED_OBJECT, gettext_noop("index \"%s\" does not exist"), gettext_noop("index \"%s\" does not exist, skipping"), gettext_noop("\"%s\" is not an index"), gettext_noop("Use DROP INDEX to remove an index.")}, {RELKIND_PROPGRAPH, ERRCODE_UNDEFINED_OBJECT, gettext_noop("property graph \"%s\" does not exist"), gettext_noop("property graph \"%s\" does not exist, skipping"), gettext_noop("\"%s\" is not a property graph"), gettext_noop("Use DROP PROPERTY GRAPH to remove a property graph.")}, {'\0', 0, NULL, NULL, NULL, NULL} }; /* communication between RemoveRelations and RangeVarCallbackForDropRelation */ struct DropRelationCallbackState { /* These fields are set by RemoveRelations: */ char expected_relkind; LOCKMODE heap_lockmode; /* These fields are state to track which subsidiary locks are held: */ Oid heapOid; Oid partParentOid; /* These fields are passed back by RangeVarCallbackForDropRelation: */ char actual_relkind; char actual_relpersistence; }; /* Alter table target-type flags for ATSimplePermissions */ #define ATT_TABLE 0x0001 #define ATT_VIEW 0x0002 #define ATT_MATVIEW 0x0004 #define ATT_INDEX 0x0008 #define ATT_COMPOSITE_TYPE 0x0010 #define ATT_FOREIGN_TABLE 0x0020 #define ATT_PARTITIONED_INDEX 0x0040 #define ATT_SEQUENCE 0x0080 #define ATT_PARTITIONED_TABLE 0x0100 /* * ForeignTruncateInfo * * Information related to truncation of foreign tables. This is used for * the elements in a hash table. It uses the server OID as lookup key, * and includes a per-server list of all foreign tables involved in the * truncation. */ typedef struct ForeignTruncateInfo { Oid serverid; List *rels; } ForeignTruncateInfo; /* Partial or complete FK creation in addFkConstraint() */ typedef enum addFkConstraintSides { addFkReferencedSide, addFkReferencingSide, addFkBothSides, } addFkConstraintSides; /* * Hold extension dependencies of one partition index, during * MERGE/SPLIT PARTITION processing. * * collectPartitionIndexExtDeps() builds a list of these entries sorted by * parentIndexOid with exactly one entry per parent partitioned index; the * list is then consumed by applyPartitionIndexExtDeps() to re-record the * same dependencies on the newly created partition's indexes. * * extensionOids is kept sorted ascending so that equality checks between * entries from different partitions can be done in a single pass. * indexOid is carried only so that conflict errors can cite specific * partition index names. */ typedef struct PartitionIndexExtDepEntry { Oid parentIndexOid; /* OID of the parent partitioned index */ Oid indexOid; /* OID of a representative partition index */ List *extensionOids; /* OIDs of dependent extensions, sorted asc */ } PartitionIndexExtDepEntry; /* * Partition tables are expected to be dropped when the parent partitioned * table gets dropped. Hence for partitioning we use AUTO dependency. * Otherwise, for regular inheritance use NORMAL dependency. */ #define child_dependency_type(child_is_partition) \ ((child_is_partition) ? DEPENDENCY_AUTO : DEPENDENCY_NORMAL) static void truncate_check_rel(Oid relid, Form_pg_class reltuple); static void truncate_check_perms(Oid relid, Form_pg_class reltuple); static void truncate_check_activity(Relation rel); static void RangeVarCallbackForTruncate(const RangeVar *relation, Oid relId, Oid oldRelId, void *arg); static List *MergeAttributes(List *columns, const List *supers, char relpersistence, bool is_partition, List **supconstr, List **supnotnulls); static List *MergeCheckConstraint(List *constraints, const char *name, Node *expr, bool is_enforced); static void MergeChildAttribute(List *inh_columns, int exist_attno, int newcol_attno, const ColumnDef *newdef); static ColumnDef *MergeInheritedAttribute(List *inh_columns, int exist_attno, const ColumnDef *newdef); static void MergeAttributesIntoExisting(Relation child_rel, Relation parent_rel, bool ispartition); static void MergeConstraintsIntoExisting(Relation child_rel, Relation parent_rel); static void StoreCatalogInheritance(Oid relationId, List *supers, bool child_is_partition); static void StoreCatalogInheritance1(Oid relationId, Oid parentOid, int32 seqNumber, Relation inhRelation, bool child_is_partition); static int findAttrByName(const char *attributeName, const List *columns); static void AlterIndexNamespaces(Relation classRel, Relation rel, Oid oldNspOid, Oid newNspOid, ObjectAddresses *objsMoved); static void AlterSeqNamespaces(Relation classRel, Relation rel, Oid oldNspOid, Oid newNspOid, ObjectAddresses *objsMoved, LOCKMODE lockmode); static ObjectAddress ATExecAlterConstraint(List **wqueue, Relation rel, ATAlterConstraint *cmdcon, bool recurse, LOCKMODE lockmode); static bool ATExecAlterConstraintInternal(List **wqueue, ATAlterConstraint *cmdcon, Relation conrel, Relation tgrel, Relation rel, HeapTuple contuple, bool recurse, LOCKMODE lockmode); static bool ATExecAlterFKConstrEnforceability(List **wqueue, ATAlterConstraint *cmdcon, Relation conrel, Relation tgrel, Oid fkrelid, Oid pkrelid, HeapTuple contuple, LOCKMODE lockmode, Oid ReferencedParentDelTrigger, Oid ReferencedParentUpdTrigger, Oid ReferencingParentInsTrigger, Oid ReferencingParentUpdTrigger); static bool ATExecAlterCheckConstrEnforceability(List **wqueue, ATAlterConstraint *cmdcon, Relation conrel, HeapTuple contuple, bool recurse, bool recursing, List *changing_conids, LOCKMODE lockmode); static bool ATExecAlterConstrDeferrability(List **wqueue, ATAlterConstraint *cmdcon, Relation conrel, Relation tgrel, Relation rel, HeapTuple contuple, bool recurse, List **otherrelids, LOCKMODE lockmode); static bool ATExecAlterConstrInheritability(List **wqueue, ATAlterConstraint *cmdcon, Relation conrel, Relation rel, HeapTuple contuple, LOCKMODE lockmode); static void AlterConstrTriggerDeferrability(Oid conoid, Relation tgrel, Relation rel, bool deferrable, bool initdeferred, List **otherrelids); static void AlterFKConstrEnforceabilityRecurse(List **wqueue, ATAlterConstraint *cmdcon, Relation conrel, Relation tgrel, Oid fkrelid, Oid pkrelid, HeapTuple contuple, LOCKMODE lockmode, Oid ReferencedParentDelTrigger, Oid ReferencedParentUpdTrigger, Oid ReferencingParentInsTrigger, Oid ReferencingParentUpdTrigger); static void AlterCheckConstrEnforceabilityRecurse(List **wqueue, ATAlterConstraint *cmdcon, Relation conrel, Oid conrelid, bool recurse, bool recursing, List *changing_conids, LOCKMODE lockmode); static void AlterConstrDeferrabilityRecurse(List **wqueue, ATAlterConstraint *cmdcon, Relation conrel, Relation tgrel, Relation rel, HeapTuple contuple, bool recurse, List **otherrelids, LOCKMODE lockmode); static void AlterConstrUpdateConstraintEntry(ATAlterConstraint *cmdcon, Relation conrel, HeapTuple contuple); static bool ATCheckCheckConstrHasEnforcedParent(Relation conrel, Relation rel, HeapTuple contuple, List *changing_conids, Oid *enforced_parentoid); static ObjectAddress ATExecValidateConstraint(List **wqueue, Relation rel, char *constrName, bool recurse, bool recursing, LOCKMODE lockmode); static void QueueFKConstraintValidation(List **wqueue, Relation conrel, Relation fkrel, Oid pkrelid, HeapTuple contuple, LOCKMODE lockmode); static void QueueCheckConstraintValidation(List **wqueue, Relation conrel, Relation rel, char *constrName, HeapTuple contuple, bool recurse, bool recursing, LOCKMODE lockmode); static void QueueNNConstraintValidation(List **wqueue, Relation conrel, Relation rel, HeapTuple contuple, bool recurse, bool recursing, LOCKMODE lockmode); static bool constraints_equivalent(HeapTuple a, HeapTuple b, TupleDesc tupleDesc); static int transformColumnNameList(Oid relId, List *colList, int16 *attnums, Oid *atttypids, Oid *attcollids); static int transformFkeyGetPrimaryKey(Relation pkrel, Oid *indexOid, List **attnamelist, int16 *attnums, Oid *atttypids, Oid *attcollids, Oid *opclasses, bool *pk_has_without_overlaps); static Oid transformFkeyCheckAttrs(Relation pkrel, int numattrs, int16 *attnums, bool with_period, Oid *opclasses, bool *pk_has_without_overlaps); static void checkFkeyPermissions(Relation rel, int16 *attnums, int natts); static CoercionPathType findFkeyCast(Oid targetTypeId, Oid sourceTypeId, Oid *funcid); static void validateForeignKeyConstraint(char *conname, Relation rel, Relation pkrel, Oid pkindOid, Oid constraintOid, bool hasperiod); static void CheckAlterTableIsSafe(Relation rel); static void ATController(AlterTableStmt *parsetree, Relation rel, List *cmds, bool recurse, LOCKMODE lockmode, AlterTableUtilityContext *context); static void ATPrepCmd(List **wqueue, Relation rel, AlterTableCmd *cmd, bool recurse, bool recursing, LOCKMODE lockmode, AlterTableUtilityContext *context); static void ATRewriteCatalogs(List **wqueue, LOCKMODE lockmode, AlterTableUtilityContext *context); static void ATExecCmd(List **wqueue, AlteredTableInfo *tab, AlterTableCmd *cmd, LOCKMODE lockmode, AlterTablePass cur_pass, AlterTableUtilityContext *context); static AlterTableCmd *ATParseTransformCmd(List **wqueue, AlteredTableInfo *tab, Relation rel, AlterTableCmd *cmd, bool recurse, LOCKMODE lockmode, AlterTablePass cur_pass, AlterTableUtilityContext *context); static void ATRewriteTables(AlterTableStmt *parsetree, List **wqueue, LOCKMODE lockmode, AlterTableUtilityContext *context); static void ATRewriteTable(AlteredTableInfo *tab, Oid OIDNewHeap); static AlteredTableInfo *ATGetQueueEntry(List **wqueue, Relation rel); static void ATSimplePermissions(AlterTableType cmdtype, Relation rel, int allowed_targets); static void ATSimpleRecursion(List **wqueue, Relation rel, AlterTableCmd *cmd, bool recurse, LOCKMODE lockmode, AlterTableUtilityContext *context); static void ATCheckPartitionsNotInUse(Relation rel, LOCKMODE lockmode); static void ATTypedTableRecursion(List **wqueue, Relation rel, AlterTableCmd *cmd, LOCKMODE lockmode, AlterTableUtilityContext *context); static List *find_typed_table_dependencies(Oid typeOid, const char *typeName, DropBehavior behavior); static void ATPrepAddColumn(List **wqueue, Relation rel, bool recurse, bool recursing, bool is_view, AlterTableCmd *cmd, LOCKMODE lockmode, AlterTableUtilityContext *context); static ObjectAddress ATExecAddColumn(List **wqueue, AlteredTableInfo *tab, Relation rel, AlterTableCmd **cmd, bool recurse, bool recursing, LOCKMODE lockmode, AlterTablePass cur_pass, AlterTableUtilityContext *context); static bool check_for_column_name_collision(Relation rel, const char *colname, bool if_not_exists); static void add_column_datatype_dependency(Oid relid, int32 attnum, Oid typid); static void add_column_collation_dependency(Oid relid, int32 attnum, Oid collid); static ObjectAddress ATExecDropNotNull(Relation rel, const char *colName, bool recurse, LOCKMODE lockmode); static void set_attnotnull(List **wqueue, Relation rel, AttrNumber attnum, bool queue_validation); static ObjectAddress ATExecSetNotNull(List **wqueue, Relation rel, char *conName, char *colName, bool recurse, bool recursing, LOCKMODE lockmode); static bool NotNullImpliedByRelConstraints(Relation rel, Form_pg_attribute attr); static bool ConstraintImpliedByRelConstraint(Relation scanrel, List *testConstraint, List *provenConstraint); static ObjectAddress ATExecColumnDefault(Relation rel, const char *colName, Node *newDefault, LOCKMODE lockmode); static ObjectAddress ATExecCookedColumnDefault(Relation rel, AttrNumber attnum, Node *newDefault); static ObjectAddress ATExecAddIdentity(Relation rel, const char *colName, Node *def, LOCKMODE lockmode, bool recurse, bool recursing); static ObjectAddress ATExecSetIdentity(Relation rel, const char *colName, Node *def, LOCKMODE lockmode, bool recurse, bool recursing); static ObjectAddress ATExecDropIdentity(Relation rel, const char *colName, bool missing_ok, LOCKMODE lockmode, bool recurse, bool recursing); static ObjectAddress ATExecSetExpression(AlteredTableInfo *tab, Relation rel, const char *colName, Node *newExpr, LOCKMODE lockmode); static void ATPrepDropExpression(Relation rel, AlterTableCmd *cmd, bool recurse, bool recursing, LOCKMODE lockmode); static ObjectAddress ATExecDropExpression(Relation rel, const char *colName, bool missing_ok, LOCKMODE lockmode); static ObjectAddress ATExecSetStatistics(Relation rel, const char *colName, int16 colNum, Node *newValue, LOCKMODE lockmode); static ObjectAddress ATExecSetOptions(Relation rel, const char *colName, Node *options, bool isReset, LOCKMODE lockmode); static ObjectAddress ATExecSetStorage(Relation rel, const char *colName, Node *newValue, LOCKMODE lockmode); static void ATPrepDropColumn(List **wqueue, Relation rel, bool recurse, bool recursing, AlterTableCmd *cmd, LOCKMODE lockmode, AlterTableUtilityContext *context); static ObjectAddress ATExecDropColumn(List **wqueue, Relation rel, const char *colName, DropBehavior behavior, bool recurse, bool recursing, bool missing_ok, LOCKMODE lockmode, ObjectAddresses *addrs); static void ATPrepAddPrimaryKey(List **wqueue, Relation rel, AlterTableCmd *cmd, bool recurse, LOCKMODE lockmode, AlterTableUtilityContext *context); static void verifyNotNullPKCompatible(HeapTuple tuple, const char *colname); static ObjectAddress ATExecAddIndex(AlteredTableInfo *tab, Relation rel, IndexStmt *stmt, bool is_rebuild, LOCKMODE lockmode); static ObjectAddress ATExecAddStatistics(AlteredTableInfo *tab, Relation rel, CreateStatsStmt *stmt, bool is_rebuild, LOCKMODE lockmode); static ObjectAddress ATExecAddConstraint(List **wqueue, AlteredTableInfo *tab, Relation rel, Constraint *newConstraint, bool recurse, bool is_readd, LOCKMODE lockmode); static char *ChooseForeignKeyConstraintNameAddition(List *colnames); static ObjectAddress ATExecAddIndexConstraint(AlteredTableInfo *tab, Relation rel, IndexStmt *stmt, LOCKMODE lockmode); static ObjectAddress ATAddCheckNNConstraint(List **wqueue, AlteredTableInfo *tab, Relation rel, Constraint *constr, bool recurse, bool recursing, bool is_readd, LOCKMODE lockmode); static ObjectAddress ATAddForeignKeyConstraint(List **wqueue, AlteredTableInfo *tab, Relation rel, Constraint *fkconstraint, bool recurse, bool recursing, LOCKMODE lockmode); static int validateFkOnDeleteSetColumns(int numfks, const int16 *fkattnums, int numfksetcols, int16 *fksetcolsattnums, List *fksetcols); static ObjectAddress addFkConstraint(addFkConstraintSides fkside, char *constraintname, Constraint *fkconstraint, Relation rel, Relation pkrel, Oid indexOid, Oid parentConstr, int numfks, int16 *pkattnum, int16 *fkattnum, Oid *pfeqoperators, Oid *ppeqoperators, Oid *ffeqoperators, int numfkdelsetcols, int16 *fkdelsetcols, bool is_internal, bool with_period); static void addFkRecurseReferenced(Constraint *fkconstraint, Relation rel, Relation pkrel, Oid indexOid, Oid parentConstr, int numfks, int16 *pkattnum, int16 *fkattnum, Oid *pfeqoperators, Oid *ppeqoperators, Oid *ffeqoperators, int numfkdelsetcols, int16 *fkdelsetcols, bool old_check_ok, Oid parentDelTrigger, Oid parentUpdTrigger, bool with_period); static void addFkRecurseReferencing(List **wqueue, Constraint *fkconstraint, Relation rel, Relation pkrel, Oid indexOid, Oid parentConstr, int numfks, int16 *pkattnum, int16 *fkattnum, Oid *pfeqoperators, Oid *ppeqoperators, Oid *ffeqoperators, int numfkdelsetcols, int16 *fkdelsetcols, bool old_check_ok, LOCKMODE lockmode, Oid parentInsTrigger, Oid parentUpdTrigger, bool with_period); static void CloneForeignKeyConstraints(List **wqueue, Relation parentRel, Relation partitionRel); static void CloneFkReferenced(Relation parentRel, Relation partitionRel); static void CloneFkReferencing(List **wqueue, Relation parentRel, Relation partRel); static void createForeignKeyCheckTriggers(Oid myRelOid, Oid refRelOid, Constraint *fkconstraint, Oid constraintOid, Oid indexOid, Oid parentInsTrigger, Oid parentUpdTrigger, Oid *insertTrigOid, Oid *updateTrigOid); static void createForeignKeyActionTriggers(Oid myRelOid, Oid refRelOid, Constraint *fkconstraint, Oid constraintOid, Oid indexOid, Oid parentDelTrigger, Oid parentUpdTrigger, Oid *deleteTrigOid, Oid *updateTrigOid); static bool tryAttachPartitionForeignKey(List **wqueue, ForeignKeyCacheInfo *fk, Relation partition, Oid parentConstrOid, int numfks, AttrNumber *mapped_conkey, AttrNumber *confkey, Oid *conpfeqop, Oid parentInsTrigger, Oid parentUpdTrigger, Relation trigrel); static void AttachPartitionForeignKey(List **wqueue, Relation partition, Oid partConstrOid, Oid parentConstrOid, Oid parentInsTrigger, Oid parentUpdTrigger, Relation trigrel); static void RemoveInheritedConstraint(Relation conrel, Relation trigrel, Oid conoid, Oid conrelid); static void DropForeignKeyConstraintTriggers(Relation trigrel, Oid conoid, Oid confrelid, Oid conrelid); static void GetForeignKeyActionTriggers(Relation trigrel, Oid conoid, Oid confrelid, Oid conrelid, Oid *deleteTriggerOid, Oid *updateTriggerOid); static void GetForeignKeyCheckTriggers(Relation trigrel, Oid conoid, Oid confrelid, Oid conrelid, Oid *insertTriggerOid, Oid *updateTriggerOid); static void ATExecDropConstraint(Relation rel, const char *constrName, DropBehavior behavior, bool recurse, bool missing_ok, LOCKMODE lockmode); static ObjectAddress dropconstraint_internal(Relation rel, HeapTuple constraintTup, DropBehavior behavior, bool recurse, bool recursing, bool missing_ok, LOCKMODE lockmode); static void ATPrepAlterColumnType(List **wqueue, AlteredTableInfo *tab, Relation rel, bool recurse, bool recursing, AlterTableCmd *cmd, LOCKMODE lockmode, AlterTableUtilityContext *context); static bool ATColumnChangeRequiresRewrite(Node *expr, AttrNumber varattno); static ObjectAddress ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel, AlterTableCmd *cmd, LOCKMODE lockmode); static void RememberAllDependentForRebuilding(AlteredTableInfo *tab, AlterTableType subtype, Relation rel, AttrNumber attnum, const char *colName); static void RememberWholeRowDependentForRebuilding(AlteredTableInfo *tab, AlterTableType subtype, Relation rel); static void RememberConstraintForRebuilding(Oid conoid, AlteredTableInfo *tab); static void RememberIndexForRebuilding(Oid indoid, AlteredTableInfo *tab); static void RememberStatisticsForRebuilding(Oid stxoid, AlteredTableInfo *tab); static void ATPostAlterTypeCleanup(List **wqueue, AlteredTableInfo *tab, LOCKMODE lockmode); static void ATPostAlterTypeParse(Oid oldId, Oid oldRelId, Oid refRelId, Oid ownerId, char *cmd, List **wqueue, LOCKMODE lockmode, bool rewrite); static void RebuildConstraintComment(AlteredTableInfo *tab, AlterTablePass pass, Oid objid, Relation rel, List *domname, const char *conname); static void TryReuseIndex(Oid oldId, IndexStmt *stmt); static void TryReuseForeignKey(Oid oldId, Constraint *con); static ObjectAddress ATExecAlterColumnGenericOptions(Relation rel, const char *colName, List *options, LOCKMODE lockmode); static void change_owner_fix_column_acls(Oid relationOid, Oid oldOwnerId, Oid newOwnerId); static void change_owner_recurse_to_sequences(Oid relationOid, Oid newOwnerId, LOCKMODE lockmode); static ObjectAddress ATExecClusterOn(Relation rel, const char *indexName, LOCKMODE lockmode); static void ATExecDropCluster(Relation rel, LOCKMODE lockmode); static void ATPrepSetAccessMethod(AlteredTableInfo *tab, Relation rel, const char *amname); static void ATExecSetAccessMethodNoStorage(Relation rel, Oid newAccessMethodId); static void ATPrepChangePersistence(AlteredTableInfo *tab, Relation rel, bool toLogged); static void ATPrepSetTableSpace(AlteredTableInfo *tab, Relation rel, const char *tablespacename, LOCKMODE lockmode); static void ATExecSetTableSpace(Oid tableOid, Oid newTableSpace, LOCKMODE lockmode); static void ATExecSetTableSpaceNoStorage(Relation rel, Oid newTableSpace); static void ATExecSetRelOptions(Relation rel, List *defList, AlterTableType operation, LOCKMODE lockmode); static void ATExecEnableDisableTrigger(Relation rel, const char *trigname, char fires_when, bool skip_system, bool recurse, LOCKMODE lockmode); static void ATExecEnableDisableRule(Relation rel, const char *rulename, char fires_when, LOCKMODE lockmode); static void ATPrepChangeInherit(Relation child_rel); static ObjectAddress ATExecAddInherit(Relation child_rel, RangeVar *parent, LOCKMODE lockmode); static ObjectAddress ATExecDropInherit(Relation rel, RangeVar *parent, LOCKMODE lockmode); static void drop_parent_dependency(Oid relid, Oid refclassid, Oid refobjid, DependencyType deptype); static ObjectAddress ATExecAddOf(Relation rel, const TypeName *ofTypename, LOCKMODE lockmode); static void ATExecDropOf(Relation rel, LOCKMODE lockmode); static void ATExecReplicaIdentity(Relation rel, ReplicaIdentityStmt *stmt, LOCKMODE lockmode); static void ATExecGenericOptions(Relation rel, List *options); static void ATExecSetRowSecurity(Relation rel, bool rls); static void ATExecForceNoForceRowSecurity(Relation rel, bool force_rls); static ObjectAddress ATExecSetCompression(Relation rel, const char *column, Node *newValue, LOCKMODE lockmode); static void index_copy_data(Relation rel, RelFileLocator newrlocator); static const char *storage_name(char c); static void RangeVarCallbackForDropRelation(const RangeVar *rel, Oid relOid, Oid oldRelOid, void *arg); static void RangeVarCallbackForAlterRelation(const RangeVar *rv, Oid relid, Oid oldrelid, void *arg); static PartitionSpec *transformPartitionSpec(Relation rel, PartitionSpec *partspec); static void ComputePartitionAttrs(ParseState *pstate, Relation rel, List *partParams, AttrNumber *partattrs, List **partexprs, Oid *partopclass, Oid *partcollation, PartitionStrategy strategy); static void CreateInheritance(Relation child_rel, Relation parent_rel, bool ispartition); static void RemoveInheritance(Relation child_rel, Relation parent_rel, bool expect_detached); static ObjectAddress ATExecAttachPartition(List **wqueue, Relation rel, PartitionCmd *cmd, AlterTableUtilityContext *context); static void AttachPartitionEnsureIndexes(List **wqueue, Relation rel, Relation attachrel); static void QueuePartitionConstraintValidation(List **wqueue, Relation scanrel, List *partConstraint, bool validate_default); static void CloneRowTriggersToPartition(Relation parent, Relation partition); static void DropClonedTriggersFromPartition(Oid partitionId); static ObjectAddress ATExecDetachPartition(List **wqueue, AlteredTableInfo *tab, Relation rel, RangeVar *name, bool concurrent); static void DetachPartitionFinalize(Relation rel, Relation partRel, bool concurrent, Oid defaultPartOid); static ObjectAddress ATExecDetachPartitionFinalize(Relation rel, RangeVar *name); static ObjectAddress ATExecAttachPartitionIdx(List **wqueue, Relation parentIdx, RangeVar *name); static void validatePartitionedIndex(Relation partedIdx, Relation partedTbl); static void refuseDupeIndexAttach(Relation parentIdx, Relation partIdx, Relation partitionTbl); static void verifyPartitionIndexNotNull(IndexInfo *iinfo, Relation partition); static List *GetParentedForeignKeyRefs(Relation partition); static void ATDetachCheckNoForeignKeyRefs(Relation partition); static char GetAttributeCompression(Oid atttypid, const char *compression); static char GetAttributeStorage(Oid atttypid, const char *storagemode); static void ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel, PartitionCmd *cmd, AlterTableUtilityContext *context); static void ATExecSplitPartition(List **wqueue, AlteredTableInfo *tab, Relation rel, PartitionCmd *cmd, AlterTableUtilityContext *context); static List *collectPartitionIndexExtDeps(List *partitionOids); static void applyPartitionIndexExtDeps(Oid newPartOid, List *extDepState); static void freePartitionIndexExtDeps(List *extDepState); /* ---------------------------------------------------------------- * DefineRelation * Creates a new relation. * * stmt carries parsetree information from an ordinary CREATE TABLE statement. * The other arguments are used to extend the behavior for other cases: * relkind: relkind to assign to the new relation * ownerId: if not InvalidOid, use this as the new relation's owner. * typaddress: if not null, it's set to the pg_type entry's address. * queryString: for error reporting * * Note that permissions checks are done against current user regardless of * ownerId. A nonzero ownerId is used when someone is creating a relation * "on behalf of" someone else, so we still want to see that the current user * has permissions to do it. * * If successful, returns the address of the new relation. * ---------------------------------------------------------------- */ ObjectAddress DefineRelation(CreateStmt *stmt, char relkind, Oid ownerId, ObjectAddress *typaddress, const char *queryString) { char relname[NAMEDATALEN]; Oid namespaceId; Oid relationId; Oid tablespaceId; Relation rel; TupleDesc descriptor; List *inheritOids; List *old_constraints; List *old_notnulls; List *rawDefaults; List *cookedDefaults; List *nncols; List *connames = NIL; Datum reloptions; ListCell *listptr; AttrNumber attnum; bool partitioned; const char *const validnsps[] = HEAP_RELOPT_NAMESPACES; Oid ofTypeId; ObjectAddress address; LOCKMODE parentLockmode; Oid accessMethodId = InvalidOid; /* * Truncate relname to appropriate length (probably a waste of time, as * parser should have done this already). */ strlcpy(relname, stmt->relation->relname, NAMEDATALEN); /* * Check consistency of arguments */ if (stmt->oncommit != ONCOMMIT_NOOP && stmt->relation->relpersistence != RELPERSISTENCE_TEMP) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("ON COMMIT can only be used on temporary tables"))); if (stmt->partspec != NULL) { if (relkind != RELKIND_RELATION) elog(ERROR, "unexpected relkind: %d", (int) relkind); relkind = RELKIND_PARTITIONED_TABLE; partitioned = true; } else partitioned = false; if (relkind == RELKIND_PARTITIONED_TABLE && stmt->relation->relpersistence == RELPERSISTENCE_UNLOGGED) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("partitioned tables cannot be unlogged"))); /* * Look up the namespace in which we are supposed to create the relation, * check we have permission to create there, lock it against concurrent * drop, and mark stmt->relation as RELPERSISTENCE_TEMP if a temporary * namespace is selected. */ namespaceId = RangeVarGetAndCheckCreationNamespace(stmt->relation, NoLock, NULL); /* * Security check: disallow creating temp tables from security-restricted * code. This is needed because calling code might not expect untrusted * tables to appear in pg_temp at the front of its search path. */ if (stmt->relation->relpersistence == RELPERSISTENCE_TEMP && InSecurityRestrictedOperation()) ereport(ERROR, (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), errmsg("cannot create temporary table within security-restricted operation"))); /* * Determine the lockmode to use when scanning parents. A self-exclusive * lock is needed here. * * For regular inheritance, if two backends attempt to add children to the * same parent simultaneously, and that parent has no pre-existing * children, then both will attempt to update the parent's relhassubclass * field, leading to a "tuple concurrently updated" error. Also, this * interlocks against a concurrent ANALYZE on the parent table, which * might otherwise be attempting to clear the parent's relhassubclass * field, if its previous children were recently dropped. * * If the child table is a partition, then we instead grab an exclusive * lock on the parent because its partition descriptor will be changed by * addition of the new partition. */ parentLockmode = (stmt->partbound != NULL ? AccessExclusiveLock : ShareUpdateExclusiveLock); /* Determine the list of OIDs of the parents. */ inheritOids = NIL; foreach(listptr, stmt->inhRelations) { RangeVar *rv = (RangeVar *) lfirst(listptr); Oid parentOid; parentOid = RangeVarGetRelid(rv, parentLockmode, false); /* * Reject duplications in the list of parents. */ if (list_member_oid(inheritOids, parentOid)) ereport(ERROR, (errcode(ERRCODE_DUPLICATE_TABLE), errmsg("relation \"%s\" would be inherited from more than once", get_rel_name(parentOid)))); inheritOids = lappend_oid(inheritOids, parentOid); } /* * Select tablespace to use: an explicitly indicated one, or (in the case * of a partitioned table) the parent's, if it has one. */ if (stmt->tablespacename) { tablespaceId = get_tablespace_oid(stmt->tablespacename, false); if (partitioned && tablespaceId == MyDatabaseTableSpace) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot specify default tablespace for partitioned relations"))); } else if (stmt->partbound) { Assert(list_length(inheritOids) == 1); tablespaceId = get_rel_tablespace(linitial_oid(inheritOids)); } else tablespaceId = InvalidOid; /* still nothing? use the default */ if (!OidIsValid(tablespaceId)) tablespaceId = GetDefaultTablespace(stmt->relation->relpersistence, partitioned); /* Check permissions except when using database's default */ if (OidIsValid(tablespaceId) && tablespaceId != MyDatabaseTableSpace) { AclResult aclresult; aclresult = object_aclcheck(TableSpaceRelationId, tablespaceId, GetUserId(), ACL_CREATE); if (aclresult != ACLCHECK_OK) aclcheck_error(aclresult, OBJECT_TABLESPACE, get_tablespace_name(tablespaceId)); } /* In all cases disallow placing user relations in pg_global */ if (tablespaceId == GLOBALTABLESPACE_OID) ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("only shared relations can be placed in pg_global tablespace"))); /* Identify user ID that will own the table */ if (!OidIsValid(ownerId)) ownerId = GetUserId(); /* * Parse and validate reloptions, if any. */ reloptions = transformRelOptions((Datum) 0, stmt->options, NULL, validnsps, true, false); switch (relkind) { case RELKIND_VIEW: (void) view_reloptions(reloptions, true); break; case RELKIND_PARTITIONED_TABLE: (void) partitioned_table_reloptions(reloptions, true); break; default: (void) heap_reloptions(relkind, reloptions, true); } if (stmt->ofTypename) { AclResult aclresult; ofTypeId = typenameTypeId(NULL, stmt->ofTypename); aclresult = object_aclcheck(TypeRelationId, ofTypeId, GetUserId(), ACL_USAGE); if (aclresult != ACLCHECK_OK) aclcheck_error_type(aclresult, ofTypeId); } else ofTypeId = InvalidOid; /* * Look up inheritance ancestors and generate relation schema, including * inherited attributes. (Note that stmt->tableElts is destructively * modified by MergeAttributes.) */ stmt->tableElts = MergeAttributes(stmt->tableElts, inheritOids, stmt->relation->relpersistence, stmt->partbound != NULL, &old_constraints, &old_notnulls); /* * NB: The defaults and constraints we just inherited are already cooked, * so they don't get the USAGE checks that AddRelationNewConstraints() * applies to raw ones. That's intentional: the parent's own catalog * entries already depend on those types, so copying them pins nothing * new, and creating a child requires owning the parent, anyway. */ /* * Create a tuple descriptor from the relation schema. Note that this * deals with column names, types, and in-descriptor NOT NULL flags, but * not default values, NOT NULL or CHECK constraints; we handle those * below. */ descriptor = BuildDescForRelation(stmt->tableElts); /* * Find columns with default values and prepare for insertion of the * defaults. Pre-cooked (that is, inherited) defaults go into a list of * CookedConstraint structs that we'll pass to heap_create_with_catalog, * while raw defaults go into a list of RawColumnDefault structs that will * be processed by AddRelationNewConstraints. (We can't deal with raw * expressions until we can do transformExpr.) */ rawDefaults = NIL; cookedDefaults = NIL; attnum = 0; foreach(listptr, stmt->tableElts) { ColumnDef *colDef = lfirst(listptr); attnum++; if (colDef->raw_default != NULL) { RawColumnDefault *rawEnt; Assert(colDef->cooked_default == NULL); rawEnt = palloc_object(RawColumnDefault); rawEnt->attnum = attnum; rawEnt->raw_default = colDef->raw_default; rawEnt->generated = colDef->generated; rawDefaults = lappend(rawDefaults, rawEnt); } else if (colDef->cooked_default != NULL) { CookedConstraint *cooked; cooked = palloc_object(CookedConstraint); cooked->contype = CONSTR_DEFAULT; cooked->conoid = InvalidOid; /* until created */ cooked->name = NULL; cooked->attnum = attnum; cooked->expr = colDef->cooked_default; cooked->is_enforced = true; cooked->skip_validation = false; cooked->is_local = true; /* not used for defaults */ cooked->inhcount = 0; /* ditto */ cooked->is_no_inherit = false; cookedDefaults = lappend(cookedDefaults, cooked); } } TupleDescFinalize(descriptor); /* * For relations with table AM and partitioned tables, select access * method to use: an explicitly indicated one, or (in the case of a * partitioned table) the parent's, if it has one. */ if (stmt->accessMethod != NULL) { Assert(RELKIND_HAS_TABLE_AM(relkind) || relkind == RELKIND_PARTITIONED_TABLE); accessMethodId = get_table_am_oid(stmt->accessMethod, false); } else if (RELKIND_HAS_TABLE_AM(relkind) || relkind == RELKIND_PARTITIONED_TABLE) { if (stmt->partbound) { Assert(list_length(inheritOids) == 1); accessMethodId = get_rel_relam(linitial_oid(inheritOids)); } if (RELKIND_HAS_TABLE_AM(relkind) && !OidIsValid(accessMethodId)) accessMethodId = get_table_am_oid(default_table_access_method, false); } /* * Create the relation. Inherited defaults and CHECK constraints are * passed in for immediate handling --- since they don't need parsing, * they can be stored immediately. */ relationId = heap_create_with_catalog(relname, namespaceId, tablespaceId, InvalidOid, InvalidOid, ofTypeId, ownerId, accessMethodId, descriptor, list_concat(cookedDefaults, old_constraints), relkind, stmt->relation->relpersistence, false, false, stmt->oncommit, reloptions, true, allowSystemTableMods, false, InvalidOid, typaddress); /* * We must bump the command counter to make the newly-created relation * tuple visible for opening. */ CommandCounterIncrement(); /* * Open the new relation and acquire exclusive lock on it. This isn't * really necessary for locking out other backends (since they can't see * the new rel anyway until we commit), but it keeps the lock manager from * complaining about deadlock risks. */ rel = relation_open(relationId, AccessExclusiveLock); /* * Now add any newly specified column default and generation expressions * to the new relation. These are passed to us in the form of raw * parsetrees; we need to transform them to executable expression trees * before they can be added. The most convenient way to do that is to * apply the parser's transformExpr routine, but transformExpr doesn't * work unless we have a pre-existing relation. So, the transformation has * to be postponed to this final step of CREATE TABLE. * * This needs to be before processing the partitioning clauses because * those could refer to generated columns. */ if (rawDefaults) AddRelationNewConstraints(rel, rawDefaults, NIL, true, true, false, queryString); /* * Make column generation expressions visible for use by partitioning. */ CommandCounterIncrement(); /* Process and store partition bound, if any. */ if (stmt->partbound) { PartitionBoundSpec *bound; ParseState *pstate; Oid parentId = linitial_oid(inheritOids), defaultPartOid; Relation parent, defaultRel = NULL; ParseNamespaceItem *nsitem; /* Already have strong enough lock on the parent */ parent = table_open(parentId, NoLock); /* * We are going to try to validate the partition bound specification * against the partition key of parentRel, so it better have one. */ if (parent->rd_rel->relkind != RELKIND_PARTITIONED_TABLE) ereport(ERROR, (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), errmsg("\"%s\" is not partitioned", RelationGetRelationName(parent)))); /* * The partition constraint of the default partition depends on the * partition bounds of every other partition. It is possible that * another backend might be about to execute a query on the default * partition table, and that the query relies on previously cached * default partition constraints. We must therefore take a table lock * strong enough to prevent all queries on the default partition from * proceeding until we commit and send out a shared-cache-inval notice * that will make them update their index lists. * * Order of locking: The relation being added won't be visible to * other backends until it is committed, hence here in * DefineRelation() the order of locking the default partition and the * relation being added does not matter. But at all other places we * need to lock the default relation before we lock the relation being * added or removed i.e. we should take the lock in same order at all * the places such that lock parent, lock default partition and then * lock the partition so as to avoid a deadlock. */ defaultPartOid = get_default_oid_from_partdesc(RelationGetPartitionDesc(parent, true)); if (OidIsValid(defaultPartOid)) defaultRel = table_open(defaultPartOid, AccessExclusiveLock); /* Transform the bound values */ pstate = make_parsestate(NULL); pstate->p_sourcetext = queryString; /* * Add an nsitem containing this relation, so that transformExpr * called on partition bound expressions is able to report errors * using a proper context. */ nsitem = addRangeTableEntryForRelation(pstate, rel, AccessShareLock, NULL, false, false); addNSItemToQuery(pstate, nsitem, false, true, true); bound = transformPartitionBound(pstate, parent, stmt->partbound); /* * Check first that the new partition's bound is valid and does not * overlap with any of existing partitions of the parent. */ check_new_partition_bound(relname, parent, bound, pstate); /* * If the default partition exists, its partition constraints will * change after the addition of this new partition such that it won't * allow any row that qualifies for this new partition. So, check that * the existing data in the default partition satisfies the constraint * as it will exist after adding this partition. */ if (OidIsValid(defaultPartOid)) { check_default_partition_contents(parent, defaultRel, bound); /* Keep the lock until commit. */ table_close(defaultRel, NoLock); } /* Update the pg_class entry. */ StorePartitionBound(rel, parent, bound); table_close(parent, NoLock); } /* Store inheritance information for new rel. */ StoreCatalogInheritance(relationId, inheritOids, stmt->partbound != NULL); /* * Process the partitioning specification (if any) and store the partition * key information into the catalog. */ if (partitioned) { ParseState *pstate; int partnatts; AttrNumber partattrs[PARTITION_MAX_KEYS]; Oid partopclass[PARTITION_MAX_KEYS]; Oid partcollation[PARTITION_MAX_KEYS]; List *partexprs = NIL; pstate = make_parsestate(NULL); pstate->p_sourcetext = queryString; partnatts = list_length(stmt->partspec->partParams); /* Protect fixed-size arrays here and in executor */ if (partnatts > PARTITION_MAX_KEYS) ereport(ERROR, (errcode(ERRCODE_TOO_MANY_COLUMNS), errmsg("cannot partition using more than %d columns", PARTITION_MAX_KEYS))); /* * We need to transform the raw parsetrees corresponding to partition * expressions into executable expression trees. Like column defaults * and CHECK constraints, we could not have done the transformation * earlier. */ stmt->partspec = transformPartitionSpec(rel, stmt->partspec); ComputePartitionAttrs(pstate, rel, stmt->partspec->partParams, partattrs, &partexprs, partopclass, partcollation, stmt->partspec->strategy); StorePartitionKey(rel, stmt->partspec->strategy, partnatts, partattrs, partexprs, partopclass, partcollation); /* make it all visible */ CommandCounterIncrement(); } /* * If we're creating a partition, create now all the indexes, triggers, * FKs defined in the parent. * * We can't do it earlier, because DefineIndex wants to know the partition * key which we just stored. */ if (stmt->partbound) { Oid parentId = linitial_oid(inheritOids); Relation parent; List *idxlist; ListCell *cell; /* Already have strong enough lock on the parent */ parent = table_open(parentId, NoLock); idxlist = RelationGetIndexList(parent); /* * For each index in the parent table, create one in the partition */ foreach(cell, idxlist) { Relation idxRel = index_open(lfirst_oid(cell), AccessShareLock); AttrMap *attmap; IndexStmt *idxstmt; Oid constraintOid; if (rel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) { if (idxRel->rd_index->indisunique) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot create foreign partition of partitioned table \"%s\"", RelationGetRelationName(parent)), errdetail("Table \"%s\" contains indexes that are unique.", RelationGetRelationName(parent)))); else { index_close(idxRel, AccessShareLock); continue; } } attmap = build_attrmap_by_name(RelationGetDescr(rel), RelationGetDescr(parent), false); idxstmt = generateClonedIndexStmt(NULL, idxRel, attmap, &constraintOid); DefineIndex(NULL, RelationGetRelid(rel), idxstmt, InvalidOid, RelationGetRelid(idxRel), constraintOid, -1, false, false, false, false, false); index_close(idxRel, AccessShareLock); } list_free(idxlist); /* * If there are any row-level triggers, clone them to the new * partition. */ if (parent->trigdesc != NULL) CloneRowTriggersToPartition(parent, rel); /* * And foreign keys too. Note that because we're freshly creating the * table, there is no need to verify these new constraints. */ CloneForeignKeyConstraints(NULL, parent, rel); table_close(parent, NoLock); } /* * Now add any newly specified CHECK constraints to the new relation. Same * as for defaults above, but these need to come after partitioning is set * up. We save the constraint names that were used, to avoid dupes below. */ if (stmt->constraints) { List *conlist; conlist = AddRelationNewConstraints(rel, NIL, stmt->constraints, true, true, false, queryString); foreach_ptr(CookedConstraint, cons, conlist) { if (cons->name != NULL) connames = lappend(connames, cons->name); } } /* * Finally, merge the not-null constraints that are declared directly with * those that come from parent relations (making sure to count inheritance * appropriately for each), create them, and set the attnotnull flag on * columns that don't yet have it. */ nncols = AddRelationNotNullConstraints(rel, stmt->nnconstraints, old_notnulls, connames); foreach_int(attrnum, nncols) set_attnotnull(NULL, rel, attrnum, false); ObjectAddressSet(address, RelationRelationId, relationId); /* * Clean up. We keep lock on new relation (although it shouldn't be * visible to anyone else anyway, until commit). */ relation_close(rel, NoLock); return address; } /* * BuildDescForRelation * * Given a list of ColumnDef nodes, build a TupleDesc. * * Note: This is only for the limited purpose of table and view creation. Not * everything is filled in. A real tuple descriptor should be obtained from * the relcache. */ TupleDesc BuildDescForRelation(const List *columns) { int natts; AttrNumber attnum; ListCell *l; TupleDesc desc; char *attname; Oid atttypid; int32 atttypmod; Oid attcollation; int attdim; /* * allocate a new tuple descriptor */ natts = list_length(columns); desc = CreateTemplateTupleDesc(natts); attnum = 0; foreach(l, columns) { ColumnDef *entry = lfirst(l); AclResult aclresult; Form_pg_attribute att; /* * for each entry in the list, get the name and type information from * the list and have TupleDescInitEntry fill in the attribute * information we need. */ attnum++; attname = entry->colname; typenameTypeIdAndMod(NULL, entry->typeName, &atttypid, &atttypmod); aclresult = object_aclcheck(TypeRelationId, atttypid, GetUserId(), ACL_USAGE); if (aclresult != ACLCHECK_OK) aclcheck_error_type(aclresult, atttypid); attcollation = GetColumnDefCollation(NULL, entry, atttypid); attdim = list_length(entry->typeName->arrayBounds); if (attdim > PG_INT16_MAX) ereport(ERROR, errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED), errmsg("too many array dimensions")); if (entry->typeName->setof) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("column \"%s\" cannot be declared SETOF", attname))); TupleDescInitEntry(desc, attnum, attname, atttypid, atttypmod, attdim); att = TupleDescAttr(desc, attnum - 1); /* Override TupleDescInitEntry's settings as requested */ TupleDescInitEntryCollation(desc, attnum, attcollation); /* Fill in additional stuff not handled by TupleDescInitEntry */ att->attnotnull = entry->is_not_null; att->attislocal = entry->is_local; att->attinhcount = entry->inhcount; att->attidentity = entry->identity; att->attgenerated = entry->generated; att->attcompression = GetAttributeCompression(att->atttypid, entry->compression); if (entry->storage) att->attstorage = entry->storage; else if (entry->storage_name) att->attstorage = GetAttributeStorage(att->atttypid, entry->storage_name); populate_compact_attribute(desc, attnum - 1); } TupleDescFinalize(desc); return desc; } /* * Emit the right error or warning message for a "DROP" command issued on a * non-existent relation */ static void DropErrorMsgNonExistent(RangeVar *rel, char rightkind, bool missing_ok) { const struct dropmsgstrings *rentry; if (rel->schemaname != NULL && !OidIsValid(LookupNamespaceNoError(rel->schemaname))) { if (!missing_ok) { ereport(ERROR, (errcode(ERRCODE_UNDEFINED_SCHEMA), errmsg("schema \"%s\" does not exist", rel->schemaname))); } else { ereport(NOTICE, (errmsg("schema \"%s\" does not exist, skipping", rel->schemaname))); } return; } for (rentry = dropmsgstringarray; rentry->kind != '\0'; rentry++) { if (rentry->kind == rightkind) { if (!missing_ok) { ereport(ERROR, (errcode(rentry->nonexistent_code), errmsg(rentry->nonexistent_msg, rel->relname))); } else { ereport(NOTICE, (errmsg(rentry->skipping_msg, rel->relname))); break; } } } Assert(rentry->kind != '\0'); /* Should be impossible */ } /* * Emit the right error message for a "DROP" command issued on a * relation of the wrong type */ static void DropErrorMsgWrongType(const char *relname, char wrongkind, char rightkind) { const struct dropmsgstrings *rentry; const struct dropmsgstrings *wentry; for (rentry = dropmsgstringarray; rentry->kind != '\0'; rentry++) if (rentry->kind == rightkind) break; Assert(rentry->kind != '\0'); for (wentry = dropmsgstringarray; wentry->kind != '\0'; wentry++) if (wentry->kind == wrongkind) break; /* wrongkind could be something we don't have in our table... */ ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg(rentry->nota_msg, relname), (wentry->kind != '\0') ? errhint("%s", _(wentry->drophint_msg)) : 0)); } /* * RemoveRelations * Implements DROP TABLE, DROP INDEX, DROP SEQUENCE, DROP VIEW, * DROP MATERIALIZED VIEW, DROP FOREIGN TABLE, DROP PROPERTY GRAPH */ void RemoveRelations(DropStmt *drop) { ObjectAddresses *objects; char relkind; ListCell *cell; int flags = 0; LOCKMODE lockmode = AccessExclusiveLock; /* DROP CONCURRENTLY uses a weaker lock, and has some restrictions */ if (drop->concurrent) { /* * Note that for temporary relations this lock may get upgraded later * on, but as no other session can access a temporary relation, this * is actually fine. */ lockmode = ShareUpdateExclusiveLock; Assert(drop->removeType == OBJECT_INDEX); if (list_length(drop->objects) != 1) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("DROP INDEX CONCURRENTLY does not support dropping multiple objects"))); if (drop->behavior == DROP_CASCADE) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("DROP INDEX CONCURRENTLY does not support CASCADE"))); } /* * First we identify all the relations, then we delete them in a single * performMultipleDeletions() call. This is to avoid unwanted DROP * RESTRICT errors if one of the relations depends on another. */ /* Determine required relkind */ switch (drop->removeType) { case OBJECT_TABLE: relkind = RELKIND_RELATION; break; case OBJECT_INDEX: relkind = RELKIND_INDEX; break; case OBJECT_SEQUENCE: relkind = RELKIND_SEQUENCE; break; case OBJECT_VIEW: relkind = RELKIND_VIEW; break; case OBJECT_MATVIEW: relkind = RELKIND_MATVIEW; break; case OBJECT_FOREIGN_TABLE: relkind = RELKIND_FOREIGN_TABLE; break; case OBJECT_PROPGRAPH: relkind = RELKIND_PROPGRAPH; break; default: elog(ERROR, "unrecognized drop object type: %d", (int) drop->removeType); relkind = 0; /* keep compiler quiet */ break; } /* Lock and validate each relation; build a list of object addresses */ objects = new_object_addresses(); foreach(cell, drop->objects) { RangeVar *rel = makeRangeVarFromNameList((List *) lfirst(cell)); Oid relOid; ObjectAddress obj; struct DropRelationCallbackState state; /* * These next few steps are a great deal like relation_openrv, but we * don't bother building a relcache entry since we don't need it. * * Check for shared-cache-inval messages before trying to access the * relation. This is needed to cover the case where the name * identifies a rel that has been dropped and recreated since the * start of our transaction: if we don't flush the old syscache entry, * then we'll latch onto that entry and suffer an error later. */ AcceptInvalidationMessages(); /* Look up the appropriate relation using namespace search. */ state.expected_relkind = relkind; state.heap_lockmode = drop->concurrent ? ShareUpdateExclusiveLock : AccessExclusiveLock; /* We must initialize these fields to show that no locks are held: */ state.heapOid = InvalidOid; state.partParentOid = InvalidOid; relOid = RangeVarGetRelidExtended(rel, lockmode, RVR_MISSING_OK, RangeVarCallbackForDropRelation, &state); /* Not there? */ if (!OidIsValid(relOid)) { DropErrorMsgNonExistent(rel, relkind, drop->missing_ok); continue; } /* * Decide if concurrent mode needs to be used here or not. The * callback retrieved the rel's persistence for us. */ if (drop->concurrent && state.actual_relpersistence != RELPERSISTENCE_TEMP) { Assert(list_length(drop->objects) == 1 && drop->removeType == OBJECT_INDEX); flags |= PERFORM_DELETION_CONCURRENTLY; } /* * Concurrent index drop cannot be used with partitioned indexes, * either. */ if ((flags & PERFORM_DELETION_CONCURRENTLY) != 0 && state.actual_relkind == RELKIND_PARTITIONED_INDEX) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot drop partitioned index \"%s\" concurrently", rel->relname))); /* * If we're told to drop a partitioned index, we must acquire lock on * all the children of its parent partitioned table before proceeding. * Otherwise we'd try to lock the child index partitions before their * tables, leading to potential deadlock against other sessions that * will lock those objects in the other order. */ if (state.actual_relkind == RELKIND_PARTITIONED_INDEX) (void) find_all_inheritors(state.heapOid, state.heap_lockmode, NULL); /* OK, we're ready to delete this one */ obj.classId = RelationRelationId; obj.objectId = relOid; obj.objectSubId = 0; add_exact_object_address(&obj, objects); } performMultipleDeletions(objects, drop->behavior, flags); free_object_addresses(objects); } /* * Before acquiring a table lock, check whether we have sufficient rights. * In the case of DROP INDEX, also try to lock the table before the index. * Also, if the table to be dropped is a partition, we try to lock the parent * first. */ static void RangeVarCallbackForDropRelation(const RangeVar *rel, Oid relOid, Oid oldRelOid, void *arg) { HeapTuple tuple; struct DropRelationCallbackState *state; char expected_relkind; bool is_partition; Form_pg_class classform; LOCKMODE heap_lockmode; bool invalid_system_index = false; state = (struct DropRelationCallbackState *) arg; heap_lockmode = state->heap_lockmode; /* * If we previously locked some other index's heap, and the name we're * looking up no longer refers to that relation, release the now-useless * lock. */ if (relOid != oldRelOid && OidIsValid(state->heapOid)) { UnlockRelationOid(state->heapOid, heap_lockmode); state->heapOid = InvalidOid; } /* * Similarly, if we previously locked some other partition's heap, and the * name we're looking up no longer refers to that relation, release the * now-useless lock. */ if (relOid != oldRelOid && OidIsValid(state->partParentOid)) { UnlockRelationOid(state->partParentOid, AccessExclusiveLock); state->partParentOid = InvalidOid; } /* Didn't find a relation, so no need for locking or permission checks. */ if (!OidIsValid(relOid)) return; tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relOid)); if (!HeapTupleIsValid(tuple)) return; /* concurrently dropped, so nothing to do */ classform = (Form_pg_class) GETSTRUCT(tuple); is_partition = classform->relispartition; /* Pass back some data to save lookups in RemoveRelations */ state->actual_relkind = classform->relkind; state->actual_relpersistence = classform->relpersistence; /* * Both RELKIND_RELATION and RELKIND_PARTITIONED_TABLE are OBJECT_TABLE, * but RemoveRelations() can only pass one relkind for a given relation. * It chooses RELKIND_RELATION for both regular and partitioned tables. * That means we must be careful before giving the wrong type error when * the relation is RELKIND_PARTITIONED_TABLE. An equivalent problem * exists with indexes. */ if (classform->relkind == RELKIND_PARTITIONED_TABLE) expected_relkind = RELKIND_RELATION; else if (classform->relkind == RELKIND_PARTITIONED_INDEX) expected_relkind = RELKIND_INDEX; else expected_relkind = classform->relkind; if (state->expected_relkind != expected_relkind) DropErrorMsgWrongType(rel->relname, classform->relkind, state->expected_relkind); /* Allow DROP to either table owner or schema owner */ if (!object_ownercheck(RelationRelationId, relOid, GetUserId()) && !object_ownercheck(NamespaceRelationId, classform->relnamespace, GetUserId())) aclcheck_error(ACLCHECK_NOT_OWNER, get_relkind_objtype(classform->relkind), rel->relname); /* * Check the case of a system index that might have been invalidated by a * failed concurrent process and allow its drop. For the time being, this * only concerns indexes of toast relations that became invalid during a * REINDEX CONCURRENTLY process. */ if (IsSystemClass(relOid, classform) && classform->relkind == RELKIND_INDEX) { HeapTuple locTuple; Form_pg_index indexform; bool indisvalid; locTuple = SearchSysCache1(INDEXRELID, ObjectIdGetDatum(relOid)); if (!HeapTupleIsValid(locTuple)) { ReleaseSysCache(tuple); return; } indexform = (Form_pg_index) GETSTRUCT(locTuple); indisvalid = indexform->indisvalid; ReleaseSysCache(locTuple); /* Mark object as being an invalid index of system catalogs */ if (!indisvalid) invalid_system_index = true; } /* In the case of an invalid index, it is fine to bypass this check */ if (!invalid_system_index && !allowSystemTableMods && IsSystemClass(relOid, classform)) ereport(ERROR, (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), errmsg("permission denied: \"%s\" is a system catalog", rel->relname))); ReleaseSysCache(tuple); /* * In DROP INDEX, attempt to acquire lock on the parent table before * locking the index. index_drop() will need this anyway, and since * regular queries lock tables before their indexes, we risk deadlock if * we do it the other way around. No error if we don't find a pg_index * entry, though --- the relation may have been dropped. Note that this * code will execute for either plain or partitioned indexes. */ if (expected_relkind == RELKIND_INDEX && relOid != oldRelOid) { state->heapOid = IndexGetRelation(relOid, true); if (OidIsValid(state->heapOid)) LockRelationOid(state->heapOid, heap_lockmode); } /* * Similarly, if the relation is a partition, we must acquire lock on its * parent before locking the partition. That's because queries lock the * parent before its partitions, so we risk deadlock if we do it the other * way around. */ if (is_partition && relOid != oldRelOid) { state->partParentOid = get_partition_parent(relOid, true); if (OidIsValid(state->partParentOid)) LockRelationOid(state->partParentOid, AccessExclusiveLock); } } /* * ExecuteTruncate * Executes a TRUNCATE command. * * This is a multi-relation truncate. We first open and grab exclusive * lock on all relations involved, checking permissions and otherwise * verifying that the relation is OK for truncation. Note that if relations * are foreign tables, at this stage, we have not yet checked that their * foreign data in external data sources are OK for truncation. These are * checked when foreign data are actually truncated later. In CASCADE mode, * relations having FK references to the targeted relations are automatically * added to the group; in RESTRICT mode, we check that all FK references are * internal to the group that's being truncated. Finally all the relations * are truncated and reindexed. */ void ExecuteTruncate(TruncateStmt *stmt) { List *rels = NIL; List *relids = NIL; List *relids_logged = NIL; ListCell *cell; /* * Open, exclusive-lock, and check all the explicitly-specified relations */ foreach(cell, stmt->relations) { RangeVar *rv = lfirst(cell); Relation rel; bool recurse = rv->inh; Oid myrelid; LOCKMODE lockmode = AccessExclusiveLock; myrelid = RangeVarGetRelidExtended(rv, lockmode, 0, RangeVarCallbackForTruncate, NULL); /* don't throw error for "TRUNCATE foo, foo" */ if (list_member_oid(relids, myrelid)) continue; /* open the relation, we already hold a lock on it */ rel = table_open(myrelid, NoLock); /* * RangeVarGetRelidExtended() has done most checks with its callback, * but other checks with the now-opened Relation remain. */ truncate_check_activity(rel); rels = lappend(rels, rel); relids = lappend_oid(relids, myrelid); /* Log this relation only if needed for logical decoding */ if (RelationIsLogicallyLogged(rel)) relids_logged = lappend_oid(relids_logged, myrelid); if (recurse) { ListCell *child; List *children; children = find_all_inheritors(myrelid, lockmode, NULL); foreach(child, children) { Oid childrelid = lfirst_oid(child); if (list_member_oid(relids, childrelid)) continue; /* find_all_inheritors already got lock */ rel = table_open(childrelid, NoLock); /* * It is possible that the parent table has children that are * temp tables of other backends. We cannot safely access * such tables (because of buffering issues), and the best * thing to do is to silently ignore them. Note that this * check is the same as one of the checks done in * truncate_check_activity() called below, still it is kept * here for simplicity. */ if (RELATION_IS_OTHER_TEMP(rel)) { table_close(rel, lockmode); continue; } /* * Inherited TRUNCATE commands perform access permission * checks on the parent table only. So we skip checking the * children's permissions and don't call * truncate_check_perms() here. */ truncate_check_rel(RelationGetRelid(rel), rel->rd_rel); truncate_check_activity(rel); rels = lappend(rels, rel); relids = lappend_oid(relids, childrelid); /* Log this relation only if needed for logical decoding */ if (RelationIsLogicallyLogged(rel)) relids_logged = lappend_oid(relids_logged, childrelid); } } else if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot truncate only a partitioned table"), errhint("Do not specify the ONLY keyword, or use TRUNCATE ONLY on the partitions directly."))); } ExecuteTruncateGuts(rels, relids, relids_logged, stmt->behavior, stmt->restart_seqs, false); /* And close the rels */ foreach(cell, rels) { Relation rel = (Relation) lfirst(cell); table_close(rel, NoLock); } } /* * ExecuteTruncateGuts * * Internal implementation of TRUNCATE. This is called by the actual TRUNCATE * command (see above) as well as replication subscribers that execute a * replicated TRUNCATE action. * * explicit_rels is the list of Relations to truncate that the command * specified. relids is the list of Oids corresponding to explicit_rels. * relids_logged is the list of Oids (a subset of relids) that require * WAL-logging. This is all a bit redundant, but the existing callers have * this information handy in this form. */ void ExecuteTruncateGuts(List *explicit_rels, List *relids, List *relids_logged, DropBehavior behavior, bool restart_seqs, bool run_as_table_owner) { List *rels; List *seq_relids = NIL; HTAB *ft_htab = NULL; EState *estate; ResultRelInfo *resultRelInfos; ResultRelInfo *resultRelInfo; SubTransactionId mySubid; ListCell *cell; Oid *logrelids; /* * Check the explicitly-specified relations. * * In CASCADE mode, suck in all referencing relations as well. This * requires multiple iterations to find indirectly-dependent relations. At * each phase, we need to exclusive-lock new rels before looking for their * dependencies, else we might miss something. Also, we check each rel as * soon as we open it, to avoid a faux pas such as holding lock for a long * time on a rel we have no permissions for. */ rels = list_copy(explicit_rels); if (behavior == DROP_CASCADE) { for (;;) { List *newrelids; newrelids = heap_truncate_find_FKs(relids); if (newrelids == NIL) break; /* nothing else to add */ foreach(cell, newrelids) { Oid relid = lfirst_oid(cell); Relation rel; rel = table_open(relid, AccessExclusiveLock); ereport(NOTICE, (errmsg("truncate cascades to table \"%s\"", RelationGetRelationName(rel)))); truncate_check_rel(relid, rel->rd_rel); truncate_check_perms(relid, rel->rd_rel); truncate_check_activity(rel); rels = lappend(rels, rel); relids = lappend_oid(relids, relid); /* Log this relation only if needed for logical decoding */ if (RelationIsLogicallyLogged(rel)) relids_logged = lappend_oid(relids_logged, relid); } } } /* * Check foreign key references. In CASCADE mode, this should be * unnecessary since we just pulled in all the references; but as a * cross-check, do it anyway if in an Assert-enabled build. */ #ifdef USE_ASSERT_CHECKING heap_truncate_check_FKs(rels, false); #else if (behavior == DROP_RESTRICT) heap_truncate_check_FKs(rels, false); #endif /* * If we are asked to restart sequences, find all the sequences, lock them * (we need AccessExclusiveLock for ResetSequence), and check permissions. * We want to do this early since it's pointless to do all the truncation * work only to fail on sequence permissions. */ if (restart_seqs) { foreach(cell, rels) { Relation rel = (Relation) lfirst(cell); List *seqlist = getOwnedSequences(RelationGetRelid(rel)); ListCell *seqcell; foreach(seqcell, seqlist) { Oid seq_relid = lfirst_oid(seqcell); Relation seq_rel; seq_rel = relation_open(seq_relid, AccessExclusiveLock); /* This check must match AlterSequence! */ if (!object_ownercheck(RelationRelationId, seq_relid, GetUserId())) aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SEQUENCE, RelationGetRelationName(seq_rel)); seq_relids = lappend_oid(seq_relids, seq_relid); relation_close(seq_rel, NoLock); } } } /* Prepare to catch AFTER triggers. */ AfterTriggerBeginQuery(); /* * To fire triggers, we'll need an EState as well as a ResultRelInfo for * each relation. We don't need to call ExecOpenIndices, though. * * We put the ResultRelInfos in the es_opened_result_relations list, even * though we don't have a range table and don't populate the * es_result_relations array. That's a bit bogus, but it's enough to make * ExecGetTriggerResultRel() find them. */ estate = CreateExecutorState(); resultRelInfos = (ResultRelInfo *) palloc(list_length(rels) * sizeof(ResultRelInfo)); resultRelInfo = resultRelInfos; foreach(cell, rels) { Relation rel = (Relation) lfirst(cell); InitResultRelInfo(resultRelInfo, rel, 0, /* dummy rangetable index */ NULL, 0); estate->es_opened_result_relations = lappend(estate->es_opened_result_relations, resultRelInfo); resultRelInfo++; } /* * Process all BEFORE STATEMENT TRUNCATE triggers before we begin * truncating (this is because one of them might throw an error). Also, if * we were to allow them to prevent statement execution, that would need * to be handled here. */ resultRelInfo = resultRelInfos; foreach(cell, rels) { UserContext ucxt; if (run_as_table_owner) SwitchToUntrustedUser(resultRelInfo->ri_RelationDesc->rd_rel->relowner, &ucxt); ExecBSTruncateTriggers(estate, resultRelInfo); if (run_as_table_owner) RestoreUserContext(&ucxt); resultRelInfo++; } /* * OK, truncate each table. */ mySubid = GetCurrentSubTransactionId(); foreach(cell, rels) { Relation rel = (Relation) lfirst(cell); /* Skip partitioned tables as there is nothing to do */ if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) continue; /* * Build the lists of foreign tables belonging to each foreign server * and pass each list to the foreign data wrapper's callback function, * so that each server can truncate its all foreign tables in bulk. * Each list is saved as a single entry in a hash table that uses the * server OID as lookup key. */ if (rel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) { Oid serverid = GetForeignServerIdByRelId(RelationGetRelid(rel)); bool found; ForeignTruncateInfo *ft_info; /* First time through, initialize hashtable for foreign tables */ if (!ft_htab) { HASHCTL hctl; memset(&hctl, 0, sizeof(HASHCTL)); hctl.keysize = sizeof(Oid); hctl.entrysize = sizeof(ForeignTruncateInfo); hctl.hcxt = CurrentMemoryContext; ft_htab = hash_create("TRUNCATE for Foreign Tables", 32, /* start small and extend */ &hctl, HASH_ELEM | HASH_BLOBS | HASH_CONTEXT); } /* Find or create cached entry for the foreign table */ ft_info = hash_search(ft_htab, &serverid, HASH_ENTER, &found); if (!found) ft_info->rels = NIL; /* * Save the foreign table in the entry of the server that the * foreign table belongs to. */ ft_info->rels = lappend(ft_info->rels, rel); continue; } /* * Normally, we need a transaction-safe truncation here. However, if * the table was either created in the current (sub)transaction or has * a new relfilenumber in the current (sub)transaction, then we can * just truncate it in-place, because a rollback would cause the whole * table or the current physical file to be thrown away anyway. */ if (rel->rd_createSubid == mySubid || rel->rd_newRelfilelocatorSubid == mySubid) { /* Immediate, non-rollbackable truncation is OK */ heap_truncate_one_rel(rel); } else { Oid heap_relid; Oid toast_relid; ReindexParams reindex_params = {0}; /* * This effectively deletes all rows in the table, and may be done * in a serializable transaction. In that case we must record a * rw-conflict in to this transaction from each transaction * holding a predicate lock on the table. */ CheckTableForSerializableConflictIn(rel); /* * Need the full transaction-safe pushups. * * Create a new empty storage file for the relation, and assign it * as the relfilenumber value. The old storage file is scheduled * for deletion at commit. */ RelationSetNewRelfilenumber(rel, rel->rd_rel->relpersistence); heap_relid = RelationGetRelid(rel); /* * The same for the toast table, if any. */ toast_relid = rel->rd_rel->reltoastrelid; if (OidIsValid(toast_relid)) { Relation toastrel = relation_open(toast_relid, AccessExclusiveLock); RelationSetNewRelfilenumber(toastrel, toastrel->rd_rel->relpersistence); table_close(toastrel, NoLock); } /* * Reconstruct the indexes to match, and we're done. */ reindex_relation(NULL, heap_relid, REINDEX_REL_PROCESS_TOAST, &reindex_params); } pgstat_count_truncate(rel); } /* Now go through the hash table, and truncate foreign tables */ if (ft_htab) { ForeignTruncateInfo *ft_info; HASH_SEQ_STATUS seq; hash_seq_init(&seq, ft_htab); PG_TRY(); { while ((ft_info = hash_seq_search(&seq)) != NULL) { FdwRoutine *routine = GetFdwRoutineByServerId(ft_info->serverid); /* truncate_check_rel() has checked that already */ Assert(routine->ExecForeignTruncate != NULL); routine->ExecForeignTruncate(ft_info->rels, behavior, restart_seqs); } } PG_FINALLY(); { hash_destroy(ft_htab); } PG_END_TRY(); } /* * Restart owned sequences if we were asked to. */ foreach(cell, seq_relids) { Oid seq_relid = lfirst_oid(cell); ResetSequence(seq_relid); } /* * Write a WAL record to allow this set of actions to be logically * decoded. * * Assemble an array of relids so we can write a single WAL record for the * whole action. */ if (relids_logged != NIL) { xl_heap_truncate xlrec; int i = 0; /* should only get here if effective_wal_level is 'logical' */ Assert(XLogLogicalInfoActive()); logrelids = palloc(list_length(relids_logged) * sizeof(Oid)); foreach(cell, relids_logged) logrelids[i++] = lfirst_oid(cell); xlrec.dbId = MyDatabaseId; xlrec.nrelids = list_length(relids_logged); xlrec.flags = 0; if (behavior == DROP_CASCADE) xlrec.flags |= XLH_TRUNCATE_CASCADE; if (restart_seqs) xlrec.flags |= XLH_TRUNCATE_RESTART_SEQS; XLogBeginInsert(); XLogRegisterData(&xlrec, SizeOfHeapTruncate); XLogRegisterData(logrelids, list_length(relids_logged) * sizeof(Oid)); XLogSetRecordFlags(XLOG_INCLUDE_ORIGIN); (void) XLogInsert(RM_HEAP_ID, XLOG_HEAP_TRUNCATE); } /* * Process all AFTER STATEMENT TRUNCATE triggers. */ resultRelInfo = resultRelInfos; foreach(cell, rels) { UserContext ucxt; if (run_as_table_owner) SwitchToUntrustedUser(resultRelInfo->ri_RelationDesc->rd_rel->relowner, &ucxt); ExecASTruncateTriggers(estate, resultRelInfo); if (run_as_table_owner) RestoreUserContext(&ucxt); resultRelInfo++; } /* Handle queued AFTER triggers */ AfterTriggerEndQuery(estate); /* We can clean up the EState now */ FreeExecutorState(estate); /* * Close any rels opened by CASCADE (can't do this while EState still * holds refs) */ rels = list_difference_ptr(rels, explicit_rels); foreach(cell, rels) { Relation rel = (Relation) lfirst(cell); table_close(rel, NoLock); } } /* * Check that a given relation is safe to truncate. Subroutine for * ExecuteTruncate() and RangeVarCallbackForTruncate(). */ static void truncate_check_rel(Oid relid, Form_pg_class reltuple) { char *relname = NameStr(reltuple->relname); /* * Only allow truncate on regular tables, foreign tables using foreign * data wrappers supporting TRUNCATE and partitioned tables (although, the * latter are only being included here for the following checks; no * physical truncation will occur in their case.). */ if (reltuple->relkind == RELKIND_FOREIGN_TABLE) { Oid serverid = GetForeignServerIdByRelId(relid); FdwRoutine *fdwroutine = GetFdwRoutineByServerId(serverid); if (!fdwroutine->ExecForeignTruncate) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot truncate foreign table \"%s\"", relname))); } else if (reltuple->relkind != RELKIND_RELATION && reltuple->relkind != RELKIND_PARTITIONED_TABLE) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is not a table", relname))); /* * Most system catalogs can't be truncated at all, or at least not unless * allow_system_table_mods=on. As an exception, however, we allow * pg_largeobject and pg_largeobject_metadata to be truncated as part of * pg_upgrade, because we need to change its relfilenode to match the old * cluster, and allowing a TRUNCATE command to be executed is the easiest * way of doing that. We also allow TRUNCATE on the conflict log tables, * to permit users to manually prune conflict data to manage disk space. */ if (!allowSystemTableMods && IsSystemClass(relid, reltuple) && !IsConflictLogTableClass(reltuple) && (!IsBinaryUpgrade || (relid != LargeObjectRelationId && relid != LargeObjectMetadataRelationId))) ereport(ERROR, (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), errmsg("permission denied: \"%s\" is a system catalog", relname))); InvokeObjectTruncateHook(relid); } /* * Check that current user has the permission to truncate given relation. */ static void truncate_check_perms(Oid relid, Form_pg_class reltuple) { char *relname = NameStr(reltuple->relname); AclResult aclresult; /* Permissions checks */ aclresult = pg_class_aclcheck(relid, GetUserId(), ACL_TRUNCATE); if (aclresult != ACLCHECK_OK) aclcheck_error(aclresult, get_relkind_objtype(reltuple->relkind), relname); } /* * Set of extra sanity checks to check if a given relation is safe to * truncate. This is split with truncate_check_rel() as * RangeVarCallbackForTruncate() cannot open a Relation yet. */ static void truncate_check_activity(Relation rel) { /* * Don't allow truncate on temp tables of other backends ... their local * buffer manager is not going to cope. */ if (RELATION_IS_OTHER_TEMP(rel)) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot truncate temporary tables of other sessions"))); /* * Also check for active uses of the relation in the current transaction, * including open scans and pending AFTER trigger events. */ CheckTableNotInUse(rel, "TRUNCATE"); } /* * storage_name * returns the name corresponding to a typstorage/attstorage enum value */ static const char * storage_name(char c) { switch (c) { case TYPSTORAGE_PLAIN: return "PLAIN"; case TYPSTORAGE_EXTERNAL: return "EXTERNAL"; case TYPSTORAGE_EXTENDED: return "EXTENDED"; case TYPSTORAGE_MAIN: return "MAIN"; default: return "???"; } } /*---------- * MergeAttributes * Returns new schema given initial schema and superclasses. * * Input arguments: * 'columns' is the column/attribute definition for the table. (It's a list * of ColumnDef's.) It is destructively changed. * 'supers' is a list of OIDs of parent relations, already locked by caller. * 'relpersistence' is the persistence type of the table. * 'is_partition' tells if the table is a partition. * * Output arguments: * 'supconstr' receives a list of CookedConstraint representing * CHECK constraints belonging to parent relations, updated as * necessary to be valid for the child. * 'supnotnulls' receives a list of CookedConstraint representing * not-null constraints based on those from parent relations. * * Return value: * Completed schema list. * * Notes: * The order in which the attributes are inherited is very important. * Intuitively, the inherited attributes should come first. If a table * inherits from multiple parents, the order of those attributes are * according to the order of the parents specified in CREATE TABLE. * * Here's an example: * * create table person (name text, age int4, location point); * create table emp (salary int4, manager text) inherits(person); * create table student (gpa float8) inherits (person); * create table stud_emp (percent int4) inherits (emp, student); * * The order of the attributes of stud_emp is: * * person {1:name, 2:age, 3:location} * / \ * {6:gpa} student emp {4:salary, 5:manager} * \ / * stud_emp {7:percent} * * If the same attribute name appears multiple times, then it appears * in the result table in the proper location for its first appearance. * * Constraints (including not-null constraints) for the child table * are the union of all relevant constraints, from both the child schema * and parent tables. In addition, in legacy inheritance, each column that * appears in a primary key in any of the parents also gets a NOT NULL * constraint (partitioning doesn't need this, because the PK itself gets * inherited.) * * The default value for a child column is defined as: * (1) If the child schema specifies a default, that value is used. * (2) If neither the child nor any parent specifies a default, then * the column will not have a default. * (3) If conflicting defaults are inherited from different parents * (and not overridden by the child), an error is raised. * (4) Otherwise the inherited default is used. * * Note that the default-value infrastructure is used for generated * columns' expressions too, so most of the preceding paragraph applies * to generation expressions too. We insist that a child column be * generated if and only if its parent(s) are, but it need not have * the same generation expression. *---------- */ static List * MergeAttributes(List *columns, const List *supers, char relpersistence, bool is_partition, List **supconstr, List **supnotnulls) { List *inh_columns = NIL; List *constraints = NIL; List *nnconstraints = NIL; bool have_bogus_defaults = false; int child_attno; static Node bogus_marker = {0}; /* marks conflicting defaults */ List *saved_columns = NIL; ListCell *lc; /* * Check for and reject tables with too many columns. We perform this * check relatively early for two reasons: (a) we don't run the risk of * overflowing an AttrNumber in subsequent code (b) an O(n^2) algorithm is * okay if we're processing <= 1600 columns, but could take minutes to * execute if the user attempts to create a table with hundreds of * thousands of columns. * * Note that we also need to check that we do not exceed this figure after * including columns from inherited relations. */ if (list_length(columns) > MaxHeapAttributeNumber) ereport(ERROR, (errcode(ERRCODE_TOO_MANY_COLUMNS), errmsg("tables can have at most %d columns", MaxHeapAttributeNumber))); /* * Check for duplicate names in the explicit list of attributes. * * Although we might consider merging such entries in the same way that we * handle name conflicts for inherited attributes, it seems to make more * sense to assume such conflicts are errors. * * We don't use foreach() here because we have two nested loops over the * columns list, with possible element deletions in the inner one. If we * used foreach_delete_current() it could only fix up the state of one of * the loops, so it seems cleaner to use looping over list indexes for * both loops. Note that any deletion will happen beyond where the outer * loop is, so its index never needs adjustment. */ for (int coldefpos = 0; coldefpos < list_length(columns); coldefpos++) { ColumnDef *coldef = list_nth_node(ColumnDef, columns, coldefpos); if (!is_partition && coldef->typeName == NULL) { /* * Typed table column option that does not belong to a column from * the type. This works because the columns from the type come * first in the list. (We omit this check for partition column * lists; those are processed separately below.) */ ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" does not exist", coldef->colname))); } /* restpos scans all entries beyond coldef; incr is in loop body */ for (int restpos = coldefpos + 1; restpos < list_length(columns);) { ColumnDef *restdef = list_nth_node(ColumnDef, columns, restpos); if (strcmp(coldef->colname, restdef->colname) == 0) { if (coldef->is_from_type) { /* * merge the column options into the column from the type */ coldef->is_not_null = restdef->is_not_null; coldef->raw_default = restdef->raw_default; coldef->cooked_default = restdef->cooked_default; coldef->constraints = restdef->constraints; coldef->is_from_type = false; columns = list_delete_nth_cell(columns, restpos); } else ereport(ERROR, (errcode(ERRCODE_DUPLICATE_COLUMN), errmsg("column \"%s\" specified more than once", coldef->colname))); } else restpos++; } } /* * In case of a partition, there are no new column definitions, only dummy * ColumnDefs created for column constraints. Set them aside for now and * process them at the end. */ if (is_partition) { saved_columns = columns; columns = NIL; } /* * Scan the parents left-to-right, and merge their attributes to form a * list of inherited columns (inh_columns). */ child_attno = 0; foreach(lc, supers) { Oid parent = lfirst_oid(lc); Relation relation; TupleDesc tupleDesc; TupleConstr *constr; AttrMap *newattmap; List *inherited_defaults; List *cols_with_defaults; List *nnconstrs; ListCell *lc1; ListCell *lc2; Bitmapset *nncols = NULL; /* caller already got lock */ relation = table_open(parent, NoLock); /* * Check for active uses of the parent partitioned table in the * current transaction, such as being used in some manner by an * enclosing command. */ if (is_partition) CheckTableNotInUse(relation, "CREATE TABLE .. PARTITION OF"); /* * We do not allow partitioned tables and partitions to participate in * regular inheritance. */ if (relation->rd_rel->relkind == RELKIND_PARTITIONED_TABLE && !is_partition) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot inherit from partitioned table \"%s\"", RelationGetRelationName(relation)))); if (relation->rd_rel->relispartition && !is_partition) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot inherit from partition \"%s\"", RelationGetRelationName(relation)))); /* * Conflict log tables are managed by the system for logical * replication and should not be used as parent tables, as inheritance * could interfere with the logging behavior. */ if (IsConflictLogTableNamespace(relation->rd_rel->relnamespace)) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot inherit from conflict log table \"%s\"", RelationGetRelationName(relation)), errdetail("Conflict log tables are system-managed tables for logical replication conflicts."))); if (relation->rd_rel->relkind != RELKIND_RELATION && relation->rd_rel->relkind != RELKIND_FOREIGN_TABLE && relation->rd_rel->relkind != RELKIND_PARTITIONED_TABLE) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("inherited relation \"%s\" is not a table or foreign table", RelationGetRelationName(relation)))); /* * If the parent is permanent, so must be all of its partitions. Note * that inheritance allows that case. */ if (is_partition && relation->rd_rel->relpersistence != RELPERSISTENCE_TEMP && relpersistence == RELPERSISTENCE_TEMP) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot create a temporary relation as partition of permanent relation \"%s\"", RelationGetRelationName(relation)))); /* Permanent rels cannot inherit from temporary ones */ if (relpersistence != RELPERSISTENCE_TEMP && relation->rd_rel->relpersistence == RELPERSISTENCE_TEMP) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg(!is_partition ? "cannot inherit from temporary relation \"%s\"" : "cannot create a permanent relation as partition of temporary relation \"%s\"", RelationGetRelationName(relation)))); /* If existing rel is temp, it must belong to this session */ if (RELATION_IS_OTHER_TEMP(relation)) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg(!is_partition ? "cannot inherit from temporary relation of another session" : "cannot create as partition of temporary relation of another session"))); /* * We should have an UNDER permission flag for this, but for now, * demand that creator of a child table own the parent. */ if (!object_ownercheck(RelationRelationId, RelationGetRelid(relation), GetUserId())) aclcheck_error(ACLCHECK_NOT_OWNER, get_relkind_objtype(relation->rd_rel->relkind), RelationGetRelationName(relation)); tupleDesc = RelationGetDescr(relation); constr = tupleDesc->constr; /* * newattmap->attnums[] will contain the child-table attribute numbers * for the attributes of this parent table. (They are not the same * for parents after the first one, nor if we have dropped columns.) */ newattmap = make_attrmap(tupleDesc->natts); /* We can't process inherited defaults until newattmap is complete. */ inherited_defaults = cols_with_defaults = NIL; /* * Request attnotnull on columns that have a not-null constraint * that's not marked NO INHERIT (even if not valid). */ nnconstrs = RelationGetNotNullConstraints(RelationGetRelid(relation), true, false); foreach_ptr(CookedConstraint, cc, nnconstrs) nncols = bms_add_member(nncols, cc->attnum); for (AttrNumber parent_attno = 1; parent_attno <= tupleDesc->natts; parent_attno++) { Form_pg_attribute attribute = TupleDescAttr(tupleDesc, parent_attno - 1); char *attributeName = NameStr(attribute->attname); int exist_attno; ColumnDef *newdef; ColumnDef *mergeddef; /* * Ignore dropped columns in the parent. */ if (attribute->attisdropped) continue; /* leave newattmap->attnums entry as zero */ /* * Create new column definition */ newdef = makeColumnDef(attributeName, attribute->atttypid, attribute->atttypmod, attribute->attcollation); newdef->storage = attribute->attstorage; newdef->generated = attribute->attgenerated; if (CompressionMethodIsValid(attribute->attcompression)) newdef->compression = pstrdup(GetCompressionMethodName(attribute->attcompression)); /* * Regular inheritance children are independent enough not to * inherit identity columns. But partitions are integral part of * a partitioned table and inherit identity column. */ if (is_partition) newdef->identity = attribute->attidentity; /* * Does it match some previously considered column from another * parent? */ exist_attno = findAttrByName(attributeName, inh_columns); if (exist_attno > 0) { /* * Yes, try to merge the two column definitions. */ mergeddef = MergeInheritedAttribute(inh_columns, exist_attno, newdef); newattmap->attnums[parent_attno - 1] = exist_attno; /* * Partitions have only one parent, so conflict should never * occur. */ Assert(!is_partition); } else { /* * No, create a new inherited column */ newdef->inhcount = 1; newdef->is_local = false; inh_columns = lappend(inh_columns, newdef); newattmap->attnums[parent_attno - 1] = ++child_attno; mergeddef = newdef; } /* * mark attnotnull if parent has it */ if (bms_is_member(parent_attno, nncols)) mergeddef->is_not_null = true; /* * Locate default/generation expression if any */ if (attribute->atthasdef) { Node *this_default; this_default = TupleDescGetDefault(tupleDesc, parent_attno); if (this_default == NULL) elog(ERROR, "default expression not found for attribute %d of relation \"%s\"", parent_attno, RelationGetRelationName(relation)); /* * If it's a GENERATED default, it might contain Vars that * need to be mapped to the inherited column(s)' new numbers. * We can't do that till newattmap is ready, so just remember * all the inherited default expressions for the moment. */ inherited_defaults = lappend(inherited_defaults, this_default); cols_with_defaults = lappend(cols_with_defaults, mergeddef); } } /* * Now process any inherited default expressions, adjusting attnos * using the completed newattmap map. */ forboth(lc1, inherited_defaults, lc2, cols_with_defaults) { Node *this_default = (Node *) lfirst(lc1); ColumnDef *def = (ColumnDef *) lfirst(lc2); bool found_whole_row; /* Adjust Vars to match new table's column numbering */ this_default = map_variable_attnos(this_default, 1, 0, newattmap, InvalidOid, &found_whole_row); /* * For the moment we have to reject whole-row variables. We could * convert them, if we knew the new table's rowtype OID, but that * hasn't been assigned yet. (A variable could only appear in a * generation expression, so the error message is correct.) */ if (found_whole_row) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot convert whole-row table reference"), errdetail("Generation expression for column \"%s\" contains a whole-row reference to table \"%s\".", def->colname, RelationGetRelationName(relation)))); /* * If we already had a default from some prior parent, check to * see if they are the same. If so, no problem; if not, mark the * column as having a bogus default. Below, we will complain if * the bogus default isn't overridden by the child columns. */ Assert(def->raw_default == NULL); if (def->cooked_default == NULL) def->cooked_default = this_default; else if (!equal(def->cooked_default, this_default)) { def->cooked_default = &bogus_marker; have_bogus_defaults = true; } } /* * Now copy the CHECK constraints of this parent, adjusting attnos * using the completed newattmap map. Identically named constraints * are merged if possible, else we throw error. */ if (constr && constr->num_check > 0) { ConstrCheck *check = constr->check; for (int i = 0; i < constr->num_check; i++) { char *name = check[i].ccname; Node *expr; bool found_whole_row; /* ignore if the constraint is non-inheritable */ if (check[i].ccnoinherit) continue; /* Adjust Vars to match new table's column numbering */ expr = map_variable_attnos(stringToNode(check[i].ccbin), 1, 0, newattmap, InvalidOid, &found_whole_row); /* * For the moment we have to reject whole-row variables. We * could convert them, if we knew the new table's rowtype OID, * but that hasn't been assigned yet. */ if (found_whole_row) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot convert whole-row table reference"), errdetail("Constraint \"%s\" contains a whole-row reference to table \"%s\".", name, RelationGetRelationName(relation)))); constraints = MergeCheckConstraint(constraints, name, expr, check[i].ccenforced); } } /* * Also copy the not-null constraints from this parent. The * attnotnull markings were already installed above. */ foreach_ptr(CookedConstraint, nn, nnconstrs) { Assert(nn->contype == CONSTR_NOTNULL); nn->attnum = newattmap->attnums[nn->attnum - 1]; nnconstraints = lappend(nnconstraints, nn); } free_attrmap(newattmap); /* * Close the parent rel, but keep our lock on it until xact commit. * That will prevent someone else from deleting or ALTERing the parent * before the child is committed. */ table_close(relation, NoLock); } /* * If we had no inherited attributes, the result columns are just the * explicitly declared columns. Otherwise, we need to merge the declared * columns into the inherited column list. Although, we never have any * explicitly declared columns if the table is a partition. */ if (inh_columns != NIL) { int newcol_attno = 0; foreach(lc, columns) { ColumnDef *newdef = lfirst_node(ColumnDef, lc); char *attributeName = newdef->colname; int exist_attno; /* * Partitions have only one parent and have no column definitions * of their own, so conflict should never occur. */ Assert(!is_partition); newcol_attno++; /* * Does it match some inherited column? */ exist_attno = findAttrByName(attributeName, inh_columns); if (exist_attno > 0) { /* * Yes, try to merge the two column definitions. */ MergeChildAttribute(inh_columns, exist_attno, newcol_attno, newdef); } else { /* * No, attach new column unchanged to result columns. */ inh_columns = lappend(inh_columns, newdef); } } columns = inh_columns; /* * Check that we haven't exceeded the legal # of columns after merging * in inherited columns. */ if (list_length(columns) > MaxHeapAttributeNumber) ereport(ERROR, (errcode(ERRCODE_TOO_MANY_COLUMNS), errmsg("tables can have at most %d columns", MaxHeapAttributeNumber))); } /* * Now that we have the column definition list for a partition, we can * check whether the columns referenced in the column constraint specs * actually exist. Also, merge column defaults. */ if (is_partition) { foreach(lc, saved_columns) { ColumnDef *restdef = lfirst(lc); bool found = false; ListCell *l; foreach(l, columns) { ColumnDef *coldef = lfirst(l); if (strcmp(coldef->colname, restdef->colname) == 0) { found = true; /* * Check for conflicts related to generated columns. * * Same rules as above: generated-ness has to match the * parent, but the contents of the generation expression * can be different. */ if (coldef->generated) { if (restdef->raw_default && !restdef->generated) ereport(ERROR, (errcode(ERRCODE_INVALID_COLUMN_DEFINITION), errmsg("column \"%s\" inherits from generated column but specifies default", restdef->colname))); if (restdef->identity) ereport(ERROR, (errcode(ERRCODE_INVALID_COLUMN_DEFINITION), errmsg("column \"%s\" inherits from generated column but specifies identity", restdef->colname))); } else { if (restdef->generated) ereport(ERROR, (errcode(ERRCODE_INVALID_COLUMN_DEFINITION), errmsg("child column \"%s\" specifies generation expression", restdef->colname), errhint("A child table column cannot be generated unless its parent column is."))); } if (coldef->generated && restdef->generated && coldef->generated != restdef->generated) ereport(ERROR, (errcode(ERRCODE_INVALID_COLUMN_DEFINITION), errmsg("column \"%s\" inherits from generated column of different kind", restdef->colname), errdetail("Parent column is %s, child column is %s.", coldef->generated == ATTRIBUTE_GENERATED_STORED ? "STORED" : "VIRTUAL", restdef->generated == ATTRIBUTE_GENERATED_STORED ? "STORED" : "VIRTUAL"))); /* * Override the parent's default value for this column * (coldef->cooked_default) with the partition's local * definition (restdef->raw_default), if there's one. It * should be physically impossible to get a cooked default * in the local definition or a raw default in the * inherited definition, but make sure they're nulls, for * future-proofing. */ Assert(restdef->cooked_default == NULL); Assert(coldef->raw_default == NULL); if (restdef->raw_default) { coldef->raw_default = restdef->raw_default; coldef->cooked_default = NULL; } } } /* complain for constraints on columns not in parent */ if (!found) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" does not exist", restdef->colname))); } } /* * If we found any conflicting parent default values, check to make sure * they were overridden by the child. */ if (have_bogus_defaults) { foreach(lc, columns) { ColumnDef *def = lfirst(lc); if (def->cooked_default == &bogus_marker) { if (def->generated) ereport(ERROR, (errcode(ERRCODE_INVALID_COLUMN_DEFINITION), errmsg("column \"%s\" inherits conflicting generation expressions", def->colname), errhint("To resolve the conflict, specify a generation expression explicitly."))); else ereport(ERROR, (errcode(ERRCODE_INVALID_COLUMN_DEFINITION), errmsg("column \"%s\" inherits conflicting default values", def->colname), errhint("To resolve the conflict, specify a default explicitly."))); } } } *supconstr = constraints; *supnotnulls = nnconstraints; return columns; } /* * MergeCheckConstraint * Try to merge an inherited CHECK constraint with previous ones * * If we inherit identically-named constraints from multiple parents, we must * merge them, or throw an error if they don't have identical definitions. * * constraints is a list of CookedConstraint structs for previous constraints. * * If the new constraint matches an existing one, then the existing * constraint's inheritance count is updated. If there is a conflict (same * name but different expression), throw an error. If the constraint neither * matches nor conflicts with an existing one, a new constraint is appended to * the list. */ static List * MergeCheckConstraint(List *constraints, const char *name, Node *expr, bool is_enforced) { ListCell *lc; CookedConstraint *newcon; foreach(lc, constraints) { CookedConstraint *ccon = (CookedConstraint *) lfirst(lc); Assert(ccon->contype == CONSTR_CHECK); /* Non-matching names never conflict */ if (strcmp(ccon->name, name) != 0) continue; if (equal(expr, ccon->expr)) { /* OK to merge constraint with existing */ if (pg_add_s16_overflow(ccon->inhcount, 1, &ccon->inhcount)) ereport(ERROR, errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED), errmsg("too many inheritance parents")); /* * When enforceability differs, the merged constraint should be * marked as ENFORCED because one of the parents is ENFORCED. */ if (!ccon->is_enforced && is_enforced) { ccon->is_enforced = true; ccon->skip_validation = false; } return constraints; } ereport(ERROR, (errcode(ERRCODE_DUPLICATE_OBJECT), errmsg("check constraint name \"%s\" appears multiple times but with different expressions", name))); } /* * Constraint couldn't be merged with an existing one and also didn't * conflict with an existing one, so add it as a new one to the list. */ newcon = palloc0_object(CookedConstraint); newcon->contype = CONSTR_CHECK; newcon->name = pstrdup(name); newcon->expr = expr; newcon->inhcount = 1; newcon->is_enforced = is_enforced; newcon->skip_validation = !is_enforced; return lappend(constraints, newcon); } /* * MergeChildAttribute * Merge given child attribute definition into given inherited attribute. * * Input arguments: * 'inh_columns' is the list of inherited ColumnDefs. * 'exist_attno' is the number of the inherited attribute in inh_columns * 'newcol_attno' is the attribute number in child table's schema definition * 'newdef' is the column/attribute definition from the child table. * * The ColumnDef in 'inh_columns' list is modified. The child attribute's * ColumnDef remains unchanged. * * Notes: * - The attribute is merged according to the rules laid out in the prologue * of MergeAttributes(). * - If matching inherited attribute exists but the child attribute can not be * merged into it, the function throws respective errors. * - A partition can not have its own column definitions. Hence this function * is applicable only to a regular inheritance child. */ static void MergeChildAttribute(List *inh_columns, int exist_attno, int newcol_attno, const ColumnDef *newdef) { char *attributeName = newdef->colname; ColumnDef *inhdef; Oid inhtypeid, newtypeid; int32 inhtypmod, newtypmod; Oid inhcollid, newcollid; if (exist_attno == newcol_attno) ereport(NOTICE, (errmsg("merging column \"%s\" with inherited definition", attributeName))); else ereport(NOTICE, (errmsg("moving and merging column \"%s\" with inherited definition", attributeName), errdetail("User-specified column moved to the position of the inherited column."))); inhdef = list_nth_node(ColumnDef, inh_columns, exist_attno - 1); /* * Must have the same type and typmod */ typenameTypeIdAndMod(NULL, inhdef->typeName, &inhtypeid, &inhtypmod); typenameTypeIdAndMod(NULL, newdef->typeName, &newtypeid, &newtypmod); if (inhtypeid != newtypeid || inhtypmod != newtypmod) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("column \"%s\" has a type conflict", attributeName), errdetail("%s versus %s", format_type_with_typemod(inhtypeid, inhtypmod), format_type_with_typemod(newtypeid, newtypmod)))); /* * Must have the same collation */ inhcollid = GetColumnDefCollation(NULL, inhdef, inhtypeid); newcollid = GetColumnDefCollation(NULL, newdef, newtypeid); if (inhcollid != newcollid) ereport(ERROR, (errcode(ERRCODE_COLLATION_MISMATCH), errmsg("column \"%s\" has a collation conflict", attributeName), errdetail("\"%s\" versus \"%s\"", get_collation_name(inhcollid), get_collation_name(newcollid)))); /* * Identity is never inherited by a regular inheritance child. Pick * child's identity definition if there's one. */ inhdef->identity = newdef->identity; /* * Copy storage parameter */ if (inhdef->storage == 0) inhdef->storage = newdef->storage; else if (newdef->storage != 0 && inhdef->storage != newdef->storage) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("column \"%s\" has a storage parameter conflict", attributeName), errdetail("%s versus %s", storage_name(inhdef->storage), storage_name(newdef->storage)))); /* * Copy compression parameter */ if (inhdef->compression == NULL) inhdef->compression = newdef->compression; else if (newdef->compression != NULL) { if (strcmp(inhdef->compression, newdef->compression) != 0) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("column \"%s\" has a compression method conflict", attributeName), errdetail("%s versus %s", inhdef->compression, newdef->compression))); } /* * Merge of not-null constraints = OR 'em together */ inhdef->is_not_null |= newdef->is_not_null; /* * Check for conflicts related to generated columns. * * If the parent column is generated, the child column will be made a * generated column if it isn't already. If it is a generated column, * we'll take its generation expression in preference to the parent's. We * must check that the child column doesn't specify a default value or * identity, which matches the rules for a single column in * parse_utilcmd.c. * * Conversely, if the parent column is not generated, the child column * can't be either. (We used to allow that, but it results in being able * to override the generation expression via UPDATEs through the parent.) */ if (inhdef->generated) { if (newdef->raw_default && !newdef->generated) ereport(ERROR, (errcode(ERRCODE_INVALID_COLUMN_DEFINITION), errmsg("column \"%s\" inherits from generated column but specifies default", inhdef->colname))); if (newdef->identity) ereport(ERROR, (errcode(ERRCODE_INVALID_COLUMN_DEFINITION), errmsg("column \"%s\" inherits from generated column but specifies identity", inhdef->colname))); } else { if (newdef->generated) ereport(ERROR, (errcode(ERRCODE_INVALID_COLUMN_DEFINITION), errmsg("child column \"%s\" specifies generation expression", inhdef->colname), errhint("A child table column cannot be generated unless its parent column is."))); } if (inhdef->generated && newdef->generated && newdef->generated != inhdef->generated) ereport(ERROR, (errcode(ERRCODE_INVALID_COLUMN_DEFINITION), errmsg("column \"%s\" inherits from generated column of different kind", inhdef->colname), errdetail("Parent column is %s, child column is %s.", inhdef->generated == ATTRIBUTE_GENERATED_STORED ? "STORED" : "VIRTUAL", newdef->generated == ATTRIBUTE_GENERATED_STORED ? "STORED" : "VIRTUAL"))); /* * If new def has a default, override previous default */ if (newdef->raw_default != NULL) { inhdef->raw_default = newdef->raw_default; inhdef->cooked_default = newdef->cooked_default; } /* Mark the column as locally defined */ inhdef->is_local = true; } /* * MergeInheritedAttribute * Merge given parent attribute definition into specified attribute * inherited from the previous parents. * * Input arguments: * 'inh_columns' is the list of previously inherited ColumnDefs. * 'exist_attno' is the number the existing matching attribute in inh_columns. * 'newdef' is the new parent column/attribute definition to be merged. * * The matching ColumnDef in 'inh_columns' list is modified and returned. * * Notes: * - The attribute is merged according to the rules laid out in the prologue * of MergeAttributes(). * - If matching inherited attribute exists but the new attribute can not be * merged into it, the function throws respective errors. * - A partition inherits from only a single parent. Hence this function is * applicable only to a regular inheritance. */ static ColumnDef * MergeInheritedAttribute(List *inh_columns, int exist_attno, const ColumnDef *newdef) { char *attributeName = newdef->colname; ColumnDef *prevdef; Oid prevtypeid, newtypeid; int32 prevtypmod, newtypmod; Oid prevcollid, newcollid; ereport(NOTICE, (errmsg("merging multiple inherited definitions of column \"%s\"", attributeName))); prevdef = list_nth_node(ColumnDef, inh_columns, exist_attno - 1); /* * Must have the same type and typmod */ typenameTypeIdAndMod(NULL, prevdef->typeName, &prevtypeid, &prevtypmod); typenameTypeIdAndMod(NULL, newdef->typeName, &newtypeid, &newtypmod); if (prevtypeid != newtypeid || prevtypmod != newtypmod) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("inherited column \"%s\" has a type conflict", attributeName), errdetail("%s versus %s", format_type_with_typemod(prevtypeid, prevtypmod), format_type_with_typemod(newtypeid, newtypmod)))); /* * Must have the same collation */ prevcollid = GetColumnDefCollation(NULL, prevdef, prevtypeid); newcollid = GetColumnDefCollation(NULL, newdef, newtypeid); if (prevcollid != newcollid) ereport(ERROR, (errcode(ERRCODE_COLLATION_MISMATCH), errmsg("inherited column \"%s\" has a collation conflict", attributeName), errdetail("\"%s\" versus \"%s\"", get_collation_name(prevcollid), get_collation_name(newcollid)))); /* * Copy/check storage parameter */ if (prevdef->storage == 0) prevdef->storage = newdef->storage; else if (prevdef->storage != newdef->storage) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("inherited column \"%s\" has a storage parameter conflict", attributeName), errdetail("%s versus %s", storage_name(prevdef->storage), storage_name(newdef->storage)))); /* * Copy/check compression parameter */ if (prevdef->compression == NULL) prevdef->compression = newdef->compression; else if (newdef->compression != NULL) { if (strcmp(prevdef->compression, newdef->compression) != 0) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("column \"%s\" has a compression method conflict", attributeName), errdetail("%s versus %s", prevdef->compression, newdef->compression))); } /* * Check for GENERATED conflicts */ if (prevdef->generated != newdef->generated) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("inherited column \"%s\" has a generation conflict", attributeName))); /* * Default and other constraints are handled by the caller. */ if (pg_add_s16_overflow(prevdef->inhcount, 1, &prevdef->inhcount)) ereport(ERROR, errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED), errmsg("too many inheritance parents")); return prevdef; } /* * StoreCatalogInheritance * Updates the system catalogs with proper inheritance information. * * supers is a list of the OIDs of the new relation's direct ancestors. */ static void StoreCatalogInheritance(Oid relationId, List *supers, bool child_is_partition) { Relation relation; int32 seqNumber; ListCell *entry; /* * sanity checks */ Assert(OidIsValid(relationId)); if (supers == NIL) return; /* * Store INHERITS information in pg_inherits using direct ancestors only. * Also enter dependencies on the direct ancestors, and make sure they are * marked with relhassubclass = true. * * (Once upon a time, both direct and indirect ancestors were found here * and then entered into pg_ipl. Since that catalog doesn't exist * anymore, there's no need to look for indirect ancestors.) */ relation = table_open(InheritsRelationId, RowExclusiveLock); seqNumber = 1; foreach(entry, supers) { Oid parentOid = lfirst_oid(entry); StoreCatalogInheritance1(relationId, parentOid, seqNumber, relation, child_is_partition); seqNumber++; } table_close(relation, RowExclusiveLock); } /* * Make catalog entries showing relationId as being an inheritance child * of parentOid. inhRelation is the already-opened pg_inherits catalog. */ static void StoreCatalogInheritance1(Oid relationId, Oid parentOid, int32 seqNumber, Relation inhRelation, bool child_is_partition) { ObjectAddress childobject, parentobject; /* store the pg_inherits row */ StoreSingleInheritance(relationId, parentOid, seqNumber); /* * Store a dependency too */ parentobject.classId = RelationRelationId; parentobject.objectId = parentOid; parentobject.objectSubId = 0; childobject.classId = RelationRelationId; childobject.objectId = relationId; childobject.objectSubId = 0; recordDependencyOn(&childobject, &parentobject, child_dependency_type(child_is_partition)); /* * Post creation hook of this inheritance. Since object_access_hook * doesn't take multiple object identifiers, we relay oid of parent * relation using auxiliary_id argument. */ InvokeObjectPostAlterHookArg(InheritsRelationId, relationId, 0, parentOid, false); /* * Mark the parent as having subclasses. */ SetRelationHasSubclass(parentOid, true); } /* * Look for an existing column entry with the given name. * * Returns the index (starting with 1) if attribute already exists in columns, * 0 if it doesn't. */ static int findAttrByName(const char *attributeName, const List *columns) { ListCell *lc; int i = 1; foreach(lc, columns) { if (strcmp(attributeName, lfirst_node(ColumnDef, lc)->colname) == 0) return i; i++; } return 0; } /* * SetRelationHasSubclass * Set the value of the relation's relhassubclass field in pg_class. * * It's always safe to set this field to true, because all SQL commands are * ready to see true and then find no children. On the other hand, commands * generally assume zero children if this is false. * * Caller must hold any self-exclusive lock until end of transaction. If the * new value is false, caller must have acquired that lock before reading the * evidence that justified the false value. That way, it properly waits if * another backend is simultaneously concluding no need to change the tuple * (new and old values are true). * * NOTE: an important side-effect of this operation is that an SI invalidation * message is sent out to all backends --- including me --- causing plans * referencing the relation to be rebuilt with the new list of children. * This must happen even if we find that no change is needed in the pg_class * row. */ void SetRelationHasSubclass(Oid relationId, bool relhassubclass) { Relation relationRelation; HeapTuple tuple; Form_pg_class classtuple; Assert(CheckRelationOidLockedByMe(relationId, ShareUpdateExclusiveLock, false) || CheckRelationOidLockedByMe(relationId, ShareRowExclusiveLock, true)); /* * Fetch a modifiable copy of the tuple, modify it, update pg_class. */ relationRelation = table_open(RelationRelationId, RowExclusiveLock); tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relationId)); if (!HeapTupleIsValid(tuple)) elog(ERROR, "cache lookup failed for relation %u", relationId); classtuple = (Form_pg_class) GETSTRUCT(tuple); if (classtuple->relhassubclass != relhassubclass) { classtuple->relhassubclass = relhassubclass; CatalogTupleUpdate(relationRelation, &tuple->t_self, tuple); } else { /* no need to change tuple, but force relcache rebuild anyway */ CacheInvalidateRelcacheByTuple(tuple); } heap_freetuple(tuple); table_close(relationRelation, RowExclusiveLock); } /* * CheckRelationTableSpaceMove * Check if relation can be moved to new tablespace. * * NOTE: The caller must hold AccessExclusiveLock on the relation. * * Returns true if the relation can be moved to the new tablespace; raises * an error if it is not possible to do the move; returns false if the move * would have no effect. */ bool CheckRelationTableSpaceMove(Relation rel, Oid newTableSpaceId) { Oid oldTableSpaceId; /* * No work if no change in tablespace. Note that MyDatabaseTableSpace is * stored as 0. */ oldTableSpaceId = rel->rd_rel->reltablespace; if (newTableSpaceId == oldTableSpaceId || (newTableSpaceId == MyDatabaseTableSpace && oldTableSpaceId == 0)) return false; /* * We cannot support moving mapped relations into different tablespaces. * (In particular this eliminates all shared catalogs.) */ if (RelationIsMapped(rel)) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot move system relation \"%s\"", RelationGetRelationName(rel)))); /* Cannot move a non-shared relation into pg_global */ if (newTableSpaceId == GLOBALTABLESPACE_OID) ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("only shared relations can be placed in pg_global tablespace"))); /* * Do not allow moving temp tables of other backends ... their local * buffer manager is not going to cope. */ if (RELATION_IS_OTHER_TEMP(rel)) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot move temporary tables of other sessions"))); return true; } /* * SetRelationTableSpace * Set new reltablespace and relfilenumber in pg_class entry. * * newTableSpaceId is the new tablespace for the relation, and * newRelFilenumber its new filenumber. If newRelFilenumber is * InvalidRelFileNumber, this field is not updated. * * NOTE: The caller must hold AccessExclusiveLock on the relation. * * The caller of this routine had better check if a relation can be * moved to this new tablespace by calling CheckRelationTableSpaceMove() * first, and is responsible for making the change visible with * CommandCounterIncrement(). */ void SetRelationTableSpace(Relation rel, Oid newTableSpaceId, RelFileNumber newRelFilenumber) { Relation pg_class; HeapTuple tuple; ItemPointerData otid; Form_pg_class rd_rel; Oid reloid = RelationGetRelid(rel); Assert(CheckRelationTableSpaceMove(rel, newTableSpaceId)); /* Get a modifiable copy of the relation's pg_class row. */ pg_class = table_open(RelationRelationId, RowExclusiveLock); tuple = SearchSysCacheLockedCopy1(RELOID, ObjectIdGetDatum(reloid)); if (!HeapTupleIsValid(tuple)) elog(ERROR, "cache lookup failed for relation %u", reloid); otid = tuple->t_self; rd_rel = (Form_pg_class) GETSTRUCT(tuple); /* Update the pg_class row. */ rd_rel->reltablespace = (newTableSpaceId == MyDatabaseTableSpace) ? InvalidOid : newTableSpaceId; if (RelFileNumberIsValid(newRelFilenumber)) rd_rel->relfilenode = newRelFilenumber; CatalogTupleUpdate(pg_class, &otid, tuple); UnlockTuple(pg_class, &otid, InplaceUpdateTupleLock); /* * Record dependency on tablespace. This is only required for relations * that have no physical storage. */ if (!RELKIND_HAS_STORAGE(rel->rd_rel->relkind)) changeDependencyOnTablespace(RelationRelationId, reloid, rd_rel->reltablespace); heap_freetuple(tuple); table_close(pg_class, RowExclusiveLock); } /* * renameatt_check - basic sanity checks before attribute rename */ static void renameatt_check(Oid myrelid, Form_pg_class classform, bool recursing) { char relkind = classform->relkind; if (classform->reloftype && !recursing) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot rename column of typed table"))); /* * Renaming the columns of sequences or toast tables doesn't actually * break anything from the system's point of view, since internal * references are by attnum. But it doesn't seem right to allow users to * change names that are hardcoded into the system, hence the following * restriction. */ if (relkind != RELKIND_RELATION && relkind != RELKIND_VIEW && relkind != RELKIND_MATVIEW && relkind != RELKIND_COMPOSITE_TYPE && relkind != RELKIND_INDEX && relkind != RELKIND_PARTITIONED_INDEX && relkind != RELKIND_FOREIGN_TABLE && relkind != RELKIND_PARTITIONED_TABLE) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot rename columns of relation \"%s\"", NameStr(classform->relname)), errdetail_relkind_not_supported(relkind))); /* * permissions checking. only the owner of a class can change its schema. */ if (!object_ownercheck(RelationRelationId, myrelid, GetUserId())) aclcheck_error(ACLCHECK_NOT_OWNER, get_relkind_objtype(get_rel_relkind(myrelid)), NameStr(classform->relname)); /* * Conflict log tables are used internally for logical replication * conflict logging and should not be modified directly, as it could * disrupt conflict logging. */ if (IsConflictLogTableClass(classform)) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot rename columns of conflict log table \"%s\"", NameStr(classform->relname)), errdetail("Conflict log tables are system-managed tables for logical replication conflicts."))); if (!allowSystemTableMods && IsSystemClass(myrelid, classform)) ereport(ERROR, (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), errmsg("permission denied: \"%s\" is a system catalog", NameStr(classform->relname)))); } /* * renameatt_internal - workhorse for renameatt * * Return value is the attribute number in the 'myrelid' relation. */ static AttrNumber renameatt_internal(Oid myrelid, const char *oldattname, const char *newattname, bool recurse, bool recursing, int expected_parents, DropBehavior behavior) { Relation targetrelation; Relation attrelation; HeapTuple atttup; Form_pg_attribute attform; AttrNumber attnum; /* * Grab an exclusive lock on the target table, which we will NOT release * until end of transaction. */ targetrelation = relation_open(myrelid, AccessExclusiveLock); renameatt_check(myrelid, RelationGetForm(targetrelation), recursing); /* * if the 'recurse' flag is set then we are supposed to rename this * attribute in all classes that inherit from 'relname' (as well as in * 'relname'). * * any permissions or problems with duplicate attributes will cause the * whole transaction to abort, which is what we want -- all or nothing. */ if (recurse) { List *child_oids, *child_numparents; ListCell *lo, *li; /* * we need the number of parents for each child so that the recursive * calls to renameatt() can determine whether there are any parents * outside the inheritance hierarchy being processed. */ child_oids = find_all_inheritors(myrelid, AccessExclusiveLock, &child_numparents); /* * find_all_inheritors does the recursive search of the inheritance * hierarchy, so all we have to do is process all of the relids in the * list that it returns. */ forboth(lo, child_oids, li, child_numparents) { Oid childrelid = lfirst_oid(lo); int numparents = lfirst_int(li); if (childrelid == myrelid) continue; /* note we need not recurse again */ renameatt_internal(childrelid, oldattname, newattname, false, true, numparents, behavior); } } else { /* * If we are told not to recurse, there had better not be any child * tables; else the rename would put them out of step. * * expected_parents will only be 0 if we are not already recursing. */ if (expected_parents == 0 && find_inheritance_children(myrelid, NoLock) != NIL) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("inherited column \"%s\" must be renamed in child tables too", oldattname))); } /* rename attributes in typed tables of composite type */ if (targetrelation->rd_rel->relkind == RELKIND_COMPOSITE_TYPE) { List *child_oids; ListCell *lo; child_oids = find_typed_table_dependencies(targetrelation->rd_rel->reltype, RelationGetRelationName(targetrelation), behavior); foreach(lo, child_oids) renameatt_internal(lfirst_oid(lo), oldattname, newattname, true, true, 0, behavior); } attrelation = table_open(AttributeRelationId, RowExclusiveLock); atttup = SearchSysCacheCopyAttName(myrelid, oldattname); if (!HeapTupleIsValid(atttup)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" does not exist", oldattname))); attform = (Form_pg_attribute) GETSTRUCT(atttup); attnum = attform->attnum; if (attnum <= 0) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot rename system column \"%s\"", oldattname))); /* * if the attribute is inherited, forbid the renaming. if this is a * top-level call to renameatt(), then expected_parents will be 0, so the * effect of this code will be to prohibit the renaming if the attribute * is inherited at all. if this is a recursive call to renameatt(), * expected_parents will be the number of parents the current relation has * within the inheritance hierarchy being processed, so we'll prohibit the * renaming only if there are additional parents from elsewhere. */ if (attform->attinhcount > expected_parents) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("cannot rename inherited column \"%s\"", oldattname))); /* new name should not already exist */ (void) check_for_column_name_collision(targetrelation, newattname, false); /* apply the update */ namestrcpy(&(attform->attname), newattname); CatalogTupleUpdate(attrelation, &atttup->t_self, atttup); InvokeObjectPostAlterHook(RelationRelationId, myrelid, attnum); heap_freetuple(atttup); table_close(attrelation, RowExclusiveLock); relation_close(targetrelation, NoLock); /* close rel but keep lock */ return attnum; } /* * Perform permissions and integrity checks before acquiring a relation lock. */ static void RangeVarCallbackForRenameAttribute(const RangeVar *rv, Oid relid, Oid oldrelid, void *arg) { HeapTuple tuple; Form_pg_class form; tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relid)); if (!HeapTupleIsValid(tuple)) return; /* concurrently dropped */ form = (Form_pg_class) GETSTRUCT(tuple); renameatt_check(relid, form, false); ReleaseSysCache(tuple); } /* * renameatt - changes the name of an attribute in a relation * * The returned ObjectAddress is that of the renamed column. */ ObjectAddress renameatt(RenameStmt *stmt) { Oid relid; AttrNumber attnum; ObjectAddress address; /* lock level taken here should match renameatt_internal */ relid = RangeVarGetRelidExtended(stmt->relation, AccessExclusiveLock, stmt->missing_ok ? RVR_MISSING_OK : 0, RangeVarCallbackForRenameAttribute, NULL); if (!OidIsValid(relid)) { ereport(NOTICE, (errmsg("relation \"%s\" does not exist, skipping", stmt->relation->relname))); return InvalidObjectAddress; } attnum = renameatt_internal(relid, stmt->subname, /* old att name */ stmt->newname, /* new att name */ stmt->relation->inh, /* recursive? */ false, /* recursing? */ 0, /* expected inhcount */ stmt->behavior); ObjectAddressSubSet(address, RelationRelationId, relid, attnum); return address; } /* * same logic as renameatt_internal */ static ObjectAddress rename_constraint_internal(Oid myrelid, Oid mytypid, const char *oldconname, const char *newconname, bool recurse, bool recursing, int expected_parents) { Relation targetrelation = NULL; Oid constraintOid; HeapTuple tuple; Form_pg_constraint con; ObjectAddress address; Assert(!myrelid || !mytypid); if (mytypid) { constraintOid = get_domain_constraint_oid(mytypid, oldconname, false); } else { targetrelation = relation_open(myrelid, AccessExclusiveLock); /* * don't tell it whether we're recursing; we allow changing typed * tables here */ renameatt_check(myrelid, RelationGetForm(targetrelation), false); constraintOid = get_relation_constraint_oid(myrelid, oldconname, false); } tuple = SearchSysCache1(CONSTROID, ObjectIdGetDatum(constraintOid)); if (!HeapTupleIsValid(tuple)) elog(ERROR, "cache lookup failed for constraint %u", constraintOid); con = (Form_pg_constraint) GETSTRUCT(tuple); if (myrelid && (con->contype == CONSTRAINT_CHECK || con->contype == CONSTRAINT_NOTNULL) && !con->connoinherit) { if (recurse) { List *child_oids, *child_numparents; ListCell *lo, *li; child_oids = find_all_inheritors(myrelid, AccessExclusiveLock, &child_numparents); forboth(lo, child_oids, li, child_numparents) { Oid childrelid = lfirst_oid(lo); int numparents = lfirst_int(li); if (childrelid == myrelid) continue; rename_constraint_internal(childrelid, InvalidOid, oldconname, newconname, false, true, numparents); } } else { if (expected_parents == 0 && find_inheritance_children(myrelid, NoLock) != NIL) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("inherited constraint \"%s\" must be renamed in child tables too", oldconname))); } if (con->coninhcount > expected_parents) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("cannot rename inherited constraint \"%s\"", oldconname))); } if (con->conindid && (con->contype == CONSTRAINT_PRIMARY || con->contype == CONSTRAINT_UNIQUE || con->contype == CONSTRAINT_EXCLUSION)) /* rename the index; this renames the constraint as well */ RenameRelationInternal(con->conindid, newconname, false, true); else RenameConstraintById(constraintOid, newconname); ObjectAddressSet(address, ConstraintRelationId, constraintOid); ReleaseSysCache(tuple); if (targetrelation) { /* * Invalidate relcache so as others can see the new constraint name. */ CacheInvalidateRelcache(targetrelation); relation_close(targetrelation, NoLock); /* close rel but keep lock */ } return address; } ObjectAddress RenameConstraint(RenameStmt *stmt) { Oid relid = InvalidOid; Oid typid = InvalidOid; if (stmt->renameType == OBJECT_DOMCONSTRAINT) { Relation rel; HeapTuple tup; typid = typenameTypeId(NULL, makeTypeNameFromNameList(castNode(List, stmt->object))); rel = table_open(TypeRelationId, RowExclusiveLock); tup = SearchSysCache1(TYPEOID, ObjectIdGetDatum(typid)); if (!HeapTupleIsValid(tup)) elog(ERROR, "cache lookup failed for type %u", typid); checkDomainOwner(tup); ReleaseSysCache(tup); table_close(rel, NoLock); } else { /* lock level taken here should match rename_constraint_internal */ relid = RangeVarGetRelidExtended(stmt->relation, AccessExclusiveLock, stmt->missing_ok ? RVR_MISSING_OK : 0, RangeVarCallbackForRenameAttribute, NULL); if (!OidIsValid(relid)) { ereport(NOTICE, (errmsg("relation \"%s\" does not exist, skipping", stmt->relation->relname))); return InvalidObjectAddress; } } return rename_constraint_internal(relid, typid, stmt->subname, stmt->newname, (stmt->relation && stmt->relation->inh), /* recursive? */ false, /* recursing? */ 0 /* expected inhcount */ ); } /* * Execute ALTER TABLE/INDEX/SEQUENCE/VIEW/MATERIALIZED VIEW/FOREIGN TABLE/PROPERTY GRAPH * RENAME */ ObjectAddress RenameRelation(RenameStmt *stmt) { bool is_index_stmt = stmt->renameType == OBJECT_INDEX; Oid relid; ObjectAddress address; /* * Grab an exclusive lock on the target table, index, sequence, view, * materialized view, or foreign table, which we will NOT release until * end of transaction. * * Lock level used here should match RenameRelationInternal, to avoid lock * escalation. However, because ALTER INDEX can be used with any relation * type, we mustn't believe without verification. */ for (;;) { LOCKMODE lockmode; char relkind; bool obj_is_index; lockmode = is_index_stmt ? ShareUpdateExclusiveLock : AccessExclusiveLock; relid = RangeVarGetRelidExtended(stmt->relation, lockmode, stmt->missing_ok ? RVR_MISSING_OK : 0, RangeVarCallbackForAlterRelation, stmt); if (!OidIsValid(relid)) { ereport(NOTICE, (errmsg("relation \"%s\" does not exist, skipping", stmt->relation->relname))); return InvalidObjectAddress; } /* * We allow mismatched statement and object types (e.g., ALTER INDEX * to rename a table), but we might've used the wrong lock level. If * that happens, retry with the correct lock level. We don't bother * if we already acquired AccessExclusiveLock with an index, however. */ relkind = get_rel_relkind(relid); obj_is_index = (relkind == RELKIND_INDEX || relkind == RELKIND_PARTITIONED_INDEX); if (obj_is_index || is_index_stmt == obj_is_index) break; UnlockRelationOid(relid, lockmode); is_index_stmt = obj_is_index; } /* Do the work */ RenameRelationInternal(relid, stmt->newname, false, is_index_stmt); ObjectAddressSet(address, RelationRelationId, relid); return address; } /* * RenameRelationInternal - change the name of a relation */ void RenameRelationInternal(Oid myrelid, const char *newrelname, bool is_internal, bool is_index) { Relation targetrelation; Relation relrelation; /* for RELATION relation */ ItemPointerData otid; HeapTuple reltup; Form_pg_class relform; Oid namespaceId; /* * Grab a lock on the target relation, which we will NOT release until end * of transaction. We need at least a self-exclusive lock so that * concurrent DDL doesn't overwrite the rename if they start updating * while still seeing the old version. The lock also guards against * triggering relcache reloads in concurrent sessions, which might not * handle this information changing under them. For indexes, we can use a * reduced lock level because RelationReloadIndexInfo() handles indexes * specially. */ targetrelation = relation_open(myrelid, is_index ? ShareUpdateExclusiveLock : AccessExclusiveLock); namespaceId = RelationGetNamespace(targetrelation); /* * Find relation's pg_class tuple, and make sure newrelname isn't in use. */ relrelation = table_open(RelationRelationId, RowExclusiveLock); reltup = SearchSysCacheLockedCopy1(RELOID, ObjectIdGetDatum(myrelid)); if (!HeapTupleIsValid(reltup)) /* shouldn't happen */ elog(ERROR, "cache lookup failed for relation %u", myrelid); otid = reltup->t_self; relform = (Form_pg_class) GETSTRUCT(reltup); if (get_relname_relid(newrelname, namespaceId) != InvalidOid) ereport(ERROR, (errcode(ERRCODE_DUPLICATE_TABLE), errmsg("relation \"%s\" already exists", newrelname))); /* * RenameRelation is careful not to believe the caller's idea of the * relation kind being handled. We don't have to worry about this, but * let's not be totally oblivious to it. We can process an index as * not-an-index, but not the other way around. */ Assert(!is_index || is_index == (targetrelation->rd_rel->relkind == RELKIND_INDEX || targetrelation->rd_rel->relkind == RELKIND_PARTITIONED_INDEX)); /* * Update pg_class tuple with new relname. (Scribbling on reltup is OK * because it's a copy...) */ namestrcpy(&(relform->relname), newrelname); CatalogTupleUpdate(relrelation, &otid, reltup); UnlockTuple(relrelation, &otid, InplaceUpdateTupleLock); InvokeObjectPostAlterHookArg(RelationRelationId, myrelid, 0, InvalidOid, is_internal); heap_freetuple(reltup); table_close(relrelation, RowExclusiveLock); /* * Also rename the associated type, if any. */ if (OidIsValid(targetrelation->rd_rel->reltype)) RenameTypeInternal(targetrelation->rd_rel->reltype, newrelname, namespaceId); /* * Also rename the associated constraint, if any. */ if (targetrelation->rd_rel->relkind == RELKIND_INDEX || targetrelation->rd_rel->relkind == RELKIND_PARTITIONED_INDEX) { Oid constraintId = get_index_constraint(myrelid); if (OidIsValid(constraintId)) RenameConstraintById(constraintId, newrelname); } /* * Close rel, but keep lock! */ relation_close(targetrelation, NoLock); } /* * ResetRelRewrite - reset relrewrite */ void ResetRelRewrite(Oid myrelid) { Relation relrelation; /* for RELATION relation */ HeapTuple reltup; Form_pg_class relform; /* * Find relation's pg_class tuple. */ relrelation = table_open(RelationRelationId, RowExclusiveLock); reltup = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(myrelid)); if (!HeapTupleIsValid(reltup)) /* shouldn't happen */ elog(ERROR, "cache lookup failed for relation %u", myrelid); relform = (Form_pg_class) GETSTRUCT(reltup); /* * Update pg_class tuple. */ relform->relrewrite = InvalidOid; CatalogTupleUpdate(relrelation, &reltup->t_self, reltup); heap_freetuple(reltup); table_close(relrelation, RowExclusiveLock); } /* * Disallow ALTER TABLE (and similar commands) when the current backend has * any open reference to the target table besides the one just acquired by * the calling command; this implies there's an open cursor or active plan. * We need this check because our lock doesn't protect us against stomping * on our own foot, only other people's feet! * * For ALTER TABLE, the only case known to cause serious trouble is ALTER * COLUMN TYPE, and some changes are obviously pretty benign, so this could * possibly be relaxed to only error out for certain types of alterations. * But the use-case for allowing any of these things is not obvious, so we * won't work hard at it for now. * * We also reject these commands if there are any pending AFTER trigger events * for the rel. This is certainly necessary for the rewriting variants of * ALTER TABLE, because they don't preserve tuple TIDs and so the pending * events would try to fetch the wrong tuples. It might be overly cautious * in other cases, but again it seems better to err on the side of paranoia. * * REINDEX calls this with "rel" referencing the index to be rebuilt; here * we are worried about active indexscans on the index. The trigger-event * check can be skipped, since we are doing no damage to the parent table. * * The statement name (eg, "ALTER TABLE") is passed for use in error messages. */ void CheckTableNotInUse(Relation rel, const char *stmt) { int expected_refcnt; expected_refcnt = rel->rd_isnailed ? 2 : 1; if (rel->rd_refcnt != expected_refcnt) ereport(ERROR, (errcode(ERRCODE_OBJECT_IN_USE), /* translator: first %s is a SQL command, eg ALTER TABLE */ errmsg("cannot %s \"%s\" because it is being used by active queries in this session", stmt, RelationGetRelationName(rel)))); if (rel->rd_rel->relkind != RELKIND_INDEX && rel->rd_rel->relkind != RELKIND_PARTITIONED_INDEX && AfterTriggerPendingOnRel(RelationGetRelid(rel))) ereport(ERROR, (errcode(ERRCODE_OBJECT_IN_USE), /* translator: first %s is a SQL command, eg ALTER TABLE */ errmsg("cannot %s \"%s\" because it has pending trigger events", stmt, RelationGetRelationName(rel)))); } /* * CheckAlterTableIsSafe * Verify that it's safe to allow ALTER TABLE on this relation. * * This consists of CheckTableNotInUse() plus a check that the relation * isn't another session's temp table. We must split out the temp-table * check because there are callers of CheckTableNotInUse() that don't want * that, notably DROP TABLE. (We must allow DROP or we couldn't clean out * an orphaned temp schema.) Compare truncate_check_activity(). */ static void CheckAlterTableIsSafe(Relation rel) { /* * Don't allow ALTER on temp tables of other backends. Their local buffer * manager is not going to cope if we need to change the table's contents. * Even if we don't, there may be optimizations that assume temp tables * aren't subject to such interference. */ if (RELATION_IS_OTHER_TEMP(rel)) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter temporary tables of other sessions"))); /* * Also check for active uses of the relation in the current transaction, * including open scans and pending AFTER trigger events. */ CheckTableNotInUse(rel, "ALTER TABLE"); } /* * AlterTableLookupRelation * Look up, and lock, the OID for the relation named by an alter table * statement. */ Oid AlterTableLookupRelation(AlterTableStmt *stmt, LOCKMODE lockmode) { return RangeVarGetRelidExtended(stmt->relation, lockmode, stmt->missing_ok ? RVR_MISSING_OK : 0, RangeVarCallbackForAlterRelation, stmt); } /* * AlterTable * Execute ALTER TABLE, which can be a list of subcommands * * ALTER TABLE is performed in three phases: * 1. Examine subcommands and perform pre-transformation checking. * 2. Validate and transform subcommands, and update system catalogs. * 3. Scan table(s) to check new constraints, and optionally recopy * the data into new table(s). * Phase 3 is not performed unless one or more of the subcommands requires * it. The intention of this design is to allow multiple independent * updates of the table schema to be performed with only one pass over the * data. * * ATPrepCmd performs phase 1. A "work queue" entry is created for * each table to be affected (there may be multiple affected tables if the * commands traverse a table inheritance hierarchy). Also we do preliminary * validation of the subcommands. Because earlier subcommands may change * the catalog state seen by later commands, there are limits to what can * be done in this phase. Generally, this phase acquires table locks, * checks permissions and relkind, and recurses to find child tables. * * ATRewriteCatalogs performs phase 2 for each affected table. * Certain subcommands need to be performed before others to avoid * unnecessary conflicts; for example, DROP COLUMN should come before * ADD COLUMN. Therefore phase 1 divides the subcommands into multiple * lists, one for each logical "pass" of phase 2. * * ATRewriteTables performs phase 3 for those tables that need it. * * For most subcommand types, phases 2 and 3 do no explicit recursion, * since phase 1 already does it. However, for certain subcommand types * it is only possible to determine how to recurse at phase 2 time; for * those cases, phase 1 sets the cmd->recurse flag. * * Thanks to the magic of MVCC, an error anywhere along the way rolls back * the whole operation; we don't have to do anything special to clean up. * * The caller must lock the relation, with an appropriate lock level * for the subcommands requested, using AlterTableGetLockLevel(stmt->cmds) * or higher. We pass the lock level down * so that we can apply it recursively to inherited tables. Note that the * lock level we want as we recurse might well be higher than required for * that specific subcommand. So we pass down the overall lock requirement, * rather than reassess it at lower levels. * * The caller also provides a "context" which is to be passed back to * utility.c when we need to execute a subcommand such as CREATE INDEX. * Some of the fields therein, such as the relid, are used here as well. */ void AlterTable(AlterTableStmt *stmt, LOCKMODE lockmode, AlterTableUtilityContext *context) { Relation rel; /* Caller is required to provide an adequate lock. */ rel = relation_open(context->relid, NoLock); CheckAlterTableIsSafe(rel); ATController(stmt, rel, stmt->cmds, stmt->relation->inh, lockmode, context); } /* * AlterTableInternal * * ALTER TABLE with target specified by OID * * We do not reject if the relation is already open, because it's quite * likely that one or more layers of caller have it open. That means it * is unsafe to use this entry point for alterations that could break * existing query plans. On the assumption it's not used for such, we * don't have to reject pending AFTER triggers, either. * * Also, since we don't have an AlterTableUtilityContext, this cannot be * used for any subcommand types that require parse transformation or * could generate subcommands that have to be passed to ProcessUtility. */ void AlterTableInternal(Oid relid, List *cmds, bool recurse) { Relation rel; LOCKMODE lockmode = AlterTableGetLockLevel(cmds); rel = relation_open(relid, lockmode); EventTriggerAlterTableRelid(relid); ATController(NULL, rel, cmds, recurse, lockmode, NULL); } /* * AlterTableGetLockLevel * * Sets the overall lock level required for the supplied list of subcommands. * Policy for doing this set according to needs of AlterTable(), see * comments there for overall explanation. * * Function is called before and after parsing, so it must give same * answer each time it is called. Some subcommands are transformed * into other subcommand types, so the transform must never be made to a * lower lock level than previously assigned. All transforms are noted below. * * Since this is called before we lock the table we cannot use table metadata * to influence the type of lock we acquire. * * There should be no lockmodes hardcoded into the subcommand functions. All * lockmode decisions for ALTER TABLE are made here only. The one exception is * ALTER TABLE RENAME which is treated as a different statement type T_RenameStmt * and does not travel through this section of code and cannot be combined with * any of the subcommands given here. * * Note that Hot Standby only knows about AccessExclusiveLocks on the primary * so any changes that might affect SELECTs running on standbys need to use * AccessExclusiveLocks even if you think a lesser lock would do, unless you * have a solution for that also. * * Also note that pg_dump uses only an AccessShareLock, meaning that anything * that takes a lock less than AccessExclusiveLock can change object definitions * while pg_dump is running. Be careful to check that the appropriate data is * derived by pg_dump using an MVCC snapshot, rather than syscache lookups, * otherwise we might end up with an inconsistent dump that can't restore. */ LOCKMODE AlterTableGetLockLevel(List *cmds) { /* * This only works if we read catalog tables using MVCC snapshots. */ ListCell *lcmd; LOCKMODE lockmode = ShareUpdateExclusiveLock; foreach(lcmd, cmds) { AlterTableCmd *cmd = (AlterTableCmd *) lfirst(lcmd); LOCKMODE cmd_lockmode = AccessExclusiveLock; /* default for compiler */ switch (cmd->subtype) { /* * These subcommands rewrite the heap, so require full locks. */ case AT_AddColumn: /* may rewrite heap, in some cases and visible * to SELECT */ case AT_SetAccessMethod: /* must rewrite heap */ case AT_SetTableSpace: /* must rewrite heap */ case AT_AlterColumnType: /* must rewrite heap */ cmd_lockmode = AccessExclusiveLock; break; /* * These subcommands may require addition of toast tables. If * we add a toast table to a table currently being scanned, we * might miss data added to the new toast table by concurrent * insert transactions. */ case AT_SetStorage: /* may add toast tables, see * ATRewriteCatalogs() */ cmd_lockmode = AccessExclusiveLock; break; /* * Removing constraints can affect SELECTs that have been * optimized assuming the constraint holds true. See also * CloneFkReferenced. */ case AT_DropConstraint: /* as DROP INDEX */ case AT_DropNotNull: /* may change some SQL plans */ cmd_lockmode = AccessExclusiveLock; break; /* * Subcommands that may be visible to concurrent SELECTs */ case AT_DropColumn: /* change visible to SELECT */ case AT_AddColumnToView: /* CREATE VIEW */ case AT_DropOids: /* used to equiv to DropColumn */ case AT_EnableAlwaysRule: /* may change SELECT rules */ case AT_EnableReplicaRule: /* may change SELECT rules */ case AT_EnableRule: /* may change SELECT rules */ case AT_DisableRule: /* may change SELECT rules */ cmd_lockmode = AccessExclusiveLock; break; /* * Changing owner may remove implicit SELECT privileges */ case AT_ChangeOwner: /* change visible to SELECT */ cmd_lockmode = AccessExclusiveLock; break; /* * Changing foreign table options may affect optimization. */ case AT_GenericOptions: case AT_AlterColumnGenericOptions: cmd_lockmode = AccessExclusiveLock; break; /* * These subcommands affect write operations only. */ case AT_EnableTrig: case AT_EnableAlwaysTrig: case AT_EnableReplicaTrig: case AT_EnableTrigAll: case AT_EnableTrigUser: case AT_DisableTrig: case AT_DisableTrigAll: case AT_DisableTrigUser: cmd_lockmode = ShareRowExclusiveLock; break; /* * These subcommands affect write operations only. XXX * Theoretically, these could be ShareRowExclusiveLock. */ case AT_ColumnDefault: case AT_CookedColumnDefault: case AT_AlterConstraint: case AT_AddIndex: /* from ADD CONSTRAINT */ case AT_AddIndexConstraint: case AT_ReplicaIdentity: case AT_SetNotNull: case AT_EnableRowSecurity: case AT_DisableRowSecurity: case AT_ForceRowSecurity: case AT_NoForceRowSecurity: case AT_AddIdentity: case AT_DropIdentity: case AT_SetIdentity: case AT_SetExpression: case AT_DropExpression: case AT_SetCompression: cmd_lockmode = AccessExclusiveLock; break; case AT_AddConstraint: case AT_ReAddConstraint: /* becomes AT_AddConstraint */ case AT_ReAddDomainConstraint: /* becomes AT_AddConstraint */ if (IsA(cmd->def, Constraint)) { Constraint *con = (Constraint *) cmd->def; switch (con->contype) { case CONSTR_EXCLUSION: case CONSTR_PRIMARY: case CONSTR_UNIQUE: /* * Cases essentially the same as CREATE INDEX. We * could reduce the lock strength to ShareLock if * we can work out how to allow concurrent catalog * updates. XXX Might be set down to * ShareRowExclusiveLock but requires further * analysis. */ cmd_lockmode = AccessExclusiveLock; break; case CONSTR_FOREIGN: /* * We add triggers to both tables when we add a * Foreign Key, so the lock level must be at least * as strong as CREATE TRIGGER. */ cmd_lockmode = ShareRowExclusiveLock; break; default: cmd_lockmode = AccessExclusiveLock; } } break; /* * These subcommands affect inheritance behaviour. Queries * started before us will continue to see the old inheritance * behaviour, while queries started after we commit will see * new behaviour. No need to prevent reads or writes to the * subtable while we hook it up though. Changing the TupDesc * may be a problem, so keep highest lock. */ case AT_AddInherit: case AT_DropInherit: cmd_lockmode = AccessExclusiveLock; break; /* * These subcommands affect implicit row type conversion. They * have affects similar to CREATE/DROP CAST on queries. don't * provide for invalidating parse trees as a result of such * changes, so we keep these at AccessExclusiveLock. */ case AT_AddOf: case AT_DropOf: cmd_lockmode = AccessExclusiveLock; break; /* * Only used by CREATE OR REPLACE VIEW which must conflict * with an SELECTs currently using the view. */ case AT_ReplaceRelOptions: cmd_lockmode = AccessExclusiveLock; break; /* * These subcommands affect general strategies for performance * and maintenance, though don't change the semantic results * from normal data reads and writes. Delaying an ALTER TABLE * behind currently active writes only delays the point where * the new strategy begins to take effect, so there is no * benefit in waiting. In this case the minimum restriction * applies: we don't currently allow concurrent catalog * updates. */ case AT_SetStatistics: /* Uses MVCC in getTableAttrs() */ case AT_ClusterOn: /* Uses MVCC in getIndexes() */ case AT_DropCluster: /* Uses MVCC in getIndexes() */ case AT_SetOptions: /* Uses MVCC in getTableAttrs() */ case AT_ResetOptions: /* Uses MVCC in getTableAttrs() */ cmd_lockmode = ShareUpdateExclusiveLock; break; case AT_SetLogged: case AT_SetUnLogged: cmd_lockmode = AccessExclusiveLock; break; case AT_ValidateConstraint: /* Uses MVCC in getConstraints() */ cmd_lockmode = ShareUpdateExclusiveLock; break; /* * Rel options are more complex than first appears. Options * are set here for tables, views and indexes; for historical * reasons these can all be used with ALTER TABLE, so we can't * decide between them using the basic grammar. */ case AT_SetRelOptions: /* Uses MVCC in getIndexes() and * getTables() */ case AT_ResetRelOptions: /* Uses MVCC in getIndexes() and * getTables() */ cmd_lockmode = AlterTableGetRelOptionsLockLevel((List *) cmd->def); break; case AT_AttachPartition: cmd_lockmode = ShareUpdateExclusiveLock; break; case AT_DetachPartition: if (((PartitionCmd *) cmd->def)->concurrent) cmd_lockmode = ShareUpdateExclusiveLock; else cmd_lockmode = AccessExclusiveLock; break; case AT_DetachPartitionFinalize: cmd_lockmode = ShareUpdateExclusiveLock; break; case AT_MergePartitions: case AT_SplitPartition: cmd_lockmode = AccessExclusiveLock; break; default: /* oops */ elog(ERROR, "unrecognized alter table type: %d", (int) cmd->subtype); break; } /* * Take the greatest lockmode from any subcommand */ if (cmd_lockmode > lockmode) lockmode = cmd_lockmode; } return lockmode; } /* * ATController provides top level control over the phases. * * parsetree is passed in to allow it to be passed to event triggers * when requested. */ static void ATController(AlterTableStmt *parsetree, Relation rel, List *cmds, bool recurse, LOCKMODE lockmode, AlterTableUtilityContext *context) { List *wqueue = NIL; ListCell *lcmd; /* Phase 1: preliminary examination of commands, create work queue */ foreach(lcmd, cmds) { AlterTableCmd *cmd = (AlterTableCmd *) lfirst(lcmd); ATPrepCmd(&wqueue, rel, cmd, recurse, false, lockmode, context); } /* Close the relation, but keep lock until commit */ relation_close(rel, NoLock); /* Phase 2: update system catalogs */ ATRewriteCatalogs(&wqueue, lockmode, context); /* Phase 3: scan/rewrite tables as needed, and run afterStmts */ ATRewriteTables(parsetree, &wqueue, lockmode, context); } /* * ATPrepCmd * * Traffic cop for ALTER TABLE Phase 1 operations, including simple * recursion and permission checks. * * Caller must have acquired appropriate lock type on relation already. * This lock should be held until commit. */ static void ATPrepCmd(List **wqueue, Relation rel, AlterTableCmd *cmd, bool recurse, bool recursing, LOCKMODE lockmode, AlterTableUtilityContext *context) { AlteredTableInfo *tab; AlterTablePass pass = AT_PASS_UNSET; /* Find or create work queue entry for this table */ tab = ATGetQueueEntry(wqueue, rel); /* * Disallow any ALTER TABLE other than ALTER TABLE DETACH FINALIZE on * partitions that are pending detach. */ if (rel->rd_rel->relispartition && cmd->subtype != AT_DetachPartitionFinalize && PartitionHasPendingDetach(RelationGetRelid(rel))) ereport(ERROR, errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("cannot alter partition \"%s\" with an incomplete detach", RelationGetRelationName(rel)), errhint("Use ALTER TABLE ... DETACH PARTITION ... FINALIZE to complete the pending detach operation.")); /* * Copy the original subcommand for each table, so we can scribble on it. * This avoids conflicts when different child tables need to make * different parse transformations (for example, the same column may have * different column numbers in different children). */ cmd = copyObject(cmd); /* * Do permissions and relkind checking, recursion to child tables if * needed, and any additional phase-1 processing needed. (But beware of * adding any processing that looks at table details that another * subcommand could change. In some cases we reject multiple subcommands * that could try to change the same state in contrary ways.) */ switch (cmd->subtype) { case AT_AddColumn: /* ADD COLUMN */ ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_PARTITIONED_TABLE | ATT_COMPOSITE_TYPE | ATT_FOREIGN_TABLE); ATPrepAddColumn(wqueue, rel, recurse, recursing, false, cmd, lockmode, context); /* Recursion occurs during execution phase */ pass = AT_PASS_ADD_COL; break; case AT_AddColumnToView: /* add column via CREATE OR REPLACE VIEW */ ATSimplePermissions(cmd->subtype, rel, ATT_VIEW); ATPrepAddColumn(wqueue, rel, recurse, recursing, true, cmd, lockmode, context); /* Recursion occurs during execution phase */ pass = AT_PASS_ADD_COL; break; case AT_ColumnDefault: /* ALTER COLUMN DEFAULT */ /* * We allow defaults on views so that INSERT into a view can have * default-ish behavior. This works because the rewriter * substitutes default values into INSERTs before it expands * rules. */ ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_PARTITIONED_TABLE | ATT_VIEW | ATT_FOREIGN_TABLE); ATSimpleRecursion(wqueue, rel, cmd, recurse, lockmode, context); /* No command-specific prep needed */ pass = cmd->def ? AT_PASS_ADD_OTHERCONSTR : AT_PASS_DROP; break; case AT_CookedColumnDefault: /* add a pre-cooked default */ /* This is currently used only in CREATE TABLE */ /* (so the permission check really isn't necessary) */ ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_PARTITIONED_TABLE | ATT_FOREIGN_TABLE); /* This command never recurses */ pass = AT_PASS_ADD_OTHERCONSTR; break; case AT_AddIdentity: ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_PARTITIONED_TABLE | ATT_VIEW | ATT_FOREIGN_TABLE); /* Set up recursion for phase 2; no other prep needed */ if (recurse) cmd->recurse = true; pass = AT_PASS_ADD_OTHERCONSTR; break; case AT_SetIdentity: ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_PARTITIONED_TABLE | ATT_VIEW | ATT_FOREIGN_TABLE); /* Set up recursion for phase 2; no other prep needed */ if (recurse) cmd->recurse = true; /* This should run after AddIdentity, so do it in MISC pass */ pass = AT_PASS_MISC; break; case AT_DropIdentity: ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_PARTITIONED_TABLE | ATT_VIEW | ATT_FOREIGN_TABLE); /* Set up recursion for phase 2; no other prep needed */ if (recurse) cmd->recurse = true; pass = AT_PASS_DROP; break; case AT_DropNotNull: /* ALTER COLUMN DROP NOT NULL */ ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_PARTITIONED_TABLE | ATT_FOREIGN_TABLE); /* Set up recursion for phase 2; no other prep needed */ if (recurse) cmd->recurse = true; pass = AT_PASS_DROP; break; case AT_SetNotNull: /* ALTER COLUMN SET NOT NULL */ ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_PARTITIONED_TABLE | ATT_FOREIGN_TABLE); /* Set up recursion for phase 2; no other prep needed */ if (recurse) cmd->recurse = true; pass = AT_PASS_COL_ATTRS; break; case AT_SetExpression: /* ALTER COLUMN SET EXPRESSION */ ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_PARTITIONED_TABLE | ATT_FOREIGN_TABLE); ATSimpleRecursion(wqueue, rel, cmd, recurse, lockmode, context); pass = AT_PASS_SET_EXPRESSION; break; case AT_DropExpression: /* ALTER COLUMN DROP EXPRESSION */ ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_PARTITIONED_TABLE | ATT_FOREIGN_TABLE); ATSimpleRecursion(wqueue, rel, cmd, recurse, lockmode, context); ATPrepDropExpression(rel, cmd, recurse, recursing, lockmode); pass = AT_PASS_DROP; break; case AT_SetStatistics: /* ALTER COLUMN SET STATISTICS */ ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_PARTITIONED_TABLE | ATT_MATVIEW | ATT_INDEX | ATT_PARTITIONED_INDEX | ATT_FOREIGN_TABLE); ATSimpleRecursion(wqueue, rel, cmd, recurse, lockmode, context); /* No command-specific prep needed */ pass = AT_PASS_MISC; break; case AT_SetOptions: /* ALTER COLUMN SET ( options ) */ case AT_ResetOptions: /* ALTER COLUMN RESET ( options ) */ ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_PARTITIONED_TABLE | ATT_MATVIEW | ATT_FOREIGN_TABLE); /* This command never recurses */ pass = AT_PASS_MISC; break; case AT_SetStorage: /* ALTER COLUMN SET STORAGE */ ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_PARTITIONED_TABLE | ATT_MATVIEW | ATT_FOREIGN_TABLE); ATSimpleRecursion(wqueue, rel, cmd, recurse, lockmode, context); /* No command-specific prep needed */ pass = AT_PASS_MISC; break; case AT_SetCompression: /* ALTER COLUMN SET COMPRESSION */ ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_PARTITIONED_TABLE | ATT_MATVIEW); /* This command never recurses */ /* No command-specific prep needed */ pass = AT_PASS_MISC; break; case AT_DropColumn: /* DROP COLUMN */ ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_PARTITIONED_TABLE | ATT_COMPOSITE_TYPE | ATT_FOREIGN_TABLE); ATPrepDropColumn(wqueue, rel, recurse, recursing, cmd, lockmode, context); /* Recursion occurs during execution phase */ pass = AT_PASS_DROP; break; case AT_AddIndex: /* ADD INDEX */ ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_PARTITIONED_TABLE); /* This command never recurses */ /* No command-specific prep needed */ pass = AT_PASS_ADD_INDEX; break; case AT_AddConstraint: /* ADD CONSTRAINT */ ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_PARTITIONED_TABLE | ATT_FOREIGN_TABLE); ATPrepAddPrimaryKey(wqueue, rel, cmd, recurse, lockmode, context); if (recurse) { /* recurses at exec time; lock descendants and set flag */ (void) find_all_inheritors(RelationGetRelid(rel), lockmode, NULL); cmd->recurse = true; } pass = AT_PASS_ADD_CONSTR; break; case AT_AddIndexConstraint: /* ADD CONSTRAINT USING INDEX */ ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_PARTITIONED_TABLE); /* This command never recurses */ /* No command-specific prep needed */ pass = AT_PASS_ADD_INDEXCONSTR; break; case AT_DropConstraint: /* DROP CONSTRAINT */ ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_PARTITIONED_TABLE | ATT_FOREIGN_TABLE); ATCheckPartitionsNotInUse(rel, lockmode); /* Other recursion occurs during execution phase */ /* No command-specific prep needed except saving recurse flag */ if (recurse) cmd->recurse = true; pass = AT_PASS_DROP; break; case AT_AlterColumnType: /* ALTER COLUMN TYPE */ ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_PARTITIONED_TABLE | ATT_COMPOSITE_TYPE | ATT_FOREIGN_TABLE); /* See comments for ATPrepAlterColumnType */ cmd = ATParseTransformCmd(wqueue, tab, rel, cmd, recurse, lockmode, AT_PASS_UNSET, context); Assert(cmd != NULL); /* Performs own recursion */ ATPrepAlterColumnType(wqueue, tab, rel, recurse, recursing, cmd, lockmode, context); pass = AT_PASS_ALTER_TYPE; break; case AT_AlterColumnGenericOptions: ATSimplePermissions(cmd->subtype, rel, ATT_FOREIGN_TABLE); /* This command never recurses */ /* No command-specific prep needed */ pass = AT_PASS_MISC; break; case AT_ChangeOwner: /* ALTER OWNER */ /* This command never recurses */ /* No command-specific prep needed */ pass = AT_PASS_MISC; break; case AT_ClusterOn: /* CLUSTER ON */ case AT_DropCluster: /* SET WITHOUT CLUSTER */ ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_MATVIEW); /* These commands never recurse */ /* No command-specific prep needed */ pass = AT_PASS_MISC; break; case AT_SetLogged: /* SET LOGGED */ case AT_SetUnLogged: /* SET UNLOGGED */ ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_SEQUENCE); if (tab->chgPersistence) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot change persistence setting twice"))); ATPrepChangePersistence(tab, rel, cmd->subtype == AT_SetLogged); pass = AT_PASS_MISC; break; case AT_DropOids: /* SET WITHOUT OIDS */ ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_PARTITIONED_TABLE | ATT_FOREIGN_TABLE); pass = AT_PASS_DROP; break; case AT_SetAccessMethod: /* SET ACCESS METHOD */ ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_PARTITIONED_TABLE | ATT_MATVIEW); /* check if another access method change was already requested */ if (tab->chgAccessMethod) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot have multiple SET ACCESS METHOD subcommands"))); ATPrepSetAccessMethod(tab, rel, cmd->name); pass = AT_PASS_MISC; /* does not matter; no work in Phase 2 */ break; case AT_SetTableSpace: /* SET TABLESPACE */ ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_PARTITIONED_TABLE | ATT_MATVIEW | ATT_INDEX | ATT_PARTITIONED_INDEX); /* This command never recurses */ ATPrepSetTableSpace(tab, rel, cmd->name, lockmode); pass = AT_PASS_MISC; /* doesn't actually matter */ break; case AT_SetRelOptions: /* SET (...) */ case AT_ResetRelOptions: /* RESET (...) */ case AT_ReplaceRelOptions: /* reset them all, then set just these */ ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_PARTITIONED_TABLE | ATT_VIEW | ATT_MATVIEW | ATT_INDEX); /* This command never recurses */ /* No command-specific prep needed */ pass = AT_PASS_MISC; break; case AT_AddInherit: /* INHERIT */ ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_FOREIGN_TABLE); /* This command never recurses */ ATPrepChangeInherit(rel); pass = AT_PASS_MISC; break; case AT_DropInherit: /* NO INHERIT */ ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_FOREIGN_TABLE); /* This command never recurses */ ATPrepChangeInherit(rel); pass = AT_PASS_MISC; break; case AT_AlterConstraint: /* ALTER CONSTRAINT */ ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_PARTITIONED_TABLE); /* Recursion occurs during execution phase */ if (recurse) cmd->recurse = true; pass = AT_PASS_MISC; break; case AT_ValidateConstraint: /* VALIDATE CONSTRAINT */ ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_PARTITIONED_TABLE | ATT_FOREIGN_TABLE); /* Recursion occurs during execution phase */ /* No command-specific prep needed except saving recurse flag */ if (recurse) cmd->recurse = true; pass = AT_PASS_MISC; break; case AT_ReplicaIdentity: /* REPLICA IDENTITY ... */ ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_PARTITIONED_TABLE | ATT_MATVIEW); pass = AT_PASS_MISC; /* This command never recurses */ /* No command-specific prep needed */ break; case AT_EnableTrig: /* ENABLE TRIGGER variants */ case AT_EnableAlwaysTrig: case AT_EnableReplicaTrig: case AT_EnableTrigAll: case AT_EnableTrigUser: case AT_DisableTrig: /* DISABLE TRIGGER variants */ case AT_DisableTrigAll: case AT_DisableTrigUser: ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_PARTITIONED_TABLE | ATT_FOREIGN_TABLE); /* Set up recursion for phase 2; no other prep needed */ if (recurse) cmd->recurse = true; pass = AT_PASS_MISC; break; case AT_EnableRule: /* ENABLE/DISABLE RULE variants */ case AT_EnableAlwaysRule: case AT_EnableReplicaRule: case AT_DisableRule: case AT_AddOf: /* OF */ case AT_DropOf: /* NOT OF */ case AT_EnableRowSecurity: case AT_DisableRowSecurity: case AT_ForceRowSecurity: case AT_NoForceRowSecurity: ATSimplePermissions(cmd->subtype, rel, ATT_TABLE | ATT_PARTITIONED_TABLE); /* These commands never recurse */ /* No command-specific prep needed */ pass = AT_PASS_MISC; break; case AT_GenericOptions: ATSimplePermissions(cmd->subtype, rel, ATT_FOREIGN_TABLE); /* No command-specific prep needed */ pass = AT_PASS_MISC; break; case AT_AttachPartition: ATSimplePermissions(cmd->subtype, rel, ATT_PARTITIONED_TABLE | ATT_PARTITIONED_INDEX); /* No command-specific prep needed */ pass = AT_PASS_MISC; break; case AT_DetachPartition: ATSimplePermissions(cmd->subtype, rel, ATT_PARTITIONED_TABLE); /* No command-specific prep needed */ pass = AT_PASS_MISC; break; case AT_DetachPartitionFinalize: ATSimplePermissions(cmd->subtype, rel, ATT_PARTITIONED_TABLE); /* No command-specific prep needed */ pass = AT_PASS_MISC; break; case AT_MergePartitions: case AT_SplitPartition: ATSimplePermissions(cmd->subtype, rel, ATT_PARTITIONED_TABLE); /* No command-specific prep needed */ pass = AT_PASS_MISC; break; default: /* oops */ elog(ERROR, "unrecognized alter table type: %d", (int) cmd->subtype); pass = AT_PASS_UNSET; /* keep compiler quiet */ break; } Assert(pass > AT_PASS_UNSET); /* Add the subcommand to the appropriate list for phase 2 */ tab->subcmds[pass] = lappend(tab->subcmds[pass], cmd); } /* * ATRewriteCatalogs * * Traffic cop for ALTER TABLE Phase 2 operations. Subcommands are * dispatched in a "safe" execution order (designed to avoid unnecessary * conflicts). */ static void ATRewriteCatalogs(List **wqueue, LOCKMODE lockmode, AlterTableUtilityContext *context) { ListCell *ltab; /* * We process all the tables "in parallel", one pass at a time. This is * needed because we may have to propagate work from one table to another * (specifically, ALTER TYPE on a foreign key's PK has to dispatch the * re-adding of the foreign key constraint to the other table). Work can * only be propagated into later passes, however. */ for (AlterTablePass pass = 0; pass < AT_NUM_PASSES; pass++) { /* Go through each table that needs to be processed */ foreach(ltab, *wqueue) { AlteredTableInfo *tab = (AlteredTableInfo *) lfirst(ltab); List *subcmds = tab->subcmds[pass]; ListCell *lcmd; if (subcmds == NIL) continue; /* * Open the relation and store it in tab. This allows subroutines * close and reopen, if necessary. Appropriate lock was obtained * by phase 1, needn't get it again. */ tab->rel = relation_open(tab->relid, NoLock); foreach(lcmd, subcmds) ATExecCmd(wqueue, tab, lfirst_node(AlterTableCmd, lcmd), lockmode, pass, context); /* * After the ALTER TYPE or SET EXPRESSION pass, do cleanup work * (this is not done in ATExecAlterColumnType since it should be * done only once if multiple columns of a table are altered). */ if (pass == AT_PASS_ALTER_TYPE || pass == AT_PASS_SET_EXPRESSION) ATPostAlterTypeCleanup(wqueue, tab, lockmode); if (tab->rel) { relation_close(tab->rel, NoLock); tab->rel = NULL; } } } /* Check to see if a toast table must be added. */ foreach(ltab, *wqueue) { AlteredTableInfo *tab = (AlteredTableInfo *) lfirst(ltab); /* * If the table is source table of ATTACH PARTITION command, we did * not modify anything about it that will change its toasting * requirement, so no need to check. */ if (((tab->relkind == RELKIND_RELATION || tab->relkind == RELKIND_PARTITIONED_TABLE) && tab->partition_constraint == NULL) || tab->relkind == RELKIND_MATVIEW) AlterTableCreateToastTable(tab->relid, (Datum) 0, lockmode); } } /* * ATExecCmd: dispatch a subcommand to appropriate execution routine */ static void ATExecCmd(List **wqueue, AlteredTableInfo *tab, AlterTableCmd *cmd, LOCKMODE lockmode, AlterTablePass cur_pass, AlterTableUtilityContext *context) { ObjectAddress address = InvalidObjectAddress; Relation rel = tab->rel; switch (cmd->subtype) { case AT_AddColumn: /* ADD COLUMN */ case AT_AddColumnToView: /* add column via CREATE OR REPLACE VIEW */ address = ATExecAddColumn(wqueue, tab, rel, &cmd, cmd->recurse, false, lockmode, cur_pass, context); break; case AT_ColumnDefault: /* ALTER COLUMN DEFAULT */ address = ATExecColumnDefault(rel, cmd->name, cmd->def, lockmode); break; case AT_CookedColumnDefault: /* add a pre-cooked default */ address = ATExecCookedColumnDefault(rel, cmd->num, cmd->def); break; case AT_AddIdentity: cmd = ATParseTransformCmd(wqueue, tab, rel, cmd, false, lockmode, cur_pass, context); Assert(cmd != NULL); address = ATExecAddIdentity(rel, cmd->name, cmd->def, lockmode, cmd->recurse, false); break; case AT_SetIdentity: cmd = ATParseTransformCmd(wqueue, tab, rel, cmd, false, lockmode, cur_pass, context); Assert(cmd != NULL); address = ATExecSetIdentity(rel, cmd->name, cmd->def, lockmode, cmd->recurse, false); break; case AT_DropIdentity: address = ATExecDropIdentity(rel, cmd->name, cmd->missing_ok, lockmode, cmd->recurse, false); break; case AT_DropNotNull: /* ALTER COLUMN DROP NOT NULL */ address = ATExecDropNotNull(rel, cmd->name, cmd->recurse, lockmode); break; case AT_SetNotNull: /* ALTER COLUMN SET NOT NULL */ address = ATExecSetNotNull(wqueue, rel, NULL, cmd->name, cmd->recurse, false, lockmode); break; case AT_SetExpression: address = ATExecSetExpression(tab, rel, cmd->name, cmd->def, lockmode); break; case AT_DropExpression: address = ATExecDropExpression(rel, cmd->name, cmd->missing_ok, lockmode); break; case AT_SetStatistics: /* ALTER COLUMN SET STATISTICS */ address = ATExecSetStatistics(rel, cmd->name, cmd->num, cmd->def, lockmode); break; case AT_SetOptions: /* ALTER COLUMN SET ( options ) */ address = ATExecSetOptions(rel, cmd->name, cmd->def, false, lockmode); break; case AT_ResetOptions: /* ALTER COLUMN RESET ( options ) */ address = ATExecSetOptions(rel, cmd->name, cmd->def, true, lockmode); break; case AT_SetStorage: /* ALTER COLUMN SET STORAGE */ address = ATExecSetStorage(rel, cmd->name, cmd->def, lockmode); break; case AT_SetCompression: /* ALTER COLUMN SET COMPRESSION */ address = ATExecSetCompression(rel, cmd->name, cmd->def, lockmode); break; case AT_DropColumn: /* DROP COLUMN */ address = ATExecDropColumn(wqueue, rel, cmd->name, cmd->behavior, cmd->recurse, false, cmd->missing_ok, lockmode, NULL); break; case AT_AddIndex: /* ADD INDEX */ address = ATExecAddIndex(tab, rel, (IndexStmt *) cmd->def, false, lockmode); break; case AT_ReAddIndex: /* ADD INDEX */ address = ATExecAddIndex(tab, rel, (IndexStmt *) cmd->def, true, lockmode); break; case AT_ReAddStatistics: /* ADD STATISTICS */ address = ATExecAddStatistics(tab, rel, (CreateStatsStmt *) cmd->def, true, lockmode); break; case AT_AddConstraint: /* ADD CONSTRAINT */ /* Transform the command only during initial examination */ if (cur_pass == AT_PASS_ADD_CONSTR) cmd = ATParseTransformCmd(wqueue, tab, rel, cmd, cmd->recurse, lockmode, cur_pass, context); /* Depending on constraint type, might be no more work to do now */ if (cmd != NULL) address = ATExecAddConstraint(wqueue, tab, rel, (Constraint *) cmd->def, cmd->recurse, false, lockmode); break; case AT_ReAddConstraint: /* Re-add pre-existing check constraint */ address = ATExecAddConstraint(wqueue, tab, rel, (Constraint *) cmd->def, true, true, lockmode); break; case AT_ReAddDomainConstraint: /* Re-add pre-existing domain check * constraint */ address = AlterDomainAddConstraint(((AlterDomainStmt *) cmd->def)->typeName, ((AlterDomainStmt *) cmd->def)->def, NULL, true); break; case AT_ReAddComment: /* Re-add existing comment */ address = CommentObject((CommentStmt *) cmd->def); break; case AT_AddIndexConstraint: /* ADD CONSTRAINT USING INDEX */ address = ATExecAddIndexConstraint(tab, rel, (IndexStmt *) cmd->def, lockmode); break; case AT_AlterConstraint: /* ALTER CONSTRAINT */ address = ATExecAlterConstraint(wqueue, rel, castNode(ATAlterConstraint, cmd->def), cmd->recurse, lockmode); break; case AT_ValidateConstraint: /* VALIDATE CONSTRAINT */ address = ATExecValidateConstraint(wqueue, rel, cmd->name, cmd->recurse, false, lockmode); break; case AT_DropConstraint: /* DROP CONSTRAINT */ ATExecDropConstraint(rel, cmd->name, cmd->behavior, cmd->recurse, cmd->missing_ok, lockmode); break; case AT_AlterColumnType: /* ALTER COLUMN TYPE */ /* parse transformation was done earlier */ address = ATExecAlterColumnType(tab, rel, cmd, lockmode); break; case AT_AlterColumnGenericOptions: /* ALTER COLUMN OPTIONS */ address = ATExecAlterColumnGenericOptions(rel, cmd->name, (List *) cmd->def, lockmode); break; case AT_ChangeOwner: /* ALTER OWNER */ ATExecChangeOwner(RelationGetRelid(rel), get_rolespec_oid(cmd->newowner, false), false, lockmode); break; case AT_ClusterOn: /* CLUSTER ON */ address = ATExecClusterOn(rel, cmd->name, lockmode); break; case AT_DropCluster: /* SET WITHOUT CLUSTER */ ATExecDropCluster(rel, lockmode); break; case AT_SetLogged: /* SET LOGGED */ case AT_SetUnLogged: /* SET UNLOGGED */ break; case AT_DropOids: /* SET WITHOUT OIDS */ /* nothing to do here, oid columns don't exist anymore */ break; case AT_SetAccessMethod: /* SET ACCESS METHOD */ /* * Only do this for partitioned tables, for which this is just a * catalog change. Tables with storage are handled by Phase 3. */ if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE && tab->chgAccessMethod) ATExecSetAccessMethodNoStorage(rel, tab->newAccessMethod); break; case AT_SetTableSpace: /* SET TABLESPACE */ /* * Only do this for partitioned tables and indexes, for which this * is just a catalog change. Other relation types which have * storage are handled by Phase 3. */ if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE || rel->rd_rel->relkind == RELKIND_PARTITIONED_INDEX) ATExecSetTableSpaceNoStorage(rel, tab->newTableSpace); break; case AT_SetRelOptions: /* SET (...) */ case AT_ResetRelOptions: /* RESET (...) */ case AT_ReplaceRelOptions: /* replace entire option list */ ATExecSetRelOptions(rel, (List *) cmd->def, cmd->subtype, lockmode); break; case AT_EnableTrig: /* ENABLE TRIGGER name */ ATExecEnableDisableTrigger(rel, cmd->name, TRIGGER_FIRES_ON_ORIGIN, false, cmd->recurse, lockmode); break; case AT_EnableAlwaysTrig: /* ENABLE ALWAYS TRIGGER name */ ATExecEnableDisableTrigger(rel, cmd->name, TRIGGER_FIRES_ALWAYS, false, cmd->recurse, lockmode); break; case AT_EnableReplicaTrig: /* ENABLE REPLICA TRIGGER name */ ATExecEnableDisableTrigger(rel, cmd->name, TRIGGER_FIRES_ON_REPLICA, false, cmd->recurse, lockmode); break; case AT_DisableTrig: /* DISABLE TRIGGER name */ ATExecEnableDisableTrigger(rel, cmd->name, TRIGGER_DISABLED, false, cmd->recurse, lockmode); break; case AT_EnableTrigAll: /* ENABLE TRIGGER ALL */ ATExecEnableDisableTrigger(rel, NULL, TRIGGER_FIRES_ON_ORIGIN, false, cmd->recurse, lockmode); break; case AT_DisableTrigAll: /* DISABLE TRIGGER ALL */ ATExecEnableDisableTrigger(rel, NULL, TRIGGER_DISABLED, false, cmd->recurse, lockmode); break; case AT_EnableTrigUser: /* ENABLE TRIGGER USER */ ATExecEnableDisableTrigger(rel, NULL, TRIGGER_FIRES_ON_ORIGIN, true, cmd->recurse, lockmode); break; case AT_DisableTrigUser: /* DISABLE TRIGGER USER */ ATExecEnableDisableTrigger(rel, NULL, TRIGGER_DISABLED, true, cmd->recurse, lockmode); break; case AT_EnableRule: /* ENABLE RULE name */ ATExecEnableDisableRule(rel, cmd->name, RULE_FIRES_ON_ORIGIN, lockmode); break; case AT_EnableAlwaysRule: /* ENABLE ALWAYS RULE name */ ATExecEnableDisableRule(rel, cmd->name, RULE_FIRES_ALWAYS, lockmode); break; case AT_EnableReplicaRule: /* ENABLE REPLICA RULE name */ ATExecEnableDisableRule(rel, cmd->name, RULE_FIRES_ON_REPLICA, lockmode); break; case AT_DisableRule: /* DISABLE RULE name */ ATExecEnableDisableRule(rel, cmd->name, RULE_DISABLED, lockmode); break; case AT_AddInherit: address = ATExecAddInherit(rel, (RangeVar *) cmd->def, lockmode); break; case AT_DropInherit: address = ATExecDropInherit(rel, (RangeVar *) cmd->def, lockmode); break; case AT_AddOf: address = ATExecAddOf(rel, (TypeName *) cmd->def, lockmode); break; case AT_DropOf: ATExecDropOf(rel, lockmode); break; case AT_ReplicaIdentity: ATExecReplicaIdentity(rel, (ReplicaIdentityStmt *) cmd->def, lockmode); break; case AT_EnableRowSecurity: ATExecSetRowSecurity(rel, true); break; case AT_DisableRowSecurity: ATExecSetRowSecurity(rel, false); break; case AT_ForceRowSecurity: ATExecForceNoForceRowSecurity(rel, true); break; case AT_NoForceRowSecurity: ATExecForceNoForceRowSecurity(rel, false); break; case AT_GenericOptions: ATExecGenericOptions(rel, (List *) cmd->def); break; case AT_AttachPartition: cmd = ATParseTransformCmd(wqueue, tab, rel, cmd, false, lockmode, cur_pass, context); Assert(cmd != NULL); if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) address = ATExecAttachPartition(wqueue, rel, (PartitionCmd *) cmd->def, context); else address = ATExecAttachPartitionIdx(wqueue, rel, ((PartitionCmd *) cmd->def)->name); break; case AT_DetachPartition: cmd = ATParseTransformCmd(wqueue, tab, rel, cmd, false, lockmode, cur_pass, context); Assert(cmd != NULL); /* ATPrepCmd ensures it must be a table */ Assert(rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE); address = ATExecDetachPartition(wqueue, tab, rel, ((PartitionCmd *) cmd->def)->name, ((PartitionCmd *) cmd->def)->concurrent); break; case AT_DetachPartitionFinalize: address = ATExecDetachPartitionFinalize(rel, ((PartitionCmd *) cmd->def)->name); break; case AT_MergePartitions: cmd = ATParseTransformCmd(wqueue, tab, rel, cmd, false, lockmode, cur_pass, context); Assert(cmd != NULL); Assert(rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE); ATExecMergePartitions(wqueue, tab, rel, (PartitionCmd *) cmd->def, context); break; case AT_SplitPartition: cmd = ATParseTransformCmd(wqueue, tab, rel, cmd, false, lockmode, cur_pass, context); Assert(cmd != NULL); Assert(rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE); ATExecSplitPartition(wqueue, tab, rel, (PartitionCmd *) cmd->def, context); break; default: /* oops */ elog(ERROR, "unrecognized alter table type: %d", (int) cmd->subtype); break; } /* * Report the subcommand to interested event triggers. */ if (cmd) EventTriggerCollectAlterTableSubcmd((Node *) cmd, address); /* * Bump the command counter to ensure the next subcommand in the sequence * can see the changes so far */ CommandCounterIncrement(); } /* * ATParseTransformCmd: perform parse transformation for one subcommand * * Returns the transformed subcommand tree, if there is one, else NULL. * * The parser may hand back additional AlterTableCmd(s) and/or other * utility statements, either before or after the original subcommand. * Other AlterTableCmds are scheduled into the appropriate slot of the * AlteredTableInfo (they had better be for later passes than the current one). * Utility statements that are supposed to happen before the AlterTableCmd * are executed immediately. Those that are supposed to happen afterwards * are added to the tab->afterStmts list to be done at the very end. */ static AlterTableCmd * ATParseTransformCmd(List **wqueue, AlteredTableInfo *tab, Relation rel, AlterTableCmd *cmd, bool recurse, LOCKMODE lockmode, AlterTablePass cur_pass, AlterTableUtilityContext *context) { AlterTableCmd *newcmd = NULL; AlterTableStmt *atstmt = makeNode(AlterTableStmt); List *beforeStmts; List *afterStmts; ListCell *lc; /* Gin up an AlterTableStmt with just this subcommand and this table */ atstmt->relation = makeRangeVar(get_namespace_name(RelationGetNamespace(rel)), pstrdup(RelationGetRelationName(rel)), -1); atstmt->relation->inh = recurse; atstmt->cmds = list_make1(cmd); atstmt->objtype = OBJECT_TABLE; /* needn't be picky here */ atstmt->missing_ok = false; /* Transform the AlterTableStmt */ atstmt = transformAlterTableStmt(RelationGetRelid(rel), atstmt, context->queryString, &beforeStmts, &afterStmts); /* Execute any statements that should happen before these subcommand(s) */ foreach(lc, beforeStmts) { Node *stmt = (Node *) lfirst(lc); ProcessUtilityForAlterTable(stmt, context); CommandCounterIncrement(); } /* Examine the transformed subcommands and schedule them appropriately */ foreach(lc, atstmt->cmds) { AlterTableCmd *cmd2 = lfirst_node(AlterTableCmd, lc); AlterTablePass pass; /* * This switch need only cover the subcommand types that can be added * by parse_utilcmd.c; otherwise, we'll use the default strategy of * executing the subcommand immediately, as a substitute for the * original subcommand. (Note, however, that this does cause * AT_AddConstraint subcommands to be rescheduled into later passes, * which is important for index and foreign key constraints.) * * We assume we needn't do any phase-1 checks for added subcommands. */ switch (cmd2->subtype) { case AT_AddIndex: pass = AT_PASS_ADD_INDEX; break; case AT_AddIndexConstraint: pass = AT_PASS_ADD_INDEXCONSTR; break; case AT_AddConstraint: /* Recursion occurs during execution phase */ if (recurse) cmd2->recurse = true; switch (castNode(Constraint, cmd2->def)->contype) { case CONSTR_NOTNULL: pass = AT_PASS_COL_ATTRS; break; case CONSTR_PRIMARY: case CONSTR_UNIQUE: case CONSTR_EXCLUSION: pass = AT_PASS_ADD_INDEXCONSTR; break; default: pass = AT_PASS_ADD_OTHERCONSTR; break; } break; case AT_AlterColumnGenericOptions: /* This command never recurses */ /* No command-specific prep needed */ pass = AT_PASS_MISC; break; default: pass = cur_pass; break; } if (pass < cur_pass) { /* Cannot schedule into a pass we already finished */ elog(ERROR, "ALTER TABLE scheduling failure: too late for pass %d", pass); } else if (pass > cur_pass) { /* OK, queue it up for later */ tab->subcmds[pass] = lappend(tab->subcmds[pass], cmd2); } else { /* * We should see at most one subcommand for the current pass, * which is the transformed version of the original subcommand. */ if (newcmd == NULL && cmd->subtype == cmd2->subtype) { /* Found the transformed version of our subcommand */ newcmd = cmd2; } else elog(ERROR, "ALTER TABLE scheduling failure: bogus item for pass %d", pass); } } /* Queue up any after-statements to happen at the end */ tab->afterStmts = list_concat(tab->afterStmts, afterStmts); return newcmd; } /* * ATRewriteTables: ALTER TABLE phase 3 */ static void ATRewriteTables(AlterTableStmt *parsetree, List **wqueue, LOCKMODE lockmode, AlterTableUtilityContext *context) { ListCell *ltab; /* Go through each table that needs to be checked or rewritten */ foreach(ltab, *wqueue) { AlteredTableInfo *tab = (AlteredTableInfo *) lfirst(ltab); /* Relations without storage may be ignored here */ if (!RELKIND_HAS_STORAGE(tab->relkind)) continue; /* * If we change column data types, the operation has to be propagated * to tables that use this table's rowtype as a column type. * tab->newvals will also be non-NULL in the case where we're adding a * column with a default. We choose to forbid that case as well, * since composite types might eventually support defaults. * * (Eventually we'll probably need to check for composite type * dependencies even when we're just scanning the table without a * rewrite, but at the moment a composite type does not enforce any * constraints, so it's not necessary/appropriate to enforce them just * during ALTER.) */ if (tab->newvals != NIL || tab->rewrite > 0) { Relation rel; rel = table_open(tab->relid, NoLock); find_composite_type_dependencies(rel->rd_rel->reltype, rel, NULL); table_close(rel, NoLock); } /* * We only need to rewrite the table if at least one column needs to * be recomputed, or we are changing its persistence or access method. * * There are two reasons for requiring a rewrite when changing * persistence: on one hand, we need to ensure that the buffers * belonging to each of the two relations are marked with or without * BM_PERMANENT properly. On the other hand, since rewriting creates * and assigns a new relfilenumber, we automatically create or drop an * init fork for the relation as appropriate. */ if (tab->rewrite > 0 && tab->relkind != RELKIND_SEQUENCE) { /* Build a temporary relation and copy data */ Relation OldHeap; Oid OIDNewHeap; Oid NewAccessMethod; Oid NewTableSpace; char persistence; OldHeap = table_open(tab->relid, NoLock); /* * We don't support rewriting of system catalogs; there are too * many corner cases and too little benefit. In particular this * is certainly not going to work for mapped catalogs. */ if (IsSystemRelation(OldHeap)) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot rewrite system relation \"%s\"", RelationGetRelationName(OldHeap)))); if (RelationIsUsedAsCatalogTable(OldHeap)) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot rewrite table \"%s\" used as a catalog table", RelationGetRelationName(OldHeap)))); /* * Don't allow rewrite on temp tables of other backends ... their * local buffer manager is not going to cope. (This is redundant * with the check in CheckAlterTableIsSafe, but for safety we'll * check here too.) */ if (RELATION_IS_OTHER_TEMP(OldHeap)) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot rewrite temporary tables of other sessions"))); /* * Select destination tablespace (same as original unless user * requested a change) */ if (tab->newTableSpace) NewTableSpace = tab->newTableSpace; else NewTableSpace = OldHeap->rd_rel->reltablespace; /* * Select destination access method (same as original unless user * requested a change) */ if (tab->chgAccessMethod) NewAccessMethod = tab->newAccessMethod; else NewAccessMethod = OldHeap->rd_rel->relam; /* * Select persistence of transient table (same as original unless * user requested a change) */ persistence = tab->chgPersistence ? tab->newrelpersistence : OldHeap->rd_rel->relpersistence; table_close(OldHeap, NoLock); /* * Fire off an Event Trigger now, before actually rewriting the * table. * * We don't support Event Trigger for nested commands anywhere, * here included, and parsetree is given NULL when coming from * AlterTableInternal. * * And fire it only once. */ if (parsetree) EventTriggerTableRewrite((Node *) parsetree, tab->relid, tab->rewrite); /* * Create transient table that will receive the modified data. * * Ensure it is marked correctly as logged or unlogged. We have * to do this here so that buffers for the new relfilenumber will * have the right persistence set, and at the same time ensure * that the original filenumbers's buffers will get read in with * the correct setting (i.e. the original one). Otherwise a * rollback after the rewrite would possibly result with buffers * for the original filenumbers having the wrong persistence * setting. * * NB: This relies on swap_relation_files() also swapping the * persistence. That wouldn't work for pg_class, but that can't be * unlogged anyway. */ OIDNewHeap = make_new_heap(tab->relid, NewTableSpace, NewAccessMethod, persistence, lockmode); /* * Copy the heap data into the new table with the desired * modifications, and test the current data within the table * against new constraints generated by ALTER TABLE commands. */ ATRewriteTable(tab, OIDNewHeap); /* * Swap the physical files of the old and new heaps, then rebuild * indexes and discard the old heap. We can use RecentXmin for * the table's new relfrozenxid because we rewrote all the tuples * in ATRewriteTable, so no older Xid remains in the table. Also, * we never try to swap toast tables by content, since we have no * interest in letting this code work on system catalogs. */ finish_heap_swap(tab->relid, OIDNewHeap, false, false, true, !OidIsValid(tab->newTableSpace), true, /* reindex */ RecentXmin, ReadNextMultiXactId(), persistence); InvokeObjectPostAlterHook(RelationRelationId, tab->relid, 0); } else if (tab->rewrite > 0 && tab->relkind == RELKIND_SEQUENCE) { if (tab->chgPersistence) SequenceChangePersistence(tab->relid, tab->newrelpersistence); } else { /* * If required, test the current data within the table against new * constraints generated by ALTER TABLE commands, but don't * rebuild data. */ if (tab->constraints != NIL || tab->verify_new_notnull || tab->partition_constraint != NULL) ATRewriteTable(tab, InvalidOid); /* * If we had SET TABLESPACE but no reason to reconstruct tuples, * just do a block-by-block copy. */ if (tab->newTableSpace) ATExecSetTableSpace(tab->relid, tab->newTableSpace, lockmode); } /* * Also change persistence of owned sequences, so that it matches the * table persistence. */ if (tab->chgPersistence) { List *seqlist = getOwnedSequences(tab->relid); ListCell *lc; foreach(lc, seqlist) { Oid seq_relid = lfirst_oid(lc); SequenceChangePersistence(seq_relid, tab->newrelpersistence); } } } /* * Foreign key constraints are checked in a final pass, since (a) it's * generally best to examine each one separately, and (b) it's at least * theoretically possible that we have changed both relations of the * foreign key, and we'd better have finished both rewrites before we try * to read the tables. */ foreach(ltab, *wqueue) { AlteredTableInfo *tab = (AlteredTableInfo *) lfirst(ltab); Relation rel = NULL; ListCell *lcon; /* Relations without storage may be ignored here too */ if (!RELKIND_HAS_STORAGE(tab->relkind)) continue; foreach(lcon, tab->constraints) { NewConstraint *con = lfirst(lcon); if (con->contype == CONSTR_FOREIGN) { Constraint *fkconstraint = (Constraint *) con->qual; Relation refrel; if (rel == NULL) { /* Long since locked, no need for another */ rel = table_open(tab->relid, NoLock); } refrel = table_open(con->refrelid, RowShareLock); validateForeignKeyConstraint(fkconstraint->conname, rel, refrel, con->refindid, con->conid, con->conwithperiod); /* * No need to mark the constraint row as validated, we did * that when we inserted the row earlier. */ table_close(refrel, NoLock); } } if (rel) table_close(rel, NoLock); } /* Finally, run any afterStmts that were queued up */ foreach(ltab, *wqueue) { AlteredTableInfo *tab = (AlteredTableInfo *) lfirst(ltab); ListCell *lc; foreach(lc, tab->afterStmts) { Node *stmt = (Node *) lfirst(lc); ProcessUtilityForAlterTable(stmt, context); CommandCounterIncrement(); } } } /* * ATRewriteTable: scan or rewrite one table * * A rewrite is requested by passing a valid OIDNewHeap; in that case, caller * must already hold AccessExclusiveLock on it. */ static void ATRewriteTable(AlteredTableInfo *tab, Oid OIDNewHeap) { Relation oldrel; Relation newrel; TupleDesc oldTupDesc; TupleDesc newTupDesc; bool needscan = false; List *notnull_attrs; List *notnull_virtual_attrs; int i; ListCell *l; EState *estate; CommandId mycid; BulkInsertState bistate; uint32 ti_options; ExprState *partqualstate = NULL; /* * Open the relation(s). We have surely already locked the existing * table. */ oldrel = table_open(tab->relid, NoLock); oldTupDesc = tab->oldDesc; newTupDesc = RelationGetDescr(oldrel); /* includes all mods */ if (OidIsValid(OIDNewHeap)) { Assert(CheckRelationOidLockedByMe(OIDNewHeap, AccessExclusiveLock, false)); newrel = table_open(OIDNewHeap, NoLock); } else newrel = NULL; /* * Prepare a BulkInsertState and options for table_tuple_insert. The FSM * is empty, so don't bother using it. */ if (newrel) { mycid = GetCurrentCommandId(true); bistate = GetBulkInsertState(); ti_options = TABLE_INSERT_SKIP_FSM; } else { /* keep compiler quiet about using these uninitialized */ mycid = 0; bistate = NULL; ti_options = 0; } /* * Generate the constraint and default execution states */ estate = CreateExecutorState(); /* Build the needed expression execution states */ foreach(l, tab->constraints) { NewConstraint *con = lfirst(l); switch (con->contype) { case CONSTR_CHECK: needscan = true; con->qualstate = ExecPrepareExpr((Expr *) expand_generated_columns_in_expr(con->qual, oldrel, 1), estate); break; case CONSTR_FOREIGN: /* Nothing to do here */ break; default: elog(ERROR, "unrecognized constraint type: %d", (int) con->contype); } } /* Build expression execution states for partition check quals */ if (tab->partition_constraint) { needscan = true; partqualstate = ExecPrepareExpr(tab->partition_constraint, estate); } foreach(l, tab->newvals) { NewColumnValue *ex = lfirst(l); /* expr already planned */ ex->exprstate = ExecInitExpr(ex->expr, NULL); } notnull_attrs = notnull_virtual_attrs = NIL; if (newrel || tab->verify_new_notnull) { /* * If we are rebuilding the tuples OR if we added any new but not * verified not-null constraints, check all *valid* not-null * constraints. This is a bit of overkill but it minimizes risk of * bugs. * * notnull_attrs does *not* collect attribute numbers for valid * not-null constraints over virtual generated columns; instead, they * are collected in notnull_virtual_attrs for verification elsewhere. */ for (i = 0; i < newTupDesc->natts; i++) { CompactAttribute *attr = TupleDescCompactAttr(newTupDesc, i); if (attr->attnullability == ATTNULLABLE_VALID && !attr->attisdropped) { Form_pg_attribute wholeatt = TupleDescAttr(newTupDesc, i); if (wholeatt->attgenerated != ATTRIBUTE_GENERATED_VIRTUAL) notnull_attrs = lappend_int(notnull_attrs, wholeatt->attnum); else notnull_virtual_attrs = lappend_int(notnull_virtual_attrs, wholeatt->attnum); } } if (notnull_attrs || notnull_virtual_attrs) needscan = true; } if (newrel || needscan) { ExprContext *econtext; TupleTableSlot *oldslot; TupleTableSlot *newslot; TableScanDesc scan; MemoryContext oldCxt; List *dropped_attrs = NIL; ListCell *lc; Snapshot snapshot; ResultRelInfo *rInfo = NULL; /* * When adding or changing a virtual generated column with a not-null * constraint, we need to evaluate whether the generation expression * is null. For that, we borrow ExecRelGenVirtualNotNull(). Here, we * prepare a dummy ResultRelInfo. */ if (notnull_virtual_attrs != NIL) { MemoryContext oldcontext; Assert(newTupDesc->constr->has_generated_virtual); Assert(newTupDesc->constr->has_not_null); oldcontext = MemoryContextSwitchTo(estate->es_query_cxt); rInfo = makeNode(ResultRelInfo); InitResultRelInfo(rInfo, oldrel, 0, /* dummy rangetable index */ NULL, estate->es_instrument); MemoryContextSwitchTo(oldcontext); } if (newrel) ereport(DEBUG1, (errmsg_internal("rewriting table \"%s\"", RelationGetRelationName(oldrel)))); else ereport(DEBUG1, (errmsg_internal("verifying table \"%s\"", RelationGetRelationName(oldrel)))); if (newrel) { /* * All predicate locks on the tuples or pages are about to be made * invalid, because we move tuples around. Promote them to * relation locks. */ TransferPredicateLocksToHeapRelation(oldrel); } econtext = GetPerTupleExprContext(estate); /* * Create necessary tuple slots. When rewriting, two slots are needed, * otherwise one suffices. In the case where one slot suffices, we * need to use the new tuple descriptor, otherwise some constraints * can't be evaluated. Note that even when the tuple layout is the * same and no rewrite is required, the tupDescs might not be * (consider ADD COLUMN without a default). */ if (tab->rewrite) { Assert(newrel != NULL); oldslot = MakeSingleTupleTableSlot(oldTupDesc, table_slot_callbacks(oldrel)); newslot = MakeSingleTupleTableSlot(newTupDesc, table_slot_callbacks(newrel)); /* * Set all columns in the new slot to NULL initially, to ensure * columns added as part of the rewrite are initialized to NULL. * That is necessary as tab->newvals will not contain an * expression for columns with a NULL default, e.g. when adding a * column without a default together with a column with a default * requiring an actual rewrite. */ ExecStoreAllNullTuple(newslot); } else { oldslot = MakeSingleTupleTableSlot(newTupDesc, table_slot_callbacks(oldrel)); newslot = NULL; } /* * Any attributes that are dropped according to the new tuple * descriptor can be set to NULL. We precompute the list of dropped * attributes to avoid needing to do so in the per-tuple loop. */ for (i = 0; i < newTupDesc->natts; i++) { if (TupleDescAttr(newTupDesc, i)->attisdropped) dropped_attrs = lappend_int(dropped_attrs, i); } /* * Scan through the rows, generating a new row if needed and then * checking all the constraints. */ snapshot = RegisterSnapshot(GetLatestSnapshot()); scan = table_beginscan(oldrel, snapshot, 0, NULL, SO_NONE); /* * Switch to per-tuple memory context and reset it for each tuple * produced, so we don't leak memory. */ oldCxt = MemoryContextSwitchTo(GetPerTupleMemoryContext(estate)); while (table_scan_getnextslot(scan, ForwardScanDirection, oldslot)) { TupleTableSlot *insertslot; if (tab->rewrite > 0) { /* Extract data from old tuple */ slot_getallattrs(oldslot); ExecClearTuple(newslot); /* copy attributes */ memcpy(newslot->tts_values, oldslot->tts_values, sizeof(Datum) * oldslot->tts_nvalid); memcpy(newslot->tts_isnull, oldslot->tts_isnull, sizeof(bool) * oldslot->tts_nvalid); /* Set dropped attributes to null in new tuple */ foreach(lc, dropped_attrs) newslot->tts_isnull[lfirst_int(lc)] = true; /* * Constraints and GENERATED expressions might reference the * tableoid column, so fill tts_tableOid with the desired * value. (We must do this each time, because it gets * overwritten with newrel's OID during storing.) */ newslot->tts_tableOid = RelationGetRelid(oldrel); /* * Process supplied expressions to replace selected columns. * * First, evaluate expressions whose inputs come from the old * tuple. */ econtext->ecxt_scantuple = oldslot; foreach(l, tab->newvals) { NewColumnValue *ex = lfirst(l); if (ex->is_generated) continue; newslot->tts_values[ex->attnum - 1] = ExecEvalExpr(ex->exprstate, econtext, &newslot->tts_isnull[ex->attnum - 1]); } ExecStoreVirtualTuple(newslot); /* * Now, evaluate any expressions whose inputs come from the * new tuple. We assume these columns won't reference each * other, so that there's no ordering dependency. */ econtext->ecxt_scantuple = newslot; foreach(l, tab->newvals) { NewColumnValue *ex = lfirst(l); if (!ex->is_generated) continue; newslot->tts_values[ex->attnum - 1] = ExecEvalExpr(ex->exprstate, econtext, &newslot->tts_isnull[ex->attnum - 1]); } insertslot = newslot; } else { /* * If there's no rewrite, old and new table are guaranteed to * have the same AM, so we can just use the old slot to verify * new constraints etc. */ insertslot = oldslot; } /* Now check any constraints on the possibly-changed tuple */ econtext->ecxt_scantuple = insertslot; foreach_int(attn, notnull_attrs) { if (slot_attisnull(insertslot, attn)) { Form_pg_attribute attr = TupleDescAttr(newTupDesc, attn - 1); ereport(ERROR, (errcode(ERRCODE_NOT_NULL_VIOLATION), errmsg("column \"%s\" of relation \"%s\" contains null values", NameStr(attr->attname), RelationGetRelationName(oldrel)), errtablecol(oldrel, attn))); } } if (notnull_virtual_attrs != NIL) { AttrNumber attnum; attnum = ExecRelGenVirtualNotNull(rInfo, insertslot, estate, notnull_virtual_attrs); if (attnum != InvalidAttrNumber) { Form_pg_attribute attr = TupleDescAttr(newTupDesc, attnum - 1); ereport(ERROR, errcode(ERRCODE_NOT_NULL_VIOLATION), errmsg("column \"%s\" of relation \"%s\" contains null values", NameStr(attr->attname), RelationGetRelationName(oldrel)), errtablecol(oldrel, attnum)); } } foreach(l, tab->constraints) { NewConstraint *con = lfirst(l); switch (con->contype) { case CONSTR_CHECK: if (!ExecCheck(con->qualstate, econtext)) ereport(ERROR, (errcode(ERRCODE_CHECK_VIOLATION), errmsg("check constraint \"%s\" of relation \"%s\" is violated by some row", con->name, RelationGetRelationName(oldrel)), errtableconstraint(oldrel, con->name))); break; case CONSTR_NOTNULL: case CONSTR_FOREIGN: /* Nothing to do here */ break; default: elog(ERROR, "unrecognized constraint type: %d", (int) con->contype); } } if (partqualstate && !ExecCheck(partqualstate, econtext)) { if (tab->validate_default) ereport(ERROR, (errcode(ERRCODE_CHECK_VIOLATION), errmsg("updated partition constraint for default partition \"%s\" would be violated by some row", RelationGetRelationName(oldrel)), errtable(oldrel))); else ereport(ERROR, (errcode(ERRCODE_CHECK_VIOLATION), errmsg("partition constraint of relation \"%s\" is violated by some row", RelationGetRelationName(oldrel)), errtable(oldrel))); } /* Write the tuple out to the new relation */ if (newrel) table_tuple_insert(newrel, insertslot, mycid, ti_options, bistate); ResetExprContext(econtext); CHECK_FOR_INTERRUPTS(); } MemoryContextSwitchTo(oldCxt); table_endscan(scan); UnregisterSnapshot(snapshot); ExecDropSingleTupleTableSlot(oldslot); if (newslot) ExecDropSingleTupleTableSlot(newslot); } FreeExecutorState(estate); table_close(oldrel, NoLock); if (newrel) { FreeBulkInsertState(bistate); table_finish_bulk_insert(newrel, ti_options); table_close(newrel, NoLock); } } /* * ATGetQueueEntry: find or create an entry in the ALTER TABLE work queue */ static AlteredTableInfo * ATGetQueueEntry(List **wqueue, Relation rel) { Oid relid = RelationGetRelid(rel); AlteredTableInfo *tab; ListCell *ltab; foreach(ltab, *wqueue) { tab = (AlteredTableInfo *) lfirst(ltab); if (tab->relid == relid) return tab; } /* * Not there, so add it. Note that we make a copy of the relation's * existing descriptor before anything interesting can happen to it. */ tab = palloc0_object(AlteredTableInfo); tab->relid = relid; tab->rel = NULL; /* set later */ tab->relkind = rel->rd_rel->relkind; tab->oldDesc = CreateTupleDescCopyConstr(RelationGetDescr(rel)); tab->newAccessMethod = InvalidOid; tab->chgAccessMethod = false; tab->newTableSpace = InvalidOid; tab->newrelpersistence = RELPERSISTENCE_PERMANENT; tab->chgPersistence = false; *wqueue = lappend(*wqueue, tab); return tab; } static const char * alter_table_type_to_string(AlterTableType cmdtype) { switch (cmdtype) { case AT_AddColumn: case AT_AddColumnToView: return "ADD COLUMN"; case AT_ColumnDefault: case AT_CookedColumnDefault: return "ALTER COLUMN ... SET DEFAULT"; case AT_DropNotNull: return "ALTER COLUMN ... DROP NOT NULL"; case AT_SetNotNull: return "ALTER COLUMN ... SET NOT NULL"; case AT_SetExpression: return "ALTER COLUMN ... SET EXPRESSION"; case AT_DropExpression: return "ALTER COLUMN ... DROP EXPRESSION"; case AT_SetStatistics: return "ALTER COLUMN ... SET STATISTICS"; case AT_SetOptions: return "ALTER COLUMN ... SET"; case AT_ResetOptions: return "ALTER COLUMN ... RESET"; case AT_SetStorage: return "ALTER COLUMN ... SET STORAGE"; case AT_SetCompression: return "ALTER COLUMN ... SET COMPRESSION"; case AT_DropColumn: return "DROP COLUMN"; case AT_AddIndex: case AT_ReAddIndex: return NULL; /* not real grammar */ case AT_AddConstraint: case AT_ReAddConstraint: case AT_ReAddDomainConstraint: case AT_AddIndexConstraint: return "ADD CONSTRAINT"; case AT_AlterConstraint: return "ALTER CONSTRAINT"; case AT_ValidateConstraint: return "VALIDATE CONSTRAINT"; case AT_DropConstraint: return "DROP CONSTRAINT"; case AT_ReAddComment: return NULL; /* not real grammar */ case AT_AlterColumnType: return "ALTER COLUMN ... SET DATA TYPE"; case AT_AlterColumnGenericOptions: return "ALTER COLUMN ... OPTIONS"; case AT_ChangeOwner: return "OWNER TO"; case AT_ClusterOn: return "CLUSTER ON"; case AT_DropCluster: return "SET WITHOUT CLUSTER"; case AT_SetAccessMethod: return "SET ACCESS METHOD"; case AT_SetLogged: return "SET LOGGED"; case AT_SetUnLogged: return "SET UNLOGGED"; case AT_DropOids: return "SET WITHOUT OIDS"; case AT_SetTableSpace: return "SET TABLESPACE"; case AT_SetRelOptions: return "SET"; case AT_ResetRelOptions: return "RESET"; case AT_ReplaceRelOptions: return NULL; /* not real grammar */ case AT_EnableTrig: return "ENABLE TRIGGER"; case AT_EnableAlwaysTrig: return "ENABLE ALWAYS TRIGGER"; case AT_EnableReplicaTrig: return "ENABLE REPLICA TRIGGER"; case AT_DisableTrig: return "DISABLE TRIGGER"; case AT_EnableTrigAll: return "ENABLE TRIGGER ALL"; case AT_DisableTrigAll: return "DISABLE TRIGGER ALL"; case AT_EnableTrigUser: return "ENABLE TRIGGER USER"; case AT_DisableTrigUser: return "DISABLE TRIGGER USER"; case AT_EnableRule: return "ENABLE RULE"; case AT_EnableAlwaysRule: return "ENABLE ALWAYS RULE"; case AT_EnableReplicaRule: return "ENABLE REPLICA RULE"; case AT_DisableRule: return "DISABLE RULE"; case AT_AddInherit: return "INHERIT"; case AT_DropInherit: return "NO INHERIT"; case AT_AddOf: return "OF"; case AT_DropOf: return "NOT OF"; case AT_ReplicaIdentity: return "REPLICA IDENTITY"; case AT_EnableRowSecurity: return "ENABLE ROW SECURITY"; case AT_DisableRowSecurity: return "DISABLE ROW SECURITY"; case AT_ForceRowSecurity: return "FORCE ROW SECURITY"; case AT_NoForceRowSecurity: return "NO FORCE ROW SECURITY"; case AT_GenericOptions: return "OPTIONS"; case AT_AttachPartition: return "ATTACH PARTITION"; case AT_DetachPartition: return "DETACH PARTITION"; case AT_DetachPartitionFinalize: return "DETACH PARTITION ... FINALIZE"; case AT_MergePartitions: return "MERGE PARTITIONS"; case AT_SplitPartition: return "SPLIT PARTITION"; case AT_AddIdentity: return "ALTER COLUMN ... ADD IDENTITY"; case AT_SetIdentity: return "ALTER COLUMN ... SET"; case AT_DropIdentity: return "ALTER COLUMN ... DROP IDENTITY"; case AT_ReAddStatistics: return NULL; /* not real grammar */ } return NULL; } /* * ATSimplePermissions * * - Ensure that it is a relation (or possibly a view) * - Ensure this user is the owner * - Ensure that it is not a system table */ static void ATSimplePermissions(AlterTableType cmdtype, Relation rel, int allowed_targets) { int actual_target; switch (rel->rd_rel->relkind) { case RELKIND_RELATION: actual_target = ATT_TABLE; break; case RELKIND_PARTITIONED_TABLE: actual_target = ATT_PARTITIONED_TABLE; break; case RELKIND_VIEW: actual_target = ATT_VIEW; break; case RELKIND_MATVIEW: actual_target = ATT_MATVIEW; break; case RELKIND_INDEX: actual_target = ATT_INDEX; break; case RELKIND_PARTITIONED_INDEX: actual_target = ATT_PARTITIONED_INDEX; break; case RELKIND_COMPOSITE_TYPE: actual_target = ATT_COMPOSITE_TYPE; break; case RELKIND_FOREIGN_TABLE: actual_target = ATT_FOREIGN_TABLE; break; case RELKIND_SEQUENCE: actual_target = ATT_SEQUENCE; break; default: actual_target = 0; break; } /* Wrong target type? */ if ((actual_target & allowed_targets) == 0) { const char *action_str = alter_table_type_to_string(cmdtype); if (action_str) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), /* translator: %s is a group of some SQL keywords */ errmsg("ALTER action %s cannot be performed on relation \"%s\"", action_str, RelationGetRelationName(rel)), errdetail_relkind_not_supported(rel->rd_rel->relkind))); else /* internal error? */ elog(ERROR, "invalid ALTER action attempted on relation \"%s\"", RelationGetRelationName(rel)); } /* Permissions checks */ if (!object_ownercheck(RelationRelationId, RelationGetRelid(rel), GetUserId())) aclcheck_error(ACLCHECK_NOT_OWNER, get_relkind_objtype(rel->rd_rel->relkind), RelationGetRelationName(rel)); /* * Conflict log tables are used internally for logical replication * conflict logging and should not be altered directly, as it could * disrupt conflict logging. Direct ALTER commands are already rejected * during relation lookup in RangeVarCallbackForAlterRelation(), and * AlterTableMoveAll() skips these tables, so a conflict log table does * not normally reach here; this check guards any internal caller that * arrives via AlterTableInternal(). */ if (IsConflictLogTableClass(rel->rd_rel)) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot alter conflict log table \"%s\"", RelationGetRelationName(rel)), errdetail("Conflict log tables are system-managed tables for logical replication conflicts."))); if (!allowSystemTableMods && IsSystemRelation(rel)) ereport(ERROR, (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), errmsg("permission denied: \"%s\" is a system catalog", RelationGetRelationName(rel)))); } /* * ATSimpleRecursion * * Simple table recursion sufficient for most ALTER TABLE operations. * All direct and indirect children are processed in an unspecified order. * Note that if a child inherits from the original table via multiple * inheritance paths, it will be visited just once. */ static void ATSimpleRecursion(List **wqueue, Relation rel, AlterTableCmd *cmd, bool recurse, LOCKMODE lockmode, AlterTableUtilityContext *context) { /* * Propagate to children, if desired and if there are (or might be) any * children. */ if (recurse && rel->rd_rel->relhassubclass) { Oid relid = RelationGetRelid(rel); ListCell *child; List *children; children = find_all_inheritors(relid, lockmode, NULL); /* * find_all_inheritors does the recursive search of the inheritance * hierarchy, so all we have to do is process all of the relids in the * list that it returns. */ foreach(child, children) { Oid childrelid = lfirst_oid(child); Relation childrel; if (childrelid == relid) continue; /* find_all_inheritors already got lock */ childrel = relation_open(childrelid, NoLock); CheckAlterTableIsSafe(childrel); ATPrepCmd(wqueue, childrel, cmd, false, true, lockmode, context); relation_close(childrel, NoLock); } } } /* * Obtain list of partitions of the given table, locking them all at the given * lockmode and ensuring that they all pass CheckAlterTableIsSafe. * * This function is a no-op if the given relation is not a partitioned table; * in particular, nothing is done if it's a legacy inheritance parent. */ static void ATCheckPartitionsNotInUse(Relation rel, LOCKMODE lockmode) { if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) { List *inh; ListCell *cell; inh = find_all_inheritors(RelationGetRelid(rel), lockmode, NULL); /* first element is the parent rel; must ignore it */ for_each_from(cell, inh, 1) { Relation childrel; /* find_all_inheritors already got lock */ childrel = table_open(lfirst_oid(cell), NoLock); CheckAlterTableIsSafe(childrel); table_close(childrel, NoLock); } list_free(inh); } } /* * ATTypedTableRecursion * * Propagate ALTER TYPE operations to the typed tables of that type. * Also check the RESTRICT/CASCADE behavior. Given CASCADE, also permit * recursion to inheritance children of the typed tables. */ static void ATTypedTableRecursion(List **wqueue, Relation rel, AlterTableCmd *cmd, LOCKMODE lockmode, AlterTableUtilityContext *context) { ListCell *child; List *children; Assert(rel->rd_rel->relkind == RELKIND_COMPOSITE_TYPE); children = find_typed_table_dependencies(rel->rd_rel->reltype, RelationGetRelationName(rel), cmd->behavior); foreach(child, children) { Oid childrelid = lfirst_oid(child); Relation childrel; childrel = relation_open(childrelid, lockmode); CheckAlterTableIsSafe(childrel); ATPrepCmd(wqueue, childrel, cmd, true, true, lockmode, context); relation_close(childrel, NoLock); } } /* * find_composite_type_dependencies * * Check to see if the type "typeOid" is being used as a column in some table * (possibly nested several levels deep in composite types, arrays, etc!). * Eventually, we'd like to propagate the check or rewrite operation * into such tables, but for now, just error out if we find any. * * Caller should provide either the associated relation of a rowtype, * or a type name (not both) for use in the error message, if any. * * Note that "typeOid" is not necessarily a composite type; it could also be * another container type such as an array or range, or a domain over one of * these things. The name of this function is therefore somewhat historical, * but it's not worth changing. * * We assume that functions and views depending on the type are not reasons * to reject the ALTER. (How safe is this really?) */ void find_composite_type_dependencies(Oid typeOid, Relation origRelation, const char *origTypeName) { Relation depRel; ScanKeyData key[2]; SysScanDesc depScan; HeapTuple depTup; /* since this function recurses, it could be driven to stack overflow */ check_stack_depth(); /* * We scan pg_depend to find those things that depend on the given type. * (We assume we can ignore refobjsubid for a type.) */ depRel = table_open(DependRelationId, AccessShareLock); ScanKeyInit(&key[0], Anum_pg_depend_refclassid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(TypeRelationId)); ScanKeyInit(&key[1], Anum_pg_depend_refobjid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(typeOid)); depScan = systable_beginscan(depRel, DependReferenceIndexId, true, NULL, 2, key); while (HeapTupleIsValid(depTup = systable_getnext(depScan))) { Form_pg_depend pg_depend = (Form_pg_depend) GETSTRUCT(depTup); Relation rel; TupleDesc tupleDesc; Form_pg_attribute att; /* Check for directly dependent types */ if (pg_depend->classid == TypeRelationId) { /* * This must be an array, domain, or range containing the given * type, so recursively check for uses of this type. Note that * any error message will mention the original type not the * container; this is intentional. */ find_composite_type_dependencies(pg_depend->objid, origRelation, origTypeName); continue; } /* Else, ignore dependees that aren't relations */ if (pg_depend->classid != RelationRelationId) continue; rel = relation_open(pg_depend->objid, AccessShareLock); tupleDesc = RelationGetDescr(rel); /* * If objsubid identifies a specific column, refer to that in error * messages. Otherwise, search to see if there's a user column of the * type. (We assume system columns are never of interesting types.) * The search is needed because an index containing an expression * column of the target type will just be recorded as a whole-relation * dependency. If we do not find a column of the type, the dependency * must indicate that the type is transiently referenced in an index * expression but not stored on disk, which we assume is OK, just as * we do for references in views. (It could also be that the target * type is embedded in some container type that is stored in an index * column, but the previous recursion should catch such cases.) */ if (pg_depend->objsubid > 0 && pg_depend->objsubid <= tupleDesc->natts) att = TupleDescAttr(tupleDesc, pg_depend->objsubid - 1); else { att = NULL; for (int attno = 1; attno <= tupleDesc->natts; attno++) { att = TupleDescAttr(tupleDesc, attno - 1); if (att->atttypid == typeOid && !att->attisdropped) break; att = NULL; } if (att == NULL) { /* No such column, so assume OK */ relation_close(rel, AccessShareLock); continue; } } /* * We definitely should reject if the relation has storage. If it's * partitioned, then perhaps we don't have to reject: if there are * partitions then we'll fail when we find one, else there is no * stored data to worry about. However, it's possible that the type * change would affect conclusions about whether the type is sortable * or hashable and thus (if it's a partitioning column) break the * partitioning rule. For now, reject for partitioned rels too. */ if (RELKIND_HAS_STORAGE(rel->rd_rel->relkind) || RELKIND_HAS_PARTITIONS(rel->rd_rel->relkind)) { if (origTypeName) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter type \"%s\" because column \"%s.%s\" uses it", origTypeName, RelationGetRelationName(rel), NameStr(att->attname)))); else if (origRelation->rd_rel->relkind == RELKIND_COMPOSITE_TYPE) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter type \"%s\" because column \"%s.%s\" uses it", RelationGetRelationName(origRelation), RelationGetRelationName(rel), NameStr(att->attname)))); else if (origRelation->rd_rel->relkind == RELKIND_FOREIGN_TABLE) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter foreign table \"%s\" because column \"%s.%s\" uses its row type", RelationGetRelationName(origRelation), RelationGetRelationName(rel), NameStr(att->attname)))); else ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter table \"%s\" because column \"%s.%s\" uses its row type", RelationGetRelationName(origRelation), RelationGetRelationName(rel), NameStr(att->attname)))); } else if (OidIsValid(rel->rd_rel->reltype)) { /* * A view or composite type itself isn't a problem, but we must * recursively check for indirect dependencies via its rowtype. */ find_composite_type_dependencies(rel->rd_rel->reltype, origRelation, origTypeName); } relation_close(rel, AccessShareLock); } systable_endscan(depScan); relation_close(depRel, AccessShareLock); } /* * find_typed_table_dependencies * * Check to see if a composite type is being used as the type of a * typed table. Abort if any are found and behavior is RESTRICT. * Else return the list of tables. */ static List * find_typed_table_dependencies(Oid typeOid, const char *typeName, DropBehavior behavior) { Relation classRel; ScanKeyData key[1]; TableScanDesc scan; HeapTuple tuple; List *result = NIL; classRel = table_open(RelationRelationId, AccessShareLock); ScanKeyInit(&key[0], Anum_pg_class_reloftype, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(typeOid)); scan = table_beginscan_catalog(classRel, 1, key); while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL) { Form_pg_class classform = (Form_pg_class) GETSTRUCT(tuple); if (behavior == DROP_RESTRICT) ereport(ERROR, (errcode(ERRCODE_DEPENDENT_OBJECTS_STILL_EXIST), errmsg("cannot alter type \"%s\" because it is the type of a typed table", typeName), errhint("Use ALTER ... CASCADE to alter the typed tables too."))); else result = lappend_oid(result, classform->oid); } table_endscan(scan); table_close(classRel, AccessShareLock); return result; } /* * check_of_type * * Check whether a type is suitable for CREATE TABLE OF/ALTER TABLE OF. If it * isn't suitable, throw an error. Currently, we require that the type * originated with CREATE TYPE AS. We could support any row type, but doing so * would require handling a number of extra corner cases in the DDL commands. * (Also, allowing domain-over-composite would open up a can of worms about * whether and how the domain's constraints should apply to derived tables.) */ void check_of_type(HeapTuple typetuple) { Form_pg_type typ = (Form_pg_type) GETSTRUCT(typetuple); bool typeOk = false; if (typ->typtype == TYPTYPE_COMPOSITE) { Relation typeRelation; Assert(OidIsValid(typ->typrelid)); typeRelation = relation_open(typ->typrelid, AccessShareLock); typeOk = (typeRelation->rd_rel->relkind == RELKIND_COMPOSITE_TYPE); /* * Close the parent rel, but keep our AccessShareLock on it until xact * commit. That will prevent someone else from deleting or ALTERing * the type before the typed table creation/conversion commits. */ relation_close(typeRelation, NoLock); if (!typeOk) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("type %s is the row type of another table", format_type_be(typ->oid)), errdetail("A typed table must use a stand-alone composite type created with CREATE TYPE."))); } else ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("type %s is not a composite type", format_type_be(typ->oid)))); } /* * ALTER TABLE ADD COLUMN * * Adds an additional attribute to a relation making the assumption that * CHECK, NOT NULL, and FOREIGN KEY constraints will be removed from the * AT_AddColumn AlterTableCmd by parse_utilcmd.c and added as independent * AlterTableCmd's. * * ADD COLUMN cannot use the normal ALTER TABLE recursion mechanism, because we * have to decide at runtime whether to recurse or not depending on whether we * actually add a column or merely merge with an existing column. (We can't * check this in a static pre-pass because it won't handle multiple inheritance * situations correctly.) */ static void ATPrepAddColumn(List **wqueue, Relation rel, bool recurse, bool recursing, bool is_view, AlterTableCmd *cmd, LOCKMODE lockmode, AlterTableUtilityContext *context) { if (rel->rd_rel->reloftype && !recursing) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot add column to typed table"))); if (rel->rd_rel->relkind == RELKIND_COMPOSITE_TYPE) ATTypedTableRecursion(wqueue, rel, cmd, lockmode, context); if (recurse && !is_view) cmd->recurse = true; } /* * Add a column to a table. The return value is the address of the * new column in the parent relation. * * cmd is pass-by-ref so that we can replace it with the parse-transformed * copy (but that happens only after we check for IF NOT EXISTS). */ static ObjectAddress ATExecAddColumn(List **wqueue, AlteredTableInfo *tab, Relation rel, AlterTableCmd **cmd, bool recurse, bool recursing, LOCKMODE lockmode, AlterTablePass cur_pass, AlterTableUtilityContext *context) { Oid myrelid = RelationGetRelid(rel); ColumnDef *colDef = castNode(ColumnDef, (*cmd)->def); bool if_not_exists = (*cmd)->missing_ok; Relation pgclass, attrdesc; HeapTuple reltup; Form_pg_class relform; Form_pg_attribute attribute; int newattnum; char relkind; Expr *defval; List *children; ListCell *child; AlterTableCmd *childcmd; ObjectAddress address; TupleDesc tupdesc; /* since this function recurses, it could be driven to stack overflow */ check_stack_depth(); /* At top level, permission check was done in ATPrepCmd, else do it */ if (recursing) ATSimplePermissions((*cmd)->subtype, rel, ATT_TABLE | ATT_PARTITIONED_TABLE | ATT_FOREIGN_TABLE); if (rel->rd_rel->relispartition && !recursing) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot add column to a partition"))); attrdesc = table_open(AttributeRelationId, RowExclusiveLock); /* * Are we adding the column to a recursion child? If so, check whether to * merge with an existing definition for the column. If we do merge, we * must not recurse. Children will already have the column, and recursing * into them would mess up attinhcount. */ if (colDef->inhcount > 0) { HeapTuple tuple; /* Does child already have a column by this name? */ tuple = SearchSysCacheCopyAttName(myrelid, colDef->colname); if (HeapTupleIsValid(tuple)) { Form_pg_attribute childatt = (Form_pg_attribute) GETSTRUCT(tuple); Oid ctypeId; int32 ctypmod; Oid ccollid; /* Child column must match on type, typmod, and collation */ typenameTypeIdAndMod(NULL, colDef->typeName, &ctypeId, &ctypmod); if (ctypeId != childatt->atttypid || ctypmod != childatt->atttypmod) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("child table \"%s\" has different type for column \"%s\"", RelationGetRelationName(rel), colDef->colname))); ccollid = GetColumnDefCollation(NULL, colDef, ctypeId); if (ccollid != childatt->attcollation) ereport(ERROR, (errcode(ERRCODE_COLLATION_MISMATCH), errmsg("child table \"%s\" has different collation for column \"%s\"", RelationGetRelationName(rel), colDef->colname), errdetail("\"%s\" versus \"%s\"", get_collation_name(ccollid), get_collation_name(childatt->attcollation)))); /* Bump the existing child att's inhcount */ if (pg_add_s16_overflow(childatt->attinhcount, 1, &childatt->attinhcount)) ereport(ERROR, errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED), errmsg("too many inheritance parents")); CatalogTupleUpdate(attrdesc, &tuple->t_self, tuple); heap_freetuple(tuple); /* Inform the user about the merge */ ereport(NOTICE, (errmsg("merging definition of column \"%s\" for child \"%s\"", colDef->colname, RelationGetRelationName(rel)))); table_close(attrdesc, RowExclusiveLock); /* Make the child column change visible */ CommandCounterIncrement(); return InvalidObjectAddress; } } /* skip if the name already exists and if_not_exists is true */ if (!check_for_column_name_collision(rel, colDef->colname, if_not_exists)) { table_close(attrdesc, RowExclusiveLock); return InvalidObjectAddress; } /* * Okay, we need to add the column, so go ahead and do parse * transformation. This can result in queueing up, or even immediately * executing, subsidiary operations (such as creation of unique indexes); * so we mustn't do it until we have made the if_not_exists check. * * When recursing, the command was already transformed and we needn't do * so again. Also, if context isn't given we can't transform. (That * currently happens only for AT_AddColumnToView; we expect that view.c * passed us a ColumnDef that doesn't need work.) */ if (context != NULL && !recursing) { *cmd = ATParseTransformCmd(wqueue, tab, rel, *cmd, recurse, lockmode, cur_pass, context); Assert(*cmd != NULL); colDef = castNode(ColumnDef, (*cmd)->def); } /* * Regular inheritance children are independent enough not to inherit the * identity column from parent hence cannot recursively add identity * column if the table has inheritance children. * * Partitions, on the other hand, are integral part of a partitioned table * and inherit identity column. Hence propagate identity column down the * partition hierarchy. */ if (colDef->identity && recurse && rel->rd_rel->relkind != RELKIND_PARTITIONED_TABLE && find_inheritance_children(myrelid, NoLock) != NIL) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("cannot recursively add identity column to table that has child tables"))); pgclass = table_open(RelationRelationId, RowExclusiveLock); reltup = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(myrelid)); if (!HeapTupleIsValid(reltup)) elog(ERROR, "cache lookup failed for relation %u", myrelid); relform = (Form_pg_class) GETSTRUCT(reltup); relkind = relform->relkind; /* Determine the new attribute's number */ newattnum = relform->relnatts + 1; if (newattnum > MaxHeapAttributeNumber) ereport(ERROR, (errcode(ERRCODE_TOO_MANY_COLUMNS), errmsg("tables can have at most %d columns", MaxHeapAttributeNumber))); /* * Construct new attribute's pg_attribute entry. */ tupdesc = BuildDescForRelation(list_make1(colDef)); attribute = TupleDescAttr(tupdesc, 0); /* Fix up attribute number */ attribute->attnum = newattnum; /* make sure datatype is legal for a column */ CheckAttributeType(NameStr(attribute->attname), attribute->atttypid, attribute->attcollation, list_make1_oid(rel->rd_rel->reltype), (attribute->attgenerated == ATTRIBUTE_GENERATED_VIRTUAL ? CHKATYPE_IS_VIRTUAL : 0)); InsertPgAttributeTuples(attrdesc, tupdesc, myrelid, NULL, NULL); table_close(attrdesc, RowExclusiveLock); /* * Update pg_class tuple as appropriate */ relform->relnatts = newattnum; CatalogTupleUpdate(pgclass, &reltup->t_self, reltup); heap_freetuple(reltup); /* Post creation hook for new attribute */ InvokeObjectPostCreateHook(RelationRelationId, myrelid, newattnum); table_close(pgclass, RowExclusiveLock); /* Make the attribute's catalog entry visible */ CommandCounterIncrement(); /* * Store the DEFAULT, if any, in the catalogs */ if (colDef->raw_default) { RawColumnDefault *rawEnt; rawEnt = palloc_object(RawColumnDefault); rawEnt->attnum = attribute->attnum; rawEnt->raw_default = copyObject(colDef->raw_default); rawEnt->generated = colDef->generated; /* * This function is intended for CREATE TABLE, so it processes a * _list_ of defaults, but we just do one. */ AddRelationNewConstraints(rel, list_make1(rawEnt), NIL, false, true, false, NULL); /* Make the additional catalog changes visible */ CommandCounterIncrement(); } /* * Tell Phase 3 to fill in the default expression, if there is one. * * If there is no default, Phase 3 doesn't have to do anything, because * that effectively means that the default is NULL. The heap tuple access * routines always check for attnum > # of attributes in tuple, and return * NULL if so, so without any modification of the tuple data we will get * the effect of NULL values in the new column. * * An exception occurs when the new column is of a domain type: the domain * might have a not-null constraint, or a check constraint that indirectly * rejects nulls. If there are any domain constraints then we construct * an explicit NULL default value that will be passed through * CoerceToDomain processing. (This is a tad inefficient, since it causes * rewriting the table which we really wouldn't have to do; but we do it * to preserve the historical behavior that such a failure will be raised * only if the table currently contains some rows.) * * Note: we use build_column_default, and not just the cooked default * returned by AddRelationNewConstraints, so that the right thing happens * when a datatype's default applies. * * Note: it might seem that this should happen at the end of Phase 2, so * that the effects of subsequent subcommands can be taken into account. * It's intentional that we do it now, though. The new column should be * filled according to what is said in the ADD COLUMN subcommand, so that * the effects are the same as if this subcommand had been run by itself * and the later subcommands had been issued in new ALTER TABLE commands. * * We can skip this entirely for relations without storage, since Phase 3 * is certainly not going to touch them. */ if (RELKIND_HAS_STORAGE(relkind)) { bool has_domain_constraints; bool has_missing = false; /* * For an identity column, we can't use build_column_default(), * because the sequence ownership isn't set yet. So do it manually. */ if (colDef->identity) { NextValueExpr *nve = makeNode(NextValueExpr); nve->seqid = RangeVarGetRelid(colDef->identitySequence, NoLock, false); nve->typeId = attribute->atttypid; defval = (Expr *) nve; } else defval = (Expr *) build_column_default(rel, attribute->attnum); /* Build CoerceToDomain(NULL) expression if needed */ has_domain_constraints = DomainHasConstraints(attribute->atttypid, NULL); if (!defval && has_domain_constraints) { Oid baseTypeId; int32 baseTypeMod; Oid baseTypeColl; baseTypeMod = attribute->atttypmod; baseTypeId = getBaseTypeAndTypmod(attribute->atttypid, &baseTypeMod); baseTypeColl = get_typcollation(baseTypeId); defval = (Expr *) makeNullConst(baseTypeId, baseTypeMod, baseTypeColl); defval = (Expr *) coerce_to_target_type(NULL, (Node *) defval, baseTypeId, attribute->atttypid, attribute->atttypmod, COERCION_ASSIGNMENT, COERCE_IMPLICIT_CAST, -1); if (defval == NULL) /* should not happen */ elog(ERROR, "failed to coerce base type to domain"); } if (defval) { NewColumnValue *newval; /* Prepare defval for execution, either here or in Phase 3 */ defval = expression_planner(defval); /* Add the new default to the newvals list */ newval = palloc0_object(NewColumnValue); newval->attnum = attribute->attnum; newval->expr = defval; newval->is_generated = (colDef->generated != '\0'); tab->newvals = lappend(tab->newvals, newval); /* * Attempt to skip a complete table rewrite by storing the * specified DEFAULT value outside of the heap. This is only * allowed for plain relations and non-generated columns, and the * default expression can't be volatile (stable is OK). Note that * contain_volatile_functions deems CoerceToDomain immutable, but * here we consider that coercion to a domain with constraints is * volatile; else it might fail even when the table is empty. */ if (rel->rd_rel->relkind == RELKIND_RELATION && !colDef->generated && !has_domain_constraints && !contain_volatile_functions((Node *) defval)) { EState *estate; ExprState *exprState; Datum missingval; bool missingIsNull; /* Evaluate the default expression */ estate = CreateExecutorState(); exprState = ExecPrepareExpr(defval, estate); missingval = ExecEvalExpr(exprState, GetPerTupleExprContext(estate), &missingIsNull); /* If it turns out NULL, nothing to do; else store it */ if (!missingIsNull) { StoreAttrMissingVal(rel, attribute->attnum, missingval); /* Make the additional catalog change visible */ CommandCounterIncrement(); has_missing = true; } FreeExecutorState(estate); } else { /* * Failed to use missing mode. We have to do a table rewrite * to install the value --- unless it's a virtual generated * column. */ if (colDef->generated != ATTRIBUTE_GENERATED_VIRTUAL) tab->rewrite |= AT_REWRITE_DEFAULT_VAL; } } if (!has_missing) { /* * If the new column is NOT NULL, and there is no missing value, * tell Phase 3 it needs to check for NULLs. */ tab->verify_new_notnull |= colDef->is_not_null; } } /* * Add needed dependency entries for the new column. */ add_column_datatype_dependency(myrelid, newattnum, attribute->atttypid); add_column_collation_dependency(myrelid, newattnum, attribute->attcollation); /* * Propagate to children as appropriate. Unlike most other ALTER * routines, we have to do this one level of recursion at a time; we can't * use find_all_inheritors to do it in one pass. */ children = find_inheritance_children(RelationGetRelid(rel), lockmode); /* * If we are told not to recurse, there had better not be any child * tables; else the addition would put them out of step. */ if (children && !recurse) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("column must be added to child tables too"))); /* Children should see column as singly inherited */ if (!recursing) { childcmd = copyObject(*cmd); colDef = castNode(ColumnDef, childcmd->def); colDef->inhcount = 1; colDef->is_local = false; } else childcmd = *cmd; /* no need to copy again */ foreach(child, children) { Oid childrelid = lfirst_oid(child); Relation childrel; AlteredTableInfo *childtab; /* find_inheritance_children already got lock */ childrel = table_open(childrelid, NoLock); CheckAlterTableIsSafe(childrel); /* Find or create work queue entry for this table */ childtab = ATGetQueueEntry(wqueue, childrel); /* Recurse to child; return value is ignored */ ATExecAddColumn(wqueue, childtab, childrel, &childcmd, recurse, true, lockmode, cur_pass, context); table_close(childrel, NoLock); } ObjectAddressSubSet(address, RelationRelationId, myrelid, newattnum); return address; } /* * If a new or renamed column will collide with the name of an existing * column and if_not_exists is false then error out, else do nothing. */ static bool check_for_column_name_collision(Relation rel, const char *colname, bool if_not_exists) { HeapTuple attTuple; int attnum; /* * this test is deliberately not attisdropped-aware, since if one tries to * add a column matching a dropped column name, it's gonna fail anyway. */ attTuple = SearchSysCache2(ATTNAME, ObjectIdGetDatum(RelationGetRelid(rel)), PointerGetDatum(colname)); if (!HeapTupleIsValid(attTuple)) return true; attnum = ((Form_pg_attribute) GETSTRUCT(attTuple))->attnum; ReleaseSysCache(attTuple); /* * We throw a different error message for conflicts with system column * names, since they are normally not shown and the user might otherwise * be confused about the reason for the conflict. */ if (attnum <= 0) ereport(ERROR, (errcode(ERRCODE_DUPLICATE_COLUMN), errmsg("column name \"%s\" conflicts with a system column name", colname))); else { if (if_not_exists) { ereport(NOTICE, (errcode(ERRCODE_DUPLICATE_COLUMN), errmsg("column \"%s\" of relation \"%s\" already exists, skipping", colname, RelationGetRelationName(rel)))); return false; } ereport(ERROR, (errcode(ERRCODE_DUPLICATE_COLUMN), errmsg("column \"%s\" of relation \"%s\" already exists", colname, RelationGetRelationName(rel)))); } return true; } /* * Install a column's dependency on its datatype. */ static void add_column_datatype_dependency(Oid relid, int32 attnum, Oid typid) { ObjectAddress myself, referenced; myself.classId = RelationRelationId; myself.objectId = relid; myself.objectSubId = attnum; referenced.classId = TypeRelationId; referenced.objectId = typid; referenced.objectSubId = 0; recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL); } /* * Install a column's dependency on its collation. */ static void add_column_collation_dependency(Oid relid, int32 attnum, Oid collid) { ObjectAddress myself, referenced; /* We know the default collation is pinned, so don't bother recording it */ if (OidIsValid(collid) && collid != DEFAULT_COLLATION_OID) { myself.classId = RelationRelationId; myself.objectId = relid; myself.objectSubId = attnum; referenced.classId = CollationRelationId; referenced.objectId = collid; referenced.objectSubId = 0; recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL); } } /* * ALTER TABLE ALTER COLUMN DROP NOT NULL * * Return the address of the modified column. If the column was already * nullable, InvalidObjectAddress is returned. */ static ObjectAddress ATExecDropNotNull(Relation rel, const char *colName, bool recurse, LOCKMODE lockmode) { HeapTuple tuple; HeapTuple conTup; Form_pg_attribute attTup; AttrNumber attnum; Relation attr_rel; ObjectAddress address; /* * lookup the attribute */ attr_rel = table_open(AttributeRelationId, RowExclusiveLock); tuple = SearchSysCacheCopyAttName(RelationGetRelid(rel), colName); if (!HeapTupleIsValid(tuple)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" of relation \"%s\" does not exist", colName, RelationGetRelationName(rel)))); attTup = (Form_pg_attribute) GETSTRUCT(tuple); attnum = attTup->attnum; ObjectAddressSubSet(address, RelationRelationId, RelationGetRelid(rel), attnum); /* If the column is already nullable there's nothing to do. */ if (!attTup->attnotnull) { table_close(attr_rel, RowExclusiveLock); return InvalidObjectAddress; } /* Prevent them from altering a system attribute */ if (attnum <= 0) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter system column \"%s\"", colName))); if (attTup->attidentity) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("column \"%s\" of relation \"%s\" is an identity column", colName, RelationGetRelationName(rel)))); /* * If rel is partition, shouldn't drop NOT NULL if parent has the same. */ if (rel->rd_rel->relispartition) { Oid parentId = get_partition_parent(RelationGetRelid(rel), false); Relation parent = table_open(parentId, AccessShareLock); TupleDesc tupDesc = RelationGetDescr(parent); AttrNumber parent_attnum; parent_attnum = get_attnum(parentId, colName); if (TupleDescAttr(tupDesc, parent_attnum - 1)->attnotnull) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("column \"%s\" is marked NOT NULL in parent table", colName))); table_close(parent, AccessShareLock); } /* * Find the constraint that makes this column NOT NULL, and drop it. * dropconstraint_internal() resets attnotnull. */ conTup = findNotNullConstraintAttnum(RelationGetRelid(rel), attnum); if (conTup == NULL) elog(ERROR, "cache lookup failed for not-null constraint on column \"%s\" of relation \"%s\"", colName, RelationGetRelationName(rel)); /* The normal case: we have a pg_constraint row, remove it */ dropconstraint_internal(rel, conTup, DROP_RESTRICT, recurse, false, false, lockmode); heap_freetuple(conTup); InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), attnum); table_close(attr_rel, RowExclusiveLock); return address; } /* * set_attnotnull * Helper to update/validate the pg_attribute status of a not-null * constraint * * pg_attribute.attnotnull is set true, if it isn't already. * If queue_validation is true, also set up wqueue to validate the constraint. * wqueue may be given as NULL when validation is not needed (e.g., on table * creation). */ static void set_attnotnull(List **wqueue, Relation rel, AttrNumber attnum, bool queue_validation) { Form_pg_attribute attr; Assert(!queue_validation || wqueue); CheckAlterTableIsSafe(rel); /* * Exit quickly by testing attnotnull from the tupledesc's copy of the * attribute. */ attr = TupleDescAttr(RelationGetDescr(rel), attnum - 1); if (attr->attisdropped) return; if (!attr->attnotnull) { Relation attr_rel; HeapTuple tuple; attr_rel = table_open(AttributeRelationId, RowExclusiveLock); tuple = SearchSysCacheCopyAttNum(RelationGetRelid(rel), attnum); if (!HeapTupleIsValid(tuple)) elog(ERROR, "cache lookup failed for attribute %d of relation %u", attnum, RelationGetRelid(rel)); attr = (Form_pg_attribute) GETSTRUCT(tuple); attr->attnotnull = true; CatalogTupleUpdate(attr_rel, &tuple->t_self, tuple); /* * If the nullness isn't already proven by validated constraints, have * ALTER TABLE phase 3 test for it. */ if (queue_validation && wqueue && !NotNullImpliedByRelConstraints(rel, attr)) { AlteredTableInfo *tab; tab = ATGetQueueEntry(wqueue, rel); tab->verify_new_notnull = true; } CommandCounterIncrement(); table_close(attr_rel, RowExclusiveLock); heap_freetuple(tuple); } else { CacheInvalidateRelcache(rel); } } /* * ALTER TABLE ALTER COLUMN SET NOT NULL * * Add a not-null constraint to a single table and its children. Returns * the address of the constraint added to the parent relation, if one gets * added, or InvalidObjectAddress otherwise. * * We must recurse to child tables during execution, rather than using * ALTER TABLE's normal prep-time recursion. */ static ObjectAddress ATExecSetNotNull(List **wqueue, Relation rel, char *conName, char *colName, bool recurse, bool recursing, LOCKMODE lockmode) { HeapTuple tuple; AttrNumber attnum; ObjectAddress address; Constraint *constraint; CookedConstraint *ccon; List *cooked; bool is_no_inherit = false; /* Guard against stack overflow due to overly deep inheritance tree. */ check_stack_depth(); /* At top level, permission check was done in ATPrepCmd, else do it */ if (recursing) { ATSimplePermissions(AT_AddConstraint, rel, ATT_PARTITIONED_TABLE | ATT_TABLE | ATT_FOREIGN_TABLE); Assert(conName != NULL); } attnum = get_attnum(RelationGetRelid(rel), colName); if (attnum == InvalidAttrNumber) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" of relation \"%s\" does not exist", colName, RelationGetRelationName(rel)))); /* Prevent them from altering a system attribute */ if (attnum <= 0) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter system column \"%s\"", colName))); /* See if there's already a constraint */ tuple = findNotNullConstraintAttnum(RelationGetRelid(rel), attnum); if (HeapTupleIsValid(tuple)) { Form_pg_constraint conForm = (Form_pg_constraint) GETSTRUCT(tuple); bool changed = false; /* * Don't let a NO INHERIT constraint be changed into inherit. */ if (conForm->connoinherit && recurse) ereport(ERROR, errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot change NO INHERIT status of NOT NULL constraint \"%s\" on relation \"%s\"", NameStr(conForm->conname), RelationGetRelationName(rel))); /* * If we find an appropriate constraint, we're almost done, but just * need to change some properties on it: if we're recursing, increment * coninhcount; if not, set conislocal if not already set. */ if (recursing) { if (pg_add_s16_overflow(conForm->coninhcount, 1, &conForm->coninhcount)) ereport(ERROR, errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED), errmsg("too many inheritance parents")); changed = true; } else if (!conForm->conislocal) { conForm->conislocal = true; changed = true; } else if (!conForm->convalidated) { /* * Flip attnotnull and convalidated, and also validate the * constraint. */ return ATExecValidateConstraint(wqueue, rel, NameStr(conForm->conname), recurse, recursing, lockmode); } if (changed) { Relation constr_rel; constr_rel = table_open(ConstraintRelationId, RowExclusiveLock); CatalogTupleUpdate(constr_rel, &tuple->t_self, tuple); ObjectAddressSet(address, ConstraintRelationId, conForm->oid); table_close(constr_rel, RowExclusiveLock); } if (changed) return address; else return InvalidObjectAddress; } /* * If we're asked not to recurse, and children exist, raise an error for * partitioned tables. For inheritance, we act as if NO INHERIT had been * specified. */ if (!recurse && find_inheritance_children(RelationGetRelid(rel), NoLock) != NIL) { if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) ereport(ERROR, errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("constraint must be added to child tables too"), errhint("Do not specify the ONLY keyword.")); else is_no_inherit = true; } /* * No constraint exists; we must add one. First determine a name to use, * if we haven't already. */ if (!recursing) { Assert(conName == NULL); conName = ChooseConstraintName(RelationGetRelationName(rel), colName, "not_null", RelationGetNamespace(rel), NIL); } constraint = makeNotNullConstraint(makeString(colName)); constraint->is_no_inherit = is_no_inherit; constraint->conname = conName; /* and do it */ cooked = AddRelationNewConstraints(rel, NIL, list_make1(constraint), false, !recursing, false, NULL); ccon = linitial(cooked); ObjectAddressSet(address, ConstraintRelationId, ccon->conoid); /* Mark pg_attribute.attnotnull for the column and queue validation */ set_attnotnull(wqueue, rel, attnum, true); InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), attnum); /* * Recurse to propagate the constraint to children that don't have one. */ if (recurse) { List *children; children = find_inheritance_children(RelationGetRelid(rel), lockmode); foreach_oid(childoid, children) { Relation childrel = table_open(childoid, NoLock); CommandCounterIncrement(); ATExecSetNotNull(wqueue, childrel, conName, colName, recurse, true, lockmode); table_close(childrel, NoLock); } } return address; } /* * NotNullImpliedByRelConstraints * Does rel's existing constraints imply NOT NULL for the given attribute? */ static bool NotNullImpliedByRelConstraints(Relation rel, Form_pg_attribute attr) { NullTest *nnulltest = makeNode(NullTest); nnulltest->arg = (Expr *) makeVar(1, attr->attnum, attr->atttypid, attr->atttypmod, attr->attcollation, 0); nnulltest->nulltesttype = IS_NOT_NULL; /* * argisrow = false is correct even for a composite column, because * attnotnull does not represent a SQL-spec IS NOT NULL test in such a * case, just IS DISTINCT FROM NULL. */ nnulltest->argisrow = false; nnulltest->location = -1; if (ConstraintImpliedByRelConstraint(rel, list_make1(nnulltest), NIL)) { ereport(DEBUG1, (errmsg_internal("existing constraints on column \"%s.%s\" are sufficient to prove that it does not contain nulls", RelationGetRelationName(rel), NameStr(attr->attname)))); return true; } return false; } /* * ALTER TABLE ALTER COLUMN SET/DROP DEFAULT * * Return the address of the affected column. */ static ObjectAddress ATExecColumnDefault(Relation rel, const char *colName, Node *newDefault, LOCKMODE lockmode) { TupleDesc tupdesc = RelationGetDescr(rel); AttrNumber attnum; ObjectAddress address; /* * get the number of the attribute */ attnum = get_attnum(RelationGetRelid(rel), colName); if (attnum == InvalidAttrNumber) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" of relation \"%s\" does not exist", colName, RelationGetRelationName(rel)))); /* Prevent them from altering a system attribute */ if (attnum <= 0) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter system column \"%s\"", colName))); if (TupleDescAttr(tupdesc, attnum - 1)->attidentity) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("column \"%s\" of relation \"%s\" is an identity column", colName, RelationGetRelationName(rel)), /* translator: %s is an SQL ALTER command */ newDefault ? 0 : errhint("Use %s instead.", "ALTER TABLE ... ALTER COLUMN ... DROP IDENTITY"))); if (TupleDescAttr(tupdesc, attnum - 1)->attgenerated) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("column \"%s\" of relation \"%s\" is a generated column", colName, RelationGetRelationName(rel)), newDefault ? /* translator: %s is an SQL ALTER command */ errhint("Use %s instead.", "ALTER TABLE ... ALTER COLUMN ... SET EXPRESSION") : (TupleDescAttr(tupdesc, attnum - 1)->attgenerated == ATTRIBUTE_GENERATED_STORED ? errhint("Use %s instead.", "ALTER TABLE ... ALTER COLUMN ... DROP EXPRESSION") : 0))); /* * Remove any old default for the column. We use RESTRICT here for * safety, but at present we do not expect anything to depend on the * default. * * We treat removing the existing default as an internal operation when it * is preparatory to adding a new default, but as a user-initiated * operation when the user asked for a drop. */ RemoveAttrDefault(RelationGetRelid(rel), attnum, DROP_RESTRICT, false, newDefault != NULL); if (newDefault) { /* SET DEFAULT */ RawColumnDefault *rawEnt; rawEnt = palloc_object(RawColumnDefault); rawEnt->attnum = attnum; rawEnt->raw_default = newDefault; rawEnt->generated = '\0'; /* * This function is intended for CREATE TABLE, so it processes a * _list_ of defaults, but we just do one. */ AddRelationNewConstraints(rel, list_make1(rawEnt), NIL, false, true, false, NULL); } ObjectAddressSubSet(address, RelationRelationId, RelationGetRelid(rel), attnum); return address; } /* * Add a pre-cooked default expression. * * Return the address of the affected column. */ static ObjectAddress ATExecCookedColumnDefault(Relation rel, AttrNumber attnum, Node *newDefault) { ObjectAddress address; /* * This is used for a cooked default copied by CREATE TABLE ... LIKE, * which adds new type dependencies. Such a default doesn't go through * AddRelationNewConstraints(), and StoreAttrDefault() leaves the * privilege checks to its caller, so we must check for USAGE on the types * here. */ CheckUsageOnTypesInSingleRelExpr(newDefault, RelationGetRelid(rel), GetUserId()); /* * Remove any old default for the column. We use RESTRICT here for * safety, but at present we do not expect anything to depend on the * default. (In ordinary cases, there could not be a default in place * anyway, but it's possible when combining LIKE with inheritance.) */ RemoveAttrDefault(RelationGetRelid(rel), attnum, DROP_RESTRICT, false, true); (void) StoreAttrDefault(rel, attnum, newDefault, true); ObjectAddressSubSet(address, RelationRelationId, RelationGetRelid(rel), attnum); return address; } /* * ALTER TABLE ALTER COLUMN ADD IDENTITY * * Return the address of the affected column. */ static ObjectAddress ATExecAddIdentity(Relation rel, const char *colName, Node *def, LOCKMODE lockmode, bool recurse, bool recursing) { Relation attrelation; HeapTuple tuple; Form_pg_attribute attTup; AttrNumber attnum; ObjectAddress address; ColumnDef *cdef = castNode(ColumnDef, def); bool ispartitioned; ispartitioned = (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE); if (ispartitioned && !recurse) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("cannot add identity to a column of only the partitioned table"), errhint("Do not specify the ONLY keyword."))); if (rel->rd_rel->relispartition && !recursing) ereport(ERROR, errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("cannot add identity to a column of a partition")); attrelation = table_open(AttributeRelationId, RowExclusiveLock); tuple = SearchSysCacheCopyAttName(RelationGetRelid(rel), colName); if (!HeapTupleIsValid(tuple)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" of relation \"%s\" does not exist", colName, RelationGetRelationName(rel)))); attTup = (Form_pg_attribute) GETSTRUCT(tuple); attnum = attTup->attnum; /* Can't alter a system attribute */ if (attnum <= 0) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter system column \"%s\"", colName))); /* * Creating a column as identity implies NOT NULL, so adding the identity * to an existing column that is not NOT NULL would create a state that * cannot be reproduced without contortions. */ if (!attTup->attnotnull) ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("column \"%s\" of relation \"%s\" must be declared NOT NULL before identity can be added", colName, RelationGetRelationName(rel)))); /* * On the other hand, if a not-null constraint exists, then verify that * it's compatible. */ if (attTup->attnotnull) { HeapTuple contup; Form_pg_constraint conForm; contup = findNotNullConstraintAttnum(RelationGetRelid(rel), attnum); if (!HeapTupleIsValid(contup)) elog(ERROR, "cache lookup failed for not-null constraint on column \"%s\" of relation \"%s\"", colName, RelationGetRelationName(rel)); conForm = (Form_pg_constraint) GETSTRUCT(contup); if (!conForm->convalidated) ereport(ERROR, errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("incompatible NOT VALID constraint \"%s\" on relation \"%s\"", NameStr(conForm->conname), RelationGetRelationName(rel)), errhint("You might need to validate it using %s.", "ALTER TABLE ... VALIDATE CONSTRAINT")); } if (attTup->attidentity) ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("column \"%s\" of relation \"%s\" is already an identity column", colName, RelationGetRelationName(rel)))); if (attTup->atthasdef) ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("column \"%s\" of relation \"%s\" already has a default value", colName, RelationGetRelationName(rel)))); attTup->attidentity = cdef->identity; CatalogTupleUpdate(attrelation, &tuple->t_self, tuple); InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), attTup->attnum); ObjectAddressSubSet(address, RelationRelationId, RelationGetRelid(rel), attnum); heap_freetuple(tuple); table_close(attrelation, RowExclusiveLock); /* * Recurse to propagate the identity column to partitions. Identity is * not inherited in regular inheritance children. */ if (recurse && ispartitioned) { List *children; ListCell *lc; children = find_inheritance_children(RelationGetRelid(rel), lockmode); foreach(lc, children) { Relation childrel; childrel = table_open(lfirst_oid(lc), NoLock); ATExecAddIdentity(childrel, colName, def, lockmode, recurse, true); table_close(childrel, NoLock); } } return address; } /* * ALTER TABLE ALTER COLUMN SET { GENERATED or sequence options } * * Return the address of the affected column. */ static ObjectAddress ATExecSetIdentity(Relation rel, const char *colName, Node *def, LOCKMODE lockmode, bool recurse, bool recursing) { ListCell *option; DefElem *generatedEl = NULL; HeapTuple tuple; Form_pg_attribute attTup; AttrNumber attnum; Relation attrelation; ObjectAddress address; bool ispartitioned; ispartitioned = (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE); if (ispartitioned && !recurse) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("cannot change identity column of only the partitioned table"), errhint("Do not specify the ONLY keyword."))); if (rel->rd_rel->relispartition && !recursing) ereport(ERROR, errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("cannot change identity column of a partition")); foreach(option, castNode(List, def)) { DefElem *defel = lfirst_node(DefElem, option); if (strcmp(defel->defname, "generated") == 0) { if (generatedEl) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("conflicting or redundant options"))); generatedEl = defel; } else elog(ERROR, "option \"%s\" not recognized", defel->defname); } /* * Even if there is nothing to change here, we run all the checks. There * will be a subsequent ALTER SEQUENCE that relies on everything being * there. */ attrelation = table_open(AttributeRelationId, RowExclusiveLock); tuple = SearchSysCacheCopyAttName(RelationGetRelid(rel), colName); if (!HeapTupleIsValid(tuple)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" of relation \"%s\" does not exist", colName, RelationGetRelationName(rel)))); attTup = (Form_pg_attribute) GETSTRUCT(tuple); attnum = attTup->attnum; if (attnum <= 0) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter system column \"%s\"", colName))); if (!attTup->attidentity) ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("column \"%s\" of relation \"%s\" is not an identity column", colName, RelationGetRelationName(rel)))); if (generatedEl) { attTup->attidentity = defGetInt32(generatedEl); CatalogTupleUpdate(attrelation, &tuple->t_self, tuple); InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), attTup->attnum); ObjectAddressSubSet(address, RelationRelationId, RelationGetRelid(rel), attnum); } else address = InvalidObjectAddress; heap_freetuple(tuple); table_close(attrelation, RowExclusiveLock); /* * Recurse to propagate the identity change to partitions. Identity is not * inherited in regular inheritance children. */ if (generatedEl && recurse && ispartitioned) { List *children; ListCell *lc; children = find_inheritance_children(RelationGetRelid(rel), lockmode); foreach(lc, children) { Relation childrel; childrel = table_open(lfirst_oid(lc), NoLock); ATExecSetIdentity(childrel, colName, def, lockmode, recurse, true); table_close(childrel, NoLock); } } return address; } /* * ALTER TABLE ALTER COLUMN DROP IDENTITY * * Return the address of the affected column. */ static ObjectAddress ATExecDropIdentity(Relation rel, const char *colName, bool missing_ok, LOCKMODE lockmode, bool recurse, bool recursing) { HeapTuple tuple; Form_pg_attribute attTup; AttrNumber attnum; Relation attrelation; ObjectAddress address; Oid seqid; ObjectAddress seqaddress; bool ispartitioned; ispartitioned = (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE); if (ispartitioned && !recurse) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("cannot drop identity from a column of only the partitioned table"), errhint("Do not specify the ONLY keyword."))); if (rel->rd_rel->relispartition && !recursing) ereport(ERROR, errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("cannot drop identity from a column of a partition")); attrelation = table_open(AttributeRelationId, RowExclusiveLock); tuple = SearchSysCacheCopyAttName(RelationGetRelid(rel), colName); if (!HeapTupleIsValid(tuple)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" of relation \"%s\" does not exist", colName, RelationGetRelationName(rel)))); attTup = (Form_pg_attribute) GETSTRUCT(tuple); attnum = attTup->attnum; if (attnum <= 0) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter system column \"%s\"", colName))); if (!attTup->attidentity) { if (!missing_ok) ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("column \"%s\" of relation \"%s\" is not an identity column", colName, RelationGetRelationName(rel)))); else { ereport(NOTICE, (errmsg("column \"%s\" of relation \"%s\" is not an identity column, skipping", colName, RelationGetRelationName(rel)))); heap_freetuple(tuple); table_close(attrelation, RowExclusiveLock); return InvalidObjectAddress; } } attTup->attidentity = '\0'; CatalogTupleUpdate(attrelation, &tuple->t_self, tuple); InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), attTup->attnum); ObjectAddressSubSet(address, RelationRelationId, RelationGetRelid(rel), attnum); heap_freetuple(tuple); table_close(attrelation, RowExclusiveLock); /* * Recurse to drop the identity from column in partitions. Identity is * not inherited in regular inheritance children so ignore them. */ if (recurse && ispartitioned) { List *children; ListCell *lc; children = find_inheritance_children(RelationGetRelid(rel), lockmode); foreach(lc, children) { Relation childrel; childrel = table_open(lfirst_oid(lc), NoLock); ATExecDropIdentity(childrel, colName, false, lockmode, recurse, true); table_close(childrel, NoLock); } } if (!recursing) { /* drop the internal sequence */ seqid = getIdentitySequence(rel, attnum, false); deleteDependencyRecordsForClass(RelationRelationId, seqid, RelationRelationId, DEPENDENCY_INTERNAL); CommandCounterIncrement(); seqaddress.classId = RelationRelationId; seqaddress.objectId = seqid; seqaddress.objectSubId = 0; performDeletion(&seqaddress, DROP_RESTRICT, PERFORM_DELETION_INTERNAL); } return address; } /* * ALTER TABLE ALTER COLUMN SET EXPRESSION * * Return the address of the affected column. */ static ObjectAddress ATExecSetExpression(AlteredTableInfo *tab, Relation rel, const char *colName, Node *newExpr, LOCKMODE lockmode) { HeapTuple tuple; Form_pg_attribute attTup; AttrNumber attnum; char attgenerated; bool rewrite; Oid attrdefoid; ObjectAddress address; Expr *defval; NewColumnValue *newval; RawColumnDefault *rawEnt; tuple = SearchSysCacheAttName(RelationGetRelid(rel), colName); if (!HeapTupleIsValid(tuple)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" of relation \"%s\" does not exist", colName, RelationGetRelationName(rel)))); attTup = (Form_pg_attribute) GETSTRUCT(tuple); attnum = attTup->attnum; if (attnum <= 0) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter system column \"%s\"", colName))); attgenerated = attTup->attgenerated; if (!attgenerated) ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("column \"%s\" of relation \"%s\" is not a generated column", colName, RelationGetRelationName(rel)))); if (attgenerated == ATTRIBUTE_GENERATED_VIRTUAL && attTup->attnotnull) tab->verify_new_notnull = true; /* * We need to prevent this because a change of expression could affect a * row filter and inject expressions that are not permitted in a row * filter. XXX We could try to have a more precise check to catch only * publications with row filters, or even re-verify the row filter * expressions. */ if (attgenerated == ATTRIBUTE_GENERATED_VIRTUAL && GetRelationIncludedPublications(RelationGetRelid(rel)) != NIL) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("ALTER TABLE / SET EXPRESSION is not supported for virtual generated columns in tables that are part of a publication"), errdetail("Column \"%s\" of relation \"%s\" is a virtual generated column.", colName, RelationGetRelationName(rel)))); rewrite = (attgenerated == ATTRIBUTE_GENERATED_STORED); ReleaseSysCache(tuple); if (rewrite) { /* * Clear all the missing values if we're rewriting the table, since * this renders them pointless. */ RelationClearMissing(rel); /* make sure we don't conflict with later attribute modifications */ CommandCounterIncrement(); } /* * Find everything that depends on the column (constraints, indexes, etc), * and record enough information to let us recreate the objects. */ RememberAllDependentForRebuilding(tab, AT_SetExpression, rel, attnum, colName); /* * Find whole-row referenced objects that depend on the column * (constraints, indexes, etc.), and record enough information to let us * recreate the objects. */ RememberWholeRowDependentForRebuilding(tab, AT_SetExpression, rel); /* * Drop the dependency records of the GENERATED expression, in particular * its INTERNAL dependency on the column, which would otherwise cause * dependency.c to refuse to perform the deletion. */ attrdefoid = GetAttrDefaultOid(RelationGetRelid(rel), attnum); if (!OidIsValid(attrdefoid)) elog(ERROR, "could not find attrdef tuple for relation %u attnum %d", RelationGetRelid(rel), attnum); (void) deleteDependencyRecordsFor(AttrDefaultRelationId, attrdefoid, false); /* Make above changes visible */ CommandCounterIncrement(); /* * Get rid of the GENERATED expression itself. We use RESTRICT here for * safety, but at present we do not expect anything to depend on the * expression. */ RemoveAttrDefault(RelationGetRelid(rel), attnum, DROP_RESTRICT, false, false); /* Prepare to store the new expression, in the catalogs */ rawEnt = palloc_object(RawColumnDefault); rawEnt->attnum = attnum; rawEnt->raw_default = newExpr; rawEnt->generated = attgenerated; /* Store the generated expression */ AddRelationNewConstraints(rel, list_make1(rawEnt), NIL, false, true, false, NULL); /* Make above new expression visible */ CommandCounterIncrement(); if (rewrite) { /* Prepare for table rewrite */ defval = (Expr *) build_column_default(rel, attnum); newval = palloc0_object(NewColumnValue); newval->attnum = attnum; newval->expr = expression_planner(defval); newval->is_generated = true; tab->newvals = lappend(tab->newvals, newval); tab->rewrite |= AT_REWRITE_DEFAULT_VAL; } /* Drop any pg_statistic entry for the column */ RemoveStatistics(RelationGetRelid(rel), attnum); InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), attnum); ObjectAddressSubSet(address, RelationRelationId, RelationGetRelid(rel), attnum); return address; } /* * ALTER TABLE ALTER COLUMN DROP EXPRESSION */ static void ATPrepDropExpression(Relation rel, AlterTableCmd *cmd, bool recurse, bool recursing, LOCKMODE lockmode) { /* * Reject ONLY if there are child tables -- but only, of course, at the * top of the tree, otherwise it'd be impossible to run this command with * trees deeper than two levels. Caller already got lock. */ if (!recurse && !recursing && find_inheritance_children(RelationGetRelid(rel), NoLock)) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("ALTER TABLE / DROP EXPRESSION must be applied to child tables too"))); /* * Cannot drop generation expression from inherited columns. */ if (!recursing) { HeapTuple tuple; Form_pg_attribute attTup; tuple = SearchSysCacheCopyAttName(RelationGetRelid(rel), cmd->name); if (!HeapTupleIsValid(tuple)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" of relation \"%s\" does not exist", cmd->name, RelationGetRelationName(rel)))); attTup = (Form_pg_attribute) GETSTRUCT(tuple); if (attTup->attinhcount > 0) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("cannot drop generation expression from inherited column"))); } } /* * Return the address of the affected column. */ static ObjectAddress ATExecDropExpression(Relation rel, const char *colName, bool missing_ok, LOCKMODE lockmode) { HeapTuple tuple; Form_pg_attribute attTup; AttrNumber attnum; Relation attrelation; Oid attrdefoid; ObjectAddress address; attrelation = table_open(AttributeRelationId, RowExclusiveLock); tuple = SearchSysCacheCopyAttName(RelationGetRelid(rel), colName); if (!HeapTupleIsValid(tuple)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" of relation \"%s\" does not exist", colName, RelationGetRelationName(rel)))); attTup = (Form_pg_attribute) GETSTRUCT(tuple); attnum = attTup->attnum; if (attnum <= 0) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter system column \"%s\"", colName))); /* * TODO: This could be done, but it would need a table rewrite to * materialize the generated values. Note that for the time being, we * still error with missing_ok, so that we don't silently leave the column * as generated. */ if (attTup->attgenerated == ATTRIBUTE_GENERATED_VIRTUAL) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("ALTER TABLE / DROP EXPRESSION is not supported for virtual generated columns"), errdetail("Column \"%s\" of relation \"%s\" is a virtual generated column.", colName, RelationGetRelationName(rel)))); if (!attTup->attgenerated) { if (!missing_ok) ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("column \"%s\" of relation \"%s\" is not a generated column", colName, RelationGetRelationName(rel)))); else { ereport(NOTICE, (errmsg("column \"%s\" of relation \"%s\" is not a generated column, skipping", colName, RelationGetRelationName(rel)))); heap_freetuple(tuple); table_close(attrelation, RowExclusiveLock); return InvalidObjectAddress; } } /* * Mark the column as no longer generated. (The atthasdef flag needs to * get cleared too, but RemoveAttrDefault will handle that.) */ attTup->attgenerated = '\0'; CatalogTupleUpdate(attrelation, &tuple->t_self, tuple); InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), attnum); heap_freetuple(tuple); table_close(attrelation, RowExclusiveLock); /* * Drop the dependency records of the GENERATED expression, in particular * its INTERNAL dependency on the column, which would otherwise cause * dependency.c to refuse to perform the deletion. */ attrdefoid = GetAttrDefaultOid(RelationGetRelid(rel), attnum); if (!OidIsValid(attrdefoid)) elog(ERROR, "could not find attrdef tuple for relation %u attnum %d", RelationGetRelid(rel), attnum); (void) deleteDependencyRecordsFor(AttrDefaultRelationId, attrdefoid, false); /* Make above changes visible */ CommandCounterIncrement(); /* * Get rid of the GENERATED expression itself. We use RESTRICT here for * safety, but at present we do not expect anything to depend on the * default. */ RemoveAttrDefault(RelationGetRelid(rel), attnum, DROP_RESTRICT, false, false); ObjectAddressSubSet(address, RelationRelationId, RelationGetRelid(rel), attnum); return address; } /* * ALTER TABLE ALTER COLUMN SET STATISTICS * * Return value is the address of the modified column */ static ObjectAddress ATExecSetStatistics(Relation rel, const char *colName, int16 colNum, Node *newValue, LOCKMODE lockmode) { int newtarget = 0; bool newtarget_default; Relation attrelation; HeapTuple tuple, newtuple; Form_pg_attribute attrtuple; AttrNumber attnum; ObjectAddress address; Datum repl_val[Natts_pg_attribute]; bool repl_null[Natts_pg_attribute]; bool repl_repl[Natts_pg_attribute]; /* * We allow referencing columns by numbers only for indexes, since table * column numbers could contain gaps if columns are later dropped. */ if (rel->rd_rel->relkind != RELKIND_INDEX && rel->rd_rel->relkind != RELKIND_PARTITIONED_INDEX && !colName) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot refer to non-index column by number"))); /* -1 was used in previous versions for the default setting */ if (newValue && intVal(newValue) != -1) { newtarget = intVal(newValue); newtarget_default = false; } else newtarget_default = true; if (!newtarget_default) { /* * Limit target to a sane range */ if (newtarget < 0) { ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("statistics target %d is too low", newtarget))); } else if (newtarget > MAX_STATISTICS_TARGET) { newtarget = MAX_STATISTICS_TARGET; ereport(WARNING, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("lowering statistics target to %d", newtarget))); } } attrelation = table_open(AttributeRelationId, RowExclusiveLock); if (colName) { tuple = SearchSysCacheAttName(RelationGetRelid(rel), colName); if (!HeapTupleIsValid(tuple)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" of relation \"%s\" does not exist", colName, RelationGetRelationName(rel)))); } else { tuple = SearchSysCacheAttNum(RelationGetRelid(rel), colNum); if (!HeapTupleIsValid(tuple)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column number %d of relation \"%s\" does not exist", colNum, RelationGetRelationName(rel)))); } attrtuple = (Form_pg_attribute) GETSTRUCT(tuple); attnum = attrtuple->attnum; if (attnum <= 0) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter system column \"%s\"", colName))); /* * Prevent this as long as the ANALYZE code skips virtual generated * columns. */ if (attrtuple->attgenerated == ATTRIBUTE_GENERATED_VIRTUAL) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter statistics on virtual generated column \"%s\"", colName))); if (rel->rd_rel->relkind == RELKIND_INDEX || rel->rd_rel->relkind == RELKIND_PARTITIONED_INDEX) { if (attnum > rel->rd_index->indnkeyatts) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter statistics on included column \"%s\" of index \"%s\"", NameStr(attrtuple->attname), RelationGetRelationName(rel)))); else if (rel->rd_index->indkey.values[attnum - 1] != 0) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter statistics on non-expression column \"%s\" of index \"%s\"", NameStr(attrtuple->attname), RelationGetRelationName(rel)), errhint("Alter statistics on table column instead."))); } /* Build new tuple. */ memset(repl_null, false, sizeof(repl_null)); memset(repl_repl, false, sizeof(repl_repl)); if (!newtarget_default) repl_val[Anum_pg_attribute_attstattarget - 1] = Int16GetDatum(newtarget); else repl_null[Anum_pg_attribute_attstattarget - 1] = true; repl_repl[Anum_pg_attribute_attstattarget - 1] = true; newtuple = heap_modify_tuple(tuple, RelationGetDescr(attrelation), repl_val, repl_null, repl_repl); CatalogTupleUpdate(attrelation, &tuple->t_self, newtuple); InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), attrtuple->attnum); ObjectAddressSubSet(address, RelationRelationId, RelationGetRelid(rel), attnum); heap_freetuple(newtuple); ReleaseSysCache(tuple); table_close(attrelation, RowExclusiveLock); return address; } /* * Return value is the address of the modified column */ static ObjectAddress ATExecSetOptions(Relation rel, const char *colName, Node *options, bool isReset, LOCKMODE lockmode) { Relation attrelation; HeapTuple tuple, newtuple; Form_pg_attribute attrtuple; AttrNumber attnum; Datum datum, newOptions; bool isnull; ObjectAddress address; Datum repl_val[Natts_pg_attribute]; bool repl_null[Natts_pg_attribute]; bool repl_repl[Natts_pg_attribute]; attrelation = table_open(AttributeRelationId, RowExclusiveLock); tuple = SearchSysCacheAttName(RelationGetRelid(rel), colName); if (!HeapTupleIsValid(tuple)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" of relation \"%s\" does not exist", colName, RelationGetRelationName(rel)))); attrtuple = (Form_pg_attribute) GETSTRUCT(tuple); attnum = attrtuple->attnum; if (attnum <= 0) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter system column \"%s\"", colName))); /* Generate new proposed attoptions (text array) */ datum = SysCacheGetAttr(ATTNAME, tuple, Anum_pg_attribute_attoptions, &isnull); newOptions = transformRelOptions(isnull ? (Datum) 0 : datum, castNode(List, options), NULL, NULL, false, isReset); /* Validate new options */ (void) attribute_reloptions(newOptions, true); /* Build new tuple. */ memset(repl_null, false, sizeof(repl_null)); memset(repl_repl, false, sizeof(repl_repl)); if (newOptions != (Datum) 0) repl_val[Anum_pg_attribute_attoptions - 1] = newOptions; else repl_null[Anum_pg_attribute_attoptions - 1] = true; repl_repl[Anum_pg_attribute_attoptions - 1] = true; newtuple = heap_modify_tuple(tuple, RelationGetDescr(attrelation), repl_val, repl_null, repl_repl); /* Update system catalog. */ CatalogTupleUpdate(attrelation, &newtuple->t_self, newtuple); InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), attrtuple->attnum); ObjectAddressSubSet(address, RelationRelationId, RelationGetRelid(rel), attnum); heap_freetuple(newtuple); ReleaseSysCache(tuple); table_close(attrelation, RowExclusiveLock); return address; } /* * Helper function for ATExecSetStorage and ATExecSetCompression * * Set the attstorage and/or attcompression fields for index columns * associated with the specified table column. */ static void SetIndexStorageProperties(Relation rel, Relation attrelation, AttrNumber attnum, bool setstorage, char newstorage, bool setcompression, char newcompression, LOCKMODE lockmode) { ListCell *lc; foreach(lc, RelationGetIndexList(rel)) { Oid indexoid = lfirst_oid(lc); Relation indrel; AttrNumber indattnum = 0; HeapTuple tuple; indrel = index_open(indexoid, lockmode); for (int i = 0; i < indrel->rd_index->indnatts; i++) { if (indrel->rd_index->indkey.values[i] == attnum) { indattnum = i + 1; break; } } if (indattnum == 0) { index_close(indrel, lockmode); continue; } tuple = SearchSysCacheCopyAttNum(RelationGetRelid(indrel), indattnum); if (HeapTupleIsValid(tuple)) { Form_pg_attribute attrtuple = (Form_pg_attribute) GETSTRUCT(tuple); if (setstorage) attrtuple->attstorage = newstorage; if (setcompression) attrtuple->attcompression = newcompression; CatalogTupleUpdate(attrelation, &tuple->t_self, tuple); InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), attrtuple->attnum); heap_freetuple(tuple); } index_close(indrel, lockmode); } } /* * ALTER TABLE ALTER COLUMN SET STORAGE * * Return value is the address of the modified column */ static ObjectAddress ATExecSetStorage(Relation rel, const char *colName, Node *newValue, LOCKMODE lockmode) { Relation attrelation; HeapTuple tuple; Form_pg_attribute attrtuple; AttrNumber attnum; ObjectAddress address; attrelation = table_open(AttributeRelationId, RowExclusiveLock); tuple = SearchSysCacheCopyAttName(RelationGetRelid(rel), colName); if (!HeapTupleIsValid(tuple)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" of relation \"%s\" does not exist", colName, RelationGetRelationName(rel)))); attrtuple = (Form_pg_attribute) GETSTRUCT(tuple); attnum = attrtuple->attnum; if (attnum <= 0) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter system column \"%s\"", colName))); attrtuple->attstorage = GetAttributeStorage(attrtuple->atttypid, strVal(newValue)); CatalogTupleUpdate(attrelation, &tuple->t_self, tuple); InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), attrtuple->attnum); /* * Apply the change to indexes as well (only for simple index columns, * matching behavior of index.c ConstructTupleDescriptor()). */ SetIndexStorageProperties(rel, attrelation, attnum, true, attrtuple->attstorage, false, 0, lockmode); heap_freetuple(tuple); table_close(attrelation, RowExclusiveLock); ObjectAddressSubSet(address, RelationRelationId, RelationGetRelid(rel), attnum); return address; } /* * ALTER TABLE DROP COLUMN * * DROP COLUMN cannot use the normal ALTER TABLE recursion mechanism, * because we have to decide at runtime whether to recurse or not depending * on whether attinhcount goes to zero or not. (We can't check this in a * static pre-pass because it won't handle multiple inheritance situations * correctly.) */ static void ATPrepDropColumn(List **wqueue, Relation rel, bool recurse, bool recursing, AlterTableCmd *cmd, LOCKMODE lockmode, AlterTableUtilityContext *context) { if (rel->rd_rel->reloftype && !recursing) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot drop column from typed table"))); if (rel->rd_rel->relkind == RELKIND_COMPOSITE_TYPE) ATTypedTableRecursion(wqueue, rel, cmd, lockmode, context); if (recurse) cmd->recurse = true; } /* * Drops column 'colName' from relation 'rel' and returns the address of the * dropped column. The column is also dropped (or marked as no longer * inherited from relation) from the relation's inheritance children, if any. * * In the recursive invocations for inheritance child relations, instead of * dropping the column directly (if to be dropped at all), its object address * is added to 'addrs', which must be non-NULL in such invocations. All * columns are dropped at the same time after all the children have been * checked recursively. */ static ObjectAddress ATExecDropColumn(List **wqueue, Relation rel, const char *colName, DropBehavior behavior, bool recurse, bool recursing, bool missing_ok, LOCKMODE lockmode, ObjectAddresses *addrs) { HeapTuple tuple; Form_pg_attribute targetatt; AttrNumber attnum; List *children; ObjectAddress object; bool is_expr; /* At top level, permission check was done in ATPrepCmd, else do it */ if (recursing) ATSimplePermissions(AT_DropColumn, rel, ATT_TABLE | ATT_PARTITIONED_TABLE | ATT_FOREIGN_TABLE); /* Initialize addrs on the first invocation */ Assert(!recursing || addrs != NULL); /* since this function recurses, it could be driven to stack overflow */ check_stack_depth(); if (!recursing) addrs = new_object_addresses(); /* * get the number of the attribute */ tuple = SearchSysCacheAttName(RelationGetRelid(rel), colName); if (!HeapTupleIsValid(tuple)) { if (!missing_ok) { ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" of relation \"%s\" does not exist", colName, RelationGetRelationName(rel)))); } else { ereport(NOTICE, (errmsg("column \"%s\" of relation \"%s\" does not exist, skipping", colName, RelationGetRelationName(rel)))); return InvalidObjectAddress; } } targetatt = (Form_pg_attribute) GETSTRUCT(tuple); attnum = targetatt->attnum; /* Can't drop a system attribute */ if (attnum <= 0) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot drop system column \"%s\"", colName))); /* * Don't drop inherited columns, unless recursing (presumably from a drop * of the parent column) */ if (targetatt->attinhcount > 0 && !recursing) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("cannot drop inherited column \"%s\"", colName))); /* * Don't drop columns used in the partition key, either. (If we let this * go through, the key column's dependencies would cause a cascaded drop * of the whole table, which is surely not what the user expected.) */ if (has_partition_attrs(rel, bms_make_singleton(attnum - FirstLowInvalidHeapAttributeNumber), &is_expr)) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("cannot drop column \"%s\" because it is part of the partition key of relation \"%s\"", colName, RelationGetRelationName(rel)))); ReleaseSysCache(tuple); /* * Propagate to children as appropriate. Unlike most other ALTER * routines, we have to do this one level of recursion at a time; we can't * use find_all_inheritors to do it in one pass. */ children = find_inheritance_children(RelationGetRelid(rel), lockmode); if (children) { Relation attr_rel; ListCell *child; /* * In case of a partitioned table, the column must be dropped from the * partitions as well. */ if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE && !recurse) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("cannot drop column from only the partitioned table when partitions exist"), errhint("Do not specify the ONLY keyword."))); attr_rel = table_open(AttributeRelationId, RowExclusiveLock); foreach(child, children) { Oid childrelid = lfirst_oid(child); Relation childrel; Form_pg_attribute childatt; /* find_inheritance_children already got lock */ childrel = table_open(childrelid, NoLock); CheckAlterTableIsSafe(childrel); tuple = SearchSysCacheCopyAttName(childrelid, colName); if (!HeapTupleIsValid(tuple)) /* shouldn't happen */ elog(ERROR, "cache lookup failed for attribute \"%s\" of relation %u", colName, childrelid); childatt = (Form_pg_attribute) GETSTRUCT(tuple); if (childatt->attinhcount <= 0) /* shouldn't happen */ elog(ERROR, "relation %u has non-inherited attribute \"%s\"", childrelid, colName); if (recurse) { /* * If the child column has other definition sources, just * decrement its inheritance count; if not, recurse to delete * it. */ if (childatt->attinhcount == 1 && !childatt->attislocal) { /* Time to delete this child column, too */ ATExecDropColumn(wqueue, childrel, colName, behavior, true, true, false, lockmode, addrs); } else { /* Child column must survive my deletion */ childatt->attinhcount--; CatalogTupleUpdate(attr_rel, &tuple->t_self, tuple); /* Make update visible */ CommandCounterIncrement(); } } else { /* * If we were told to drop ONLY in this table (no recursion), * we need to mark the inheritors' attributes as locally * defined rather than inherited. */ childatt->attinhcount--; childatt->attislocal = true; CatalogTupleUpdate(attr_rel, &tuple->t_self, tuple); /* Make update visible */ CommandCounterIncrement(); } heap_freetuple(tuple); table_close(childrel, NoLock); } table_close(attr_rel, RowExclusiveLock); } /* Add object to delete */ object.classId = RelationRelationId; object.objectId = RelationGetRelid(rel); object.objectSubId = attnum; add_exact_object_address(&object, addrs); if (!recursing) { /* Recursion has ended, drop everything that was collected */ performMultipleDeletions(addrs, behavior, 0); free_object_addresses(addrs); } return object; } /* * Prepare to add a primary key on a table, by adding not-null constraints * on all columns. * * The not-null constraints for a primary key must cover the whole inheritance * hierarchy (failing to ensure that leads to funny corner cases). For the * normal case where we're asked to recurse, this routine checks if the * not-null constraints exist already, and if not queues a requirement for * them to be created by phase 2. * * For the case where we're asked not to recurse, we verify that a not-null * constraint exists on each column of each (direct) child table, throwing an * error if not. Not throwing an error would also work, because a not-null * constraint would be created anyway, but it'd cause a silent scan of the * child table to verify absence of nulls. We prefer to let the user know so * that they can add the constraint manually without having to hold * AccessExclusiveLock while at it. * * However, it's also important that we do not acquire locks on children if * the not-null constraints already exist on the parent, to avoid risking * deadlocks during parallel pg_restore of PKs on partitioned tables. */ static void ATPrepAddPrimaryKey(List **wqueue, Relation rel, AlterTableCmd *cmd, bool recurse, LOCKMODE lockmode, AlterTableUtilityContext *context) { Constraint *pkconstr; List *children = NIL; bool got_children = false; pkconstr = castNode(Constraint, cmd->def); if (pkconstr->contype != CONSTR_PRIMARY) return; /* Verify that columns are not-null, or request that they be made so */ foreach_node(String, column, pkconstr->keys) { AlterTableCmd *newcmd; Constraint *nnconstr; HeapTuple tuple; /* * First check if a suitable constraint exists. If it does, we don't * need to request another one. We do need to bail out if it's not * valid, though. */ tuple = findNotNullConstraint(RelationGetRelid(rel), strVal(column)); if (tuple != NULL) { verifyNotNullPKCompatible(tuple, strVal(column)); /* All good with this one; don't request another */ heap_freetuple(tuple); continue; } else if (!recurse) { /* * No constraint on this column. Asked not to recurse, we won't * create one here, but verify that all children have one. */ if (!got_children) { children = find_inheritance_children(RelationGetRelid(rel), lockmode); /* only search for children on the first time through */ got_children = true; } foreach_oid(childrelid, children) { HeapTuple tup; tup = findNotNullConstraint(childrelid, strVal(column)); if (!tup) ereport(ERROR, errmsg("column \"%s\" of table \"%s\" is not marked NOT NULL", strVal(column), get_rel_name(childrelid))); /* verify it's good enough */ verifyNotNullPKCompatible(tup, strVal(column)); } } /* This column is not already not-null, so add it to the queue */ nnconstr = makeNotNullConstraint(column); newcmd = makeNode(AlterTableCmd); newcmd->subtype = AT_AddConstraint; /* note we force recurse=true here; see above */ newcmd->recurse = true; newcmd->def = (Node *) nnconstr; ATPrepCmd(wqueue, rel, newcmd, true, false, lockmode, context); } } /* * Verify whether the given not-null constraint is compatible with a * primary key. If not, an error is thrown. */ static void verifyNotNullPKCompatible(HeapTuple tuple, const char *colname) { Form_pg_constraint conForm = (Form_pg_constraint) GETSTRUCT(tuple); if (conForm->contype != CONSTRAINT_NOTNULL) elog(ERROR, "constraint %u is not a not-null constraint", conForm->oid); /* a NO INHERIT constraint is no good */ if (conForm->connoinherit) ereport(ERROR, errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("cannot create primary key on column \"%s\"", colname), /*- translator: fourth %s is a constraint characteristic such as NOT VALID */ errdetail("The constraint \"%s\" on column \"%s\" of table \"%s\", marked %s, is incompatible with a primary key.", NameStr(conForm->conname), colname, get_rel_name(conForm->conrelid), "NO INHERIT"), errhint("You might need to make the existing constraint inheritable using %s.", "ALTER TABLE ... ALTER CONSTRAINT ... INHERIT")); /* an unvalidated constraint is no good */ if (!conForm->convalidated) ereport(ERROR, errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("cannot create primary key on column \"%s\"", colname), /*- translator: fourth %s is a constraint characteristic such as NOT VALID */ errdetail("The constraint \"%s\" on column \"%s\" of table \"%s\", marked %s, is incompatible with a primary key.", NameStr(conForm->conname), colname, get_rel_name(conForm->conrelid), "NOT VALID"), errhint("You might need to validate it using %s.", "ALTER TABLE ... VALIDATE CONSTRAINT")); } /* * ALTER TABLE ADD INDEX * * There is no such command in the grammar, but parse_utilcmd.c converts * UNIQUE and PRIMARY KEY constraints into AT_AddIndex subcommands. This lets * us schedule creation of the index at the appropriate time during ALTER. * * Return value is the address of the new index. */ static ObjectAddress ATExecAddIndex(AlteredTableInfo *tab, Relation rel, IndexStmt *stmt, bool is_rebuild, LOCKMODE lockmode) { bool check_rights; bool skip_build; bool quiet; ObjectAddress address; Assert(IsA(stmt, IndexStmt)); Assert(!stmt->concurrent); /* The IndexStmt has already been through transformIndexStmt */ Assert(stmt->transformed); /* suppress schema rights check when rebuilding existing index */ check_rights = !is_rebuild; /* skip index build if phase 3 will do it or we're reusing an old one */ skip_build = tab->rewrite > 0 || RelFileNumberIsValid(stmt->oldNumber); /* suppress notices when rebuilding existing index */ quiet = is_rebuild; address = DefineIndex(NULL, RelationGetRelid(rel), stmt, InvalidOid, /* no predefined OID */ InvalidOid, /* no parent index */ InvalidOid, /* no parent constraint */ -1, /* total_parts unknown */ true, /* is_alter_table */ check_rights, false, /* check_not_in_use - we did it already */ skip_build, quiet); /* * If TryReuseIndex() stashed a relfilenumber for us, we used it for the * new index instead of building from scratch. Restore associated fields. * This may store InvalidSubTransactionId in both fields, in which case * relcache.c will assume it can rebuild the relcache entry. Hence, do * this after the CCI that made catalog rows visible to any rebuild. The * DROP of the old edition of this index will have scheduled the storage * for deletion at commit, so cancel that pending deletion. */ if (RelFileNumberIsValid(stmt->oldNumber)) { Relation irel = index_open(address.objectId, NoLock); irel->rd_createSubid = stmt->oldCreateSubid; irel->rd_firstRelfilelocatorSubid = stmt->oldFirstRelfilelocatorSubid; RelationPreserveStorage(irel->rd_locator, true); index_close(irel, NoLock); } return address; } /* * ALTER TABLE ADD STATISTICS * * This is no such command in the grammar, but we use this internally to add * AT_ReAddStatistics subcommands to rebuild extended statistics after a table * column type change. */ static ObjectAddress ATExecAddStatistics(AlteredTableInfo *tab, Relation rel, CreateStatsStmt *stmt, bool is_rebuild, LOCKMODE lockmode) { ObjectAddress address; Assert(IsA(stmt, CreateStatsStmt)); /* The CreateStatsStmt has already been through transformStatsStmt */ Assert(stmt->transformed); /* The owner must be set to the original statistics owner */ Assert(OidIsValid(stmt->owner)); address = CreateStatistics(list_make1_oid(RelationGetRelid(rel)), stmt, !is_rebuild); return address; } /* * ALTER TABLE ADD CONSTRAINT USING INDEX * * Returns the address of the new constraint. */ static ObjectAddress ATExecAddIndexConstraint(AlteredTableInfo *tab, Relation rel, IndexStmt *stmt, LOCKMODE lockmode) { Oid index_oid = stmt->indexOid; Relation indexRel; char *indexName; IndexInfo *indexInfo; char *constraintName; char constraintType; ObjectAddress address; uint16 flags; Assert(IsA(stmt, IndexStmt)); Assert(OidIsValid(index_oid)); Assert(stmt->isconstraint); /* * Doing this on partitioned tables is not a simple feature to implement, * so let's punt for now. */ if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("ALTER TABLE / ADD CONSTRAINT USING INDEX is not supported on partitioned tables"))); indexRel = index_open(index_oid, AccessShareLock); indexName = pstrdup(RelationGetRelationName(indexRel)); indexInfo = BuildIndexInfo(indexRel); /* this should have been checked at parse time */ if (!indexInfo->ii_Unique) elog(ERROR, "index \"%s\" is not unique", indexName); /* * Determine name to assign to constraint. We require a constraint to * have the same name as the underlying index; therefore, use the index's * existing name as the default constraint name, and if the user * explicitly gives some other name for the constraint, rename the index * to match. */ constraintName = stmt->idxname; if (constraintName == NULL) constraintName = indexName; else if (strcmp(constraintName, indexName) != 0) { ereport(NOTICE, (errmsg("ALTER TABLE / ADD CONSTRAINT USING INDEX will rename index \"%s\" to \"%s\"", indexName, constraintName))); RenameRelationInternal(index_oid, constraintName, false, true); } /* Extra checks needed if making primary key */ if (stmt->primary) index_check_primary_key(rel, indexInfo, true, stmt); /* Note we currently don't support EXCLUSION constraints here */ if (stmt->primary) constraintType = CONSTRAINT_PRIMARY; else constraintType = CONSTRAINT_UNIQUE; /* Create the catalog entries for the constraint */ flags = INDEX_CONSTR_CREATE_UPDATE_INDEX | INDEX_CONSTR_CREATE_REMOVE_OLD_DEPS | (stmt->initdeferred ? INDEX_CONSTR_CREATE_INIT_DEFERRED : 0) | (stmt->deferrable ? INDEX_CONSTR_CREATE_DEFERRABLE : 0) | (stmt->primary ? INDEX_CONSTR_CREATE_MARK_AS_PRIMARY : 0); address = index_constraint_create(rel, index_oid, InvalidOid, indexInfo, constraintName, constraintType, flags, allowSystemTableMods, false); /* is_internal */ index_close(indexRel, NoLock); return address; } /* * ALTER TABLE ADD CONSTRAINT * * Return value is the address of the new constraint; if no constraint was * added, InvalidObjectAddress is returned. */ static ObjectAddress ATExecAddConstraint(List **wqueue, AlteredTableInfo *tab, Relation rel, Constraint *newConstraint, bool recurse, bool is_readd, LOCKMODE lockmode) { ObjectAddress address = InvalidObjectAddress; Assert(IsA(newConstraint, Constraint)); /* * Currently, we only expect to see CONSTR_CHECK, CONSTR_NOTNULL and * CONSTR_FOREIGN nodes arriving here (see the preprocessing done in * parse_utilcmd.c). */ switch (newConstraint->contype) { case CONSTR_CHECK: case CONSTR_NOTNULL: address = ATAddCheckNNConstraint(wqueue, tab, rel, newConstraint, recurse, false, is_readd, lockmode); break; case CONSTR_FOREIGN: /* * Assign or validate constraint name */ if (newConstraint->conname) { if (ConstraintNameIsUsed(CONSTRAINT_RELATION, RelationGetRelid(rel), newConstraint->conname)) ereport(ERROR, (errcode(ERRCODE_DUPLICATE_OBJECT), errmsg("constraint \"%s\" for relation \"%s\" already exists", newConstraint->conname, RelationGetRelationName(rel)))); } else newConstraint->conname = ChooseConstraintName(RelationGetRelationName(rel), ChooseForeignKeyConstraintNameAddition(newConstraint->fk_attrs), "fkey", RelationGetNamespace(rel), NIL); address = ATAddForeignKeyConstraint(wqueue, tab, rel, newConstraint, recurse, false, lockmode); break; default: elog(ERROR, "unrecognized constraint type: %d", (int) newConstraint->contype); } return address; } /* * Generate the column-name portion of the constraint name for a new foreign * key given the list of column names that reference the referenced * table. This will be passed to ChooseConstraintName along with the parent * table name and the "fkey" suffix. * * We know that less than NAMEDATALEN characters will actually be used, so we * can truncate the result once we've generated that many. * * XXX see also ChooseExtendedStatisticNameAddition and * ChooseIndexNameAddition. */ static char * ChooseForeignKeyConstraintNameAddition(List *colnames) { char buf[NAMEDATALEN * 2]; int buflen = 0; ListCell *lc; buf[0] = '\0'; foreach(lc, colnames) { const char *name = strVal(lfirst(lc)); if (buflen > 0) buf[buflen++] = '_'; /* insert _ between names */ /* * At this point we have buflen <= NAMEDATALEN. name should be less * than NAMEDATALEN already, but use strlcpy for paranoia. */ strlcpy(buf + buflen, name, NAMEDATALEN); buflen += strlen(buf + buflen); if (buflen >= NAMEDATALEN) break; } return pstrdup(buf); } /* * Add a check or not-null constraint to a single table and its children. * Returns the address of the constraint added to the parent relation, * if one gets added, or InvalidObjectAddress otherwise. * * Subroutine for ATExecAddConstraint. * * We must recurse to child tables during execution, rather than using * ALTER TABLE's normal prep-time recursion. The reason is that all the * constraints *must* be given the same name, else they won't be seen as * related later. If the user didn't explicitly specify a name, then * AddRelationNewConstraints would normally assign different names to the * child constraints. To fix that, we must capture the name assigned at * the parent table and pass that down. */ static ObjectAddress ATAddCheckNNConstraint(List **wqueue, AlteredTableInfo *tab, Relation rel, Constraint *constr, bool recurse, bool recursing, bool is_readd, LOCKMODE lockmode) { List *newcons; ListCell *lcon; List *children; ListCell *child; ObjectAddress address = InvalidObjectAddress; /* Guard against stack overflow due to overly deep inheritance tree. */ check_stack_depth(); /* At top level, permission check was done in ATPrepCmd, else do it */ if (recursing) ATSimplePermissions(AT_AddConstraint, rel, ATT_TABLE | ATT_PARTITIONED_TABLE | ATT_FOREIGN_TABLE); /* * Call AddRelationNewConstraints to do the work, making sure it works on * a copy of the Constraint so transformExpr can't modify the original. It * returns a list of cooked constraints. * * If the constraint ends up getting merged with a pre-existing one, it's * omitted from the returned list, which is what we want: we do not need * to do any validation work. That can only happen at child tables, * though, since we disallow merging at the top level. */ newcons = AddRelationNewConstraints(rel, NIL, list_make1(copyObject(constr)), recursing || is_readd, /* allow_merge */ !recursing, /* is_local */ is_readd, /* is_internal */ NULL); /* queryString not available * here */ /* we don't expect more than one constraint here */ Assert(list_length(newcons) <= 1); /* Add each to-be-validated constraint to Phase 3's queue */ foreach(lcon, newcons) { CookedConstraint *ccon = (CookedConstraint *) lfirst(lcon); if (!ccon->skip_validation && ccon->contype != CONSTR_NOTNULL) { NewConstraint *newcon; newcon = palloc0_object(NewConstraint); newcon->name = ccon->name; newcon->contype = ccon->contype; newcon->qual = ccon->expr; tab->constraints = lappend(tab->constraints, newcon); } /* Save the actually assigned name if it was defaulted */ if (constr->conname == NULL) constr->conname = ccon->name; /* * If adding a valid not-null constraint, set the pg_attribute flag * and tell phase 3 to verify existing rows, if needed. For an * invalid constraint, just set attnotnull, without queueing * verification. */ if (constr->contype == CONSTR_NOTNULL) set_attnotnull(wqueue, rel, ccon->attnum, !constr->skip_validation); ObjectAddressSet(address, ConstraintRelationId, ccon->conoid); } /* At this point we must have a locked-down name to use */ Assert(newcons == NIL || constr->conname != NULL); /* Advance command counter in case same table is visited multiple times */ CommandCounterIncrement(); /* * If the constraint got merged with an existing constraint, we're done. * We mustn't recurse to child tables in this case, because they've * already got the constraint, and visiting them again would lead to an * incorrect value for coninhcount. */ if (newcons == NIL) return address; /* * If adding a NO INHERIT constraint, no need to find our children. */ if (constr->is_no_inherit) return address; /* * Propagate to children as appropriate. Unlike most other ALTER * routines, we have to do this one level of recursion at a time; we can't * use find_all_inheritors to do it in one pass. */ children = find_inheritance_children(RelationGetRelid(rel), lockmode); /* * Check if ONLY was specified with ALTER TABLE. If so, allow the * constraint creation only if there are no children currently. Error out * otherwise. */ if (!recurse && children != NIL) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("constraint must be added to child tables too"))); /* * Recurse to create the constraint on each child. */ foreach(child, children) { Oid childrelid = lfirst_oid(child); Relation childrel; AlteredTableInfo *childtab; /* find_inheritance_children already got lock */ childrel = table_open(childrelid, NoLock); CheckAlterTableIsSafe(childrel); /* Find or create work queue entry for this table */ childtab = ATGetQueueEntry(wqueue, childrel); /* Recurse to this child */ ATAddCheckNNConstraint(wqueue, childtab, childrel, constr, recurse, true, is_readd, lockmode); table_close(childrel, NoLock); } return address; } /* * Add a foreign-key constraint to a single table; return the new constraint's * address. * * Subroutine for ATExecAddConstraint. Must already hold exclusive * lock on the rel, and have done appropriate validity checks for it. * We do permissions checks here, however. * * When the referenced or referencing tables (or both) are partitioned, * multiple pg_constraint rows are required -- one for each partitioned table * and each partition on each side (fortunately, not one for every combination * thereof). We also need action triggers on each leaf partition on the * referenced side, and check triggers on each leaf partition on the * referencing side. */ static ObjectAddress ATAddForeignKeyConstraint(List **wqueue, AlteredTableInfo *tab, Relation rel, Constraint *fkconstraint, bool recurse, bool recursing, LOCKMODE lockmode) { Relation pkrel; int16 pkattnum[INDEX_MAX_KEYS] = {0}; int16 fkattnum[INDEX_MAX_KEYS] = {0}; Oid pktypoid[INDEX_MAX_KEYS] = {0}; Oid fktypoid[INDEX_MAX_KEYS] = {0}; Oid pkcolloid[INDEX_MAX_KEYS] = {0}; Oid fkcolloid[INDEX_MAX_KEYS] = {0}; Oid opclasses[INDEX_MAX_KEYS] = {0}; Oid pfeqoperators[INDEX_MAX_KEYS] = {0}; Oid ppeqoperators[INDEX_MAX_KEYS] = {0}; Oid ffeqoperators[INDEX_MAX_KEYS] = {0}; int16 fkdelsetcols[INDEX_MAX_KEYS] = {0}; bool with_period; bool pk_has_without_overlaps; int i; int numfks, numpks, numfkdelsetcols; Oid indexOid; bool old_check_ok; ObjectAddress address; ListCell *old_pfeqop_item = list_head(fkconstraint->old_conpfeqop); /* * Grab ShareRowExclusiveLock on the pk table, so that someone doesn't * delete rows out from under us. */ if (OidIsValid(fkconstraint->old_pktable_oid)) pkrel = table_open(fkconstraint->old_pktable_oid, ShareRowExclusiveLock); else pkrel = table_openrv(fkconstraint->pktable, ShareRowExclusiveLock); /* * Validity checks (permission checks wait till we have the column * numbers) */ if (!recurse && rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) ereport(ERROR, errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot use ONLY for foreign key on partitioned table \"%s\" referencing relation \"%s\"", RelationGetRelationName(rel), RelationGetRelationName(pkrel))); if (pkrel->rd_rel->relkind != RELKIND_RELATION && pkrel->rd_rel->relkind != RELKIND_PARTITIONED_TABLE) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("referenced relation \"%s\" is not a table", RelationGetRelationName(pkrel)))); /* * Conflict log tables are used internally for logical replication * conflict logging and should not be referenced by foreign keys, as it * could disrupt conflict logging. */ if (IsConflictLogTableClass(pkrel->rd_rel)) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot reference conflict log table \"%s\"", RelationGetRelationName(pkrel)), errdetail("Conflict log tables are system-managed tables for logical replication conflicts."))); if (!allowSystemTableMods && IsSystemRelation(pkrel)) ereport(ERROR, (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), errmsg("permission denied: \"%s\" is a system catalog", RelationGetRelationName(pkrel)))); /* * References from permanent or unlogged tables to temp tables, and from * permanent tables to unlogged tables, are disallowed because the * referenced data can vanish out from under us. References from temp * tables to any other table type are also disallowed, because other * backends might need to run the RI triggers on the perm table, but they * can't reliably see tuples in the local buffers of other backends. */ switch (rel->rd_rel->relpersistence) { case RELPERSISTENCE_PERMANENT: if (!RelationIsPermanent(pkrel)) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("constraints on permanent tables may reference only permanent tables"))); break; case RELPERSISTENCE_UNLOGGED: if (!RelationIsPermanent(pkrel) && pkrel->rd_rel->relpersistence != RELPERSISTENCE_UNLOGGED) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("constraints on unlogged tables may reference only permanent or unlogged tables"))); break; case RELPERSISTENCE_TEMP: if (pkrel->rd_rel->relpersistence != RELPERSISTENCE_TEMP) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("constraints on temporary tables may reference only temporary tables"))); if (!pkrel->rd_islocaltemp || !rel->rd_islocaltemp) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("constraints on temporary tables must involve temporary tables of this session"))); break; } /* * Look up the referencing attributes to make sure they exist, and record * their attnums and type and collation OIDs. */ numfks = transformColumnNameList(RelationGetRelid(rel), fkconstraint->fk_attrs, fkattnum, fktypoid, fkcolloid); with_period = fkconstraint->fk_with_period || fkconstraint->pk_with_period; if (with_period && !fkconstraint->fk_with_period) ereport(ERROR, errcode(ERRCODE_INVALID_FOREIGN_KEY), errmsg("foreign key uses PERIOD on the referenced table but not the referencing table")); numfkdelsetcols = transformColumnNameList(RelationGetRelid(rel), fkconstraint->fk_del_set_cols, fkdelsetcols, NULL, NULL); numfkdelsetcols = validateFkOnDeleteSetColumns(numfks, fkattnum, numfkdelsetcols, fkdelsetcols, fkconstraint->fk_del_set_cols); /* * If the attribute list for the referenced table was omitted, lookup the * definition of the primary key and use it. Otherwise, validate the * supplied attribute list. In either case, discover the index OID and * index opclasses, and the attnums and type and collation OIDs of the * attributes. */ if (fkconstraint->pk_attrs == NIL) { numpks = transformFkeyGetPrimaryKey(pkrel, &indexOid, &fkconstraint->pk_attrs, pkattnum, pktypoid, pkcolloid, opclasses, &pk_has_without_overlaps); /* If the primary key uses WITHOUT OVERLAPS, the fk must use PERIOD */ if (pk_has_without_overlaps && !fkconstraint->fk_with_period) ereport(ERROR, errcode(ERRCODE_INVALID_FOREIGN_KEY), errmsg("foreign key uses PERIOD on the referenced table but not the referencing table")); } else { numpks = transformColumnNameList(RelationGetRelid(pkrel), fkconstraint->pk_attrs, pkattnum, pktypoid, pkcolloid); /* Since we got pk_attrs, one should be a period. */ if (with_period && !fkconstraint->pk_with_period) ereport(ERROR, errcode(ERRCODE_INVALID_FOREIGN_KEY), errmsg("foreign key uses PERIOD on the referencing table but not the referenced table")); /* Look for an index matching the column list */ indexOid = transformFkeyCheckAttrs(pkrel, numpks, pkattnum, with_period, opclasses, &pk_has_without_overlaps); } /* * If the referenced primary key has WITHOUT OVERLAPS, the foreign key * must use PERIOD. */ if (pk_has_without_overlaps && !with_period) ereport(ERROR, errcode(ERRCODE_INVALID_FOREIGN_KEY), errmsg("foreign key must use PERIOD when referencing a primary key using WITHOUT OVERLAPS")); /* * Now we can check permissions. */ checkFkeyPermissions(pkrel, pkattnum, numpks); /* * Check some things for generated columns. */ for (i = 0; i < numfks; i++) { char attgenerated = TupleDescAttr(RelationGetDescr(rel), fkattnum[i] - 1)->attgenerated; if (attgenerated) { /* * Check restrictions on UPDATE/DELETE actions, per SQL standard */ if (fkconstraint->fk_upd_action == FKCONSTR_ACTION_SETNULL || fkconstraint->fk_upd_action == FKCONSTR_ACTION_SETDEFAULT || fkconstraint->fk_upd_action == FKCONSTR_ACTION_CASCADE) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("invalid %s action for foreign key constraint containing generated column", "ON UPDATE"))); if (fkconstraint->fk_del_action == FKCONSTR_ACTION_SETNULL || fkconstraint->fk_del_action == FKCONSTR_ACTION_SETDEFAULT) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("invalid %s action for foreign key constraint containing generated column", "ON DELETE"))); } /* * FKs on virtual columns are not supported. This would require * various additional support in ri_triggers.c, including special * handling in ri_NullCheck(), ri_KeysEqual(), * RI_FKey_fk_upd_check_required() (since all virtual columns appear * as NULL there). Also not really practical as long as you can't * index virtual columns. */ if (attgenerated == ATTRIBUTE_GENERATED_VIRTUAL) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("foreign key constraints on virtual generated columns are not supported"))); } /* * Some actions are currently unsupported for foreign keys using PERIOD. */ if (fkconstraint->fk_with_period) { if (fkconstraint->fk_upd_action == FKCONSTR_ACTION_RESTRICT || fkconstraint->fk_upd_action == FKCONSTR_ACTION_CASCADE || fkconstraint->fk_upd_action == FKCONSTR_ACTION_SETNULL || fkconstraint->fk_upd_action == FKCONSTR_ACTION_SETDEFAULT) ereport(ERROR, errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("unsupported %s action for foreign key constraint using PERIOD", "ON UPDATE")); if (fkconstraint->fk_del_action == FKCONSTR_ACTION_RESTRICT || fkconstraint->fk_del_action == FKCONSTR_ACTION_CASCADE || fkconstraint->fk_del_action == FKCONSTR_ACTION_SETNULL || fkconstraint->fk_del_action == FKCONSTR_ACTION_SETDEFAULT) ereport(ERROR, errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("unsupported %s action for foreign key constraint using PERIOD", "ON DELETE")); } /* * Look up the equality operators to use in the constraint. * * Note that we have to be careful about the difference between the actual * PK column type and the opclass' declared input type, which might be * only binary-compatible with it. The declared opcintype is the right * thing to probe pg_amop with. */ if (numfks != numpks) ereport(ERROR, (errcode(ERRCODE_INVALID_FOREIGN_KEY), errmsg("number of referencing and referenced columns for foreign key disagree"))); /* * On the strength of a previous constraint, we might avoid scanning * tables to validate this one. See below. */ old_check_ok = (fkconstraint->old_conpfeqop != NIL); Assert(!old_check_ok || numfks == list_length(fkconstraint->old_conpfeqop)); for (i = 0; i < numpks; i++) { Oid pktype = pktypoid[i]; Oid fktype = fktypoid[i]; Oid fktyped; Oid pkcoll = pkcolloid[i]; Oid fkcoll = fkcolloid[i]; HeapTuple cla_ht; Form_pg_opclass cla_tup; Oid amid; Oid opfamily; Oid opcintype; bool for_overlaps; CompareType cmptype; Oid pfeqop; Oid ppeqop; Oid ffeqop; int16 eqstrategy; Oid pfeqop_right; /* We need several fields out of the pg_opclass entry */ cla_ht = SearchSysCache1(CLAOID, ObjectIdGetDatum(opclasses[i])); if (!HeapTupleIsValid(cla_ht)) elog(ERROR, "cache lookup failed for opclass %u", opclasses[i]); cla_tup = (Form_pg_opclass) GETSTRUCT(cla_ht); amid = cla_tup->opcmethod; opfamily = cla_tup->opcfamily; opcintype = cla_tup->opcintype; ReleaseSysCache(cla_ht); /* * Get strategy number from index AM. * * For a normal foreign-key constraint, this should not fail, since we * already checked that the index is unique and should therefore have * appropriate equal operators. For a period foreign key, this could * fail if we selected a non-matching exclusion constraint earlier. * (XXX Maybe we should do these lookups earlier so we don't end up * doing that.) */ for_overlaps = with_period && i == numpks - 1; cmptype = for_overlaps ? COMPARE_OVERLAP : COMPARE_EQ; eqstrategy = IndexAmTranslateCompareType(cmptype, amid, opfamily, true); if (eqstrategy == InvalidStrategy) ereport(ERROR, errcode(ERRCODE_UNDEFINED_OBJECT), for_overlaps ? errmsg("could not identify an overlaps operator for foreign key") : errmsg("could not identify an equality operator for foreign key"), errdetail("Could not translate compare type %d for operator family \"%s\" of access method \"%s\".", cmptype, get_opfamily_name(opfamily, false), get_am_name(amid))); /* * There had better be a primary equality operator for the index. * We'll use it for PK = PK comparisons. */ ppeqop = get_opfamily_member(opfamily, opcintype, opcintype, eqstrategy); if (!OidIsValid(ppeqop)) elog(ERROR, "missing operator %d(%u,%u) in opfamily %u", eqstrategy, opcintype, opcintype, opfamily); /* * Are there equality operators that take exactly the FK type? Assume * we should look through any domain here. */ fktyped = getBaseType(fktype); pfeqop = get_opfamily_member(opfamily, opcintype, fktyped, eqstrategy); if (OidIsValid(pfeqop)) { pfeqop_right = fktyped; ffeqop = get_opfamily_member(opfamily, fktyped, fktyped, eqstrategy); } else { /* keep compiler quiet */ pfeqop_right = InvalidOid; ffeqop = InvalidOid; } if (!(OidIsValid(pfeqop) && OidIsValid(ffeqop))) { /* * Otherwise, look for an implicit cast from the FK type to the * opcintype, and if found, use the primary equality operator. * This is a bit tricky because opcintype might be a polymorphic * type such as ANYARRAY or ANYENUM; so what we have to test is * whether the two actual column types can be concurrently cast to * that type. (Otherwise, we'd fail to reject combinations such * as int[] and point[].) */ Oid input_typeids[2]; Oid target_typeids[2]; input_typeids[0] = pktype; input_typeids[1] = fktype; target_typeids[0] = opcintype; target_typeids[1] = opcintype; if (can_coerce_type(2, input_typeids, target_typeids, COERCION_IMPLICIT)) { pfeqop = ffeqop = ppeqop; pfeqop_right = opcintype; } } if (!(OidIsValid(pfeqop) && OidIsValid(ffeqop))) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("foreign key constraint \"%s\" cannot be implemented", fkconstraint->conname), errdetail("Key columns \"%s\" of the referencing table and \"%s\" of the referenced table " "are of incompatible types: %s and %s.", strVal(list_nth(fkconstraint->fk_attrs, i)), strVal(list_nth(fkconstraint->pk_attrs, i)), format_type_be(fktype), format_type_be(pktype)))); /* * This shouldn't be possible, but better check to make sure we have a * consistent state for the check below. */ if ((OidIsValid(pkcoll) && !OidIsValid(fkcoll)) || (!OidIsValid(pkcoll) && OidIsValid(fkcoll))) elog(ERROR, "key columns are not both collatable"); if (OidIsValid(pkcoll) && OidIsValid(fkcoll)) { bool pkcolldet; bool fkcolldet; pkcolldet = get_collation_isdeterministic(pkcoll); fkcolldet = get_collation_isdeterministic(fkcoll); /* * SQL requires that both collations are the same. This is * because we need a consistent notion of equality on both * columns. We relax this by allowing different collations if * they are both deterministic. (This is also for backward * compatibility, because PostgreSQL has always allowed this.) */ if ((!pkcolldet || !fkcolldet) && pkcoll != fkcoll) ereport(ERROR, (errcode(ERRCODE_COLLATION_MISMATCH), errmsg("foreign key constraint \"%s\" cannot be implemented", fkconstraint->conname), errdetail("Key columns \"%s\" of the referencing table and \"%s\" of the referenced table " "have incompatible collations: \"%s\" and \"%s\". " "If either collation is nondeterministic, then both collations have to be the same.", strVal(list_nth(fkconstraint->fk_attrs, i)), strVal(list_nth(fkconstraint->pk_attrs, i)), get_collation_name(fkcoll), get_collation_name(pkcoll)))); } if (old_check_ok) { /* * When a pfeqop changes, revalidate the constraint. We could * permit intra-opfamily changes, but that adds subtle complexity * without any concrete benefit for core types. We need not * assess ppeqop or ffeqop, which RI_Initial_Check() does not use. */ old_check_ok = (pfeqop == lfirst_oid(old_pfeqop_item)); old_pfeqop_item = lnext(fkconstraint->old_conpfeqop, old_pfeqop_item); } if (old_check_ok) { Oid old_fktype; Oid new_fktype; CoercionPathType old_pathtype; CoercionPathType new_pathtype; Oid old_castfunc; Oid new_castfunc; Oid old_fkcoll; Oid new_fkcoll; Form_pg_attribute attr = TupleDescAttr(tab->oldDesc, fkattnum[i] - 1); /* * Identify coercion pathways from each of the old and new FK-side * column types to the right (foreign) operand type of the pfeqop. * We may assume that pg_constraint.conkey is not changing. */ old_fktype = attr->atttypid; new_fktype = fktype; old_pathtype = findFkeyCast(pfeqop_right, old_fktype, &old_castfunc); new_pathtype = findFkeyCast(pfeqop_right, new_fktype, &new_castfunc); old_fkcoll = attr->attcollation; new_fkcoll = fkcoll; /* * Upon a change to the cast from the FK column to its pfeqop * operand, revalidate the constraint. For this evaluation, a * binary coercion cast is equivalent to no cast at all. While * type implementors should design implicit casts with an eye * toward consistency of operations like equality, we cannot * assume here that they have done so. * * A function with a polymorphic argument could change behavior * arbitrarily in response to get_fn_expr_argtype(). Therefore, * when the cast destination is polymorphic, we only avoid * revalidation if the input type has not changed at all. Given * just the core data types and operator classes, this requirement * prevents no would-be optimizations. * * If the cast converts from a base type to a domain thereon, then * that domain type must be the opcintype of the unique index. * Necessarily, the primary key column must then be of the domain * type. Since the constraint was previously valid, all values on * the foreign side necessarily exist on the primary side and in * turn conform to the domain. Consequently, we need not treat * domains specially here. * * If the collation changes, revalidation is required, unless both * collations are deterministic, because those share the same * notion of equality (because texteq reduces to bitwise * equality). * * We need not directly consider the PK type. It's necessarily * binary coercible to the opcintype of the unique index column, * and ri_triggers.c will only deal with PK datums in terms of * that opcintype. Changing the opcintype also changes pfeqop. */ old_check_ok = (new_pathtype == old_pathtype && new_castfunc == old_castfunc && (!IsPolymorphicType(pfeqop_right) || new_fktype == old_fktype) && (new_fkcoll == old_fkcoll || (get_collation_isdeterministic(old_fkcoll) && get_collation_isdeterministic(new_fkcoll)))); } pfeqoperators[i] = pfeqop; ppeqoperators[i] = ppeqop; ffeqoperators[i] = ffeqop; } /* * For FKs with PERIOD we need additional operators to check whether the * referencing row's range is contained by the aggregated ranges of the * referenced row(s). For rangetypes and multirangetypes this is * fk.periodatt <@ range_agg(pk.periodatt). Those are the only types we * support for now. FKs will look these up at "runtime", but we should * make sure the lookup works here, even if we don't use the values. */ if (with_period) { Oid periodoperoid; Oid aggedperiodoperoid; Oid intersectoperoid; FindFKPeriodOpers(opclasses[numpks - 1], &periodoperoid, &aggedperiodoperoid, &intersectoperoid); } /* First, create the constraint catalog entry itself. */ address = addFkConstraint(addFkBothSides, fkconstraint->conname, fkconstraint, rel, pkrel, indexOid, InvalidOid, /* no parent constraint */ numfks, pkattnum, fkattnum, pfeqoperators, ppeqoperators, ffeqoperators, numfkdelsetcols, fkdelsetcols, false, with_period); /* Next process the action triggers at the referenced side and recurse */ addFkRecurseReferenced(fkconstraint, rel, pkrel, indexOid, address.objectId, numfks, pkattnum, fkattnum, pfeqoperators, ppeqoperators, ffeqoperators, numfkdelsetcols, fkdelsetcols, old_check_ok, InvalidOid, InvalidOid, with_period); /* Lastly create the check triggers at the referencing side and recurse */ addFkRecurseReferencing(wqueue, fkconstraint, rel, pkrel, indexOid, address.objectId, numfks, pkattnum, fkattnum, pfeqoperators, ppeqoperators, ffeqoperators, numfkdelsetcols, fkdelsetcols, old_check_ok, lockmode, InvalidOid, InvalidOid, with_period); /* * Done. Close pk table, but keep lock until we've committed. */ table_close(pkrel, NoLock); return address; } /* * validateFkOnDeleteSetColumns * Verifies that columns used in ON DELETE SET NULL/DEFAULT (...) * column lists are valid. * * If there are duplicates in the fksetcolsattnums[] array, this silently * removes the dups. The new count of numfksetcols is returned. */ static int validateFkOnDeleteSetColumns(int numfks, const int16 *fkattnums, int numfksetcols, int16 *fksetcolsattnums, List *fksetcols) { int numcolsout = 0; for (int i = 0; i < numfksetcols; i++) { int16 setcol_attnum = fksetcolsattnums[i]; bool seen = false; /* Make sure it's in fkattnums[] */ for (int j = 0; j < numfks; j++) { if (fkattnums[j] == setcol_attnum) { seen = true; break; } } if (!seen) { char *col = strVal(list_nth(fksetcols, i)); ereport(ERROR, (errcode(ERRCODE_INVALID_COLUMN_REFERENCE), errmsg("column \"%s\" referenced in ON DELETE SET action must be part of foreign key", col))); } /* Now check for dups */ seen = false; for (int j = 0; j < numcolsout; j++) { if (fksetcolsattnums[j] == setcol_attnum) { seen = true; break; } } if (!seen) fksetcolsattnums[numcolsout++] = setcol_attnum; } return numcolsout; } /* * addFkConstraint * Install pg_constraint entries to implement a foreign key constraint. * Caller must separately invoke addFkRecurseReferenced and * addFkRecurseReferencing, as appropriate, to install pg_trigger entries * and (for partitioned tables) recurse to partitions. * * fkside: the side of the FK (or both) to create. Caller should * call addFkRecurseReferenced if this is addFkReferencedSide, * addFkRecurseReferencing if it's addFkReferencingSide, or both if it's * addFkBothSides. * constraintname: the base name for the constraint being added, * copied to fkconstraint->conname if the latter is not set * fkconstraint: the constraint being added * rel: the root referencing relation * pkrel: the referenced relation; might be a partition, if recursing * indexOid: the OID of the index (on pkrel) implementing this constraint * parentConstr: the OID of a parent constraint; InvalidOid if this is a * top-level constraint * numfks: the number of columns in the foreign key * pkattnum: the attnum array of referenced attributes * fkattnum: the attnum array of referencing attributes * pf/pp/ffeqoperators: OID array of operators between columns * numfkdelsetcols: the number of columns in the ON DELETE SET NULL/DEFAULT * (...) clause * fkdelsetcols: the attnum array of the columns in the ON DELETE SET * NULL/DEFAULT clause * with_period: true if this is a temporal FK */ static ObjectAddress addFkConstraint(addFkConstraintSides fkside, char *constraintname, Constraint *fkconstraint, Relation rel, Relation pkrel, Oid indexOid, Oid parentConstr, int numfks, int16 *pkattnum, int16 *fkattnum, Oid *pfeqoperators, Oid *ppeqoperators, Oid *ffeqoperators, int numfkdelsetcols, int16 *fkdelsetcols, bool is_internal, bool with_period) { ObjectAddress address; Oid constrOid; char *conname; bool conislocal; int16 coninhcount; bool connoinherit; /* * Verify relkind for each referenced partition. At the top level, this * is redundant with a previous check, but we need it when recursing. */ if (pkrel->rd_rel->relkind != RELKIND_RELATION && pkrel->rd_rel->relkind != RELKIND_PARTITIONED_TABLE) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("referenced relation \"%s\" is not a table", RelationGetRelationName(pkrel)))); /* * Caller supplies us with a constraint name; however, it may be used in * this partition, so come up with a different one in that case. Unless * truncation to NAMEDATALEN dictates otherwise, the new name will be the * supplied name with an underscore and digit(s) appended. */ if (ConstraintNameIsUsed(CONSTRAINT_RELATION, RelationGetRelid(rel), constraintname)) conname = ChooseConstraintName(constraintname, NULL, "", RelationGetNamespace(rel), NIL); else conname = constraintname; if (fkconstraint->conname == NULL) fkconstraint->conname = pstrdup(conname); if (OidIsValid(parentConstr)) { conislocal = false; coninhcount = 1; connoinherit = false; } else { conislocal = true; coninhcount = 0; /* * always inherit for partitioned tables, never for legacy inheritance */ connoinherit = rel->rd_rel->relkind != RELKIND_PARTITIONED_TABLE; } /* * Record the FK constraint in pg_constraint. */ constrOid = CreateConstraintEntry(conname, RelationGetNamespace(rel), CONSTRAINT_FOREIGN, fkconstraint->deferrable, fkconstraint->initdeferred, fkconstraint->is_enforced, fkconstraint->initially_valid, parentConstr, RelationGetRelid(rel), fkattnum, numfks, numfks, InvalidOid, /* not a domain constraint */ indexOid, RelationGetRelid(pkrel), pkattnum, pfeqoperators, ppeqoperators, ffeqoperators, numfks, fkconstraint->fk_upd_action, fkconstraint->fk_del_action, fkdelsetcols, numfkdelsetcols, fkconstraint->fk_matchtype, NULL, /* no exclusion constraint */ NULL, /* no check constraint */ NULL, conislocal, /* islocal */ coninhcount, /* inhcount */ connoinherit, /* conNoInherit */ with_period, /* conPeriod */ is_internal); /* is_internal */ ObjectAddressSet(address, ConstraintRelationId, constrOid); /* * In partitioning cases, create the dependency entries for this * constraint. (For non-partitioned cases, relevant entries were created * by CreateConstraintEntry.) * * On the referenced side, we need the constraint to have an internal * dependency on its parent constraint; this means that this constraint * cannot be dropped on its own -- only through the parent constraint. It * also means the containing partition cannot be dropped on its own, but * it can be detached, at which point this dependency is removed (after * verifying that no rows are referenced via this FK.) * * When processing the referencing side, we link the constraint via the * special partitioning dependencies: the parent constraint is the primary * dependent, and the partition on which the foreign key exists is the * secondary dependency. That way, this constraint is dropped if either * of these objects is. * * Note that this is only necessary for the subsidiary pg_constraint rows * in partitions; the topmost row doesn't need any of this. */ if (OidIsValid(parentConstr)) { ObjectAddress referenced; ObjectAddressSet(referenced, ConstraintRelationId, parentConstr); Assert(fkside != addFkBothSides); if (fkside == addFkReferencedSide) recordDependencyOn(&address, &referenced, DEPENDENCY_INTERNAL); else { recordDependencyOn(&address, &referenced, DEPENDENCY_PARTITION_PRI); ObjectAddressSet(referenced, RelationRelationId, RelationGetRelid(rel)); recordDependencyOn(&address, &referenced, DEPENDENCY_PARTITION_SEC); } } /* make new constraint visible, in case we add more */ CommandCounterIncrement(); return address; } /* * addFkRecurseReferenced * Recursive helper for the referenced side of foreign key creation, * which creates the action triggers and recurses * * If the referenced relation is a plain relation, create the necessary action * triggers that implement the constraint. If the referenced relation is a * partitioned table, then we create a pg_constraint row referencing the parent * of the referencing side for it and recurse on this routine for each * partition. * * fkconstraint: the constraint being added * rel: the root referencing relation * pkrel: the referenced relation; might be a partition, if recursing * indexOid: the OID of the index (on pkrel) implementing this constraint * parentConstr: the OID of a parent constraint; InvalidOid if this is a * top-level constraint * numfks: the number of columns in the foreign key * pkattnum: the attnum array of referenced attributes * fkattnum: the attnum array of referencing attributes * numfkdelsetcols: the number of columns in the ON DELETE SET * NULL/DEFAULT (...) clause * fkdelsetcols: the attnum array of the columns in the ON DELETE SET * NULL/DEFAULT clause * pf/pp/ffeqoperators: OID array of operators between columns * old_check_ok: true if this constraint replaces an existing one that * was already validated (thus this one doesn't need validation) * parentDelTrigger and parentUpdTrigger: when recursively called on a * partition, the OIDs of the parent action triggers for DELETE and * UPDATE respectively. * with_period: true if this is a temporal FK */ static void addFkRecurseReferenced(Constraint *fkconstraint, Relation rel, Relation pkrel, Oid indexOid, Oid parentConstr, int numfks, int16 *pkattnum, int16 *fkattnum, Oid *pfeqoperators, Oid *ppeqoperators, Oid *ffeqoperators, int numfkdelsetcols, int16 *fkdelsetcols, bool old_check_ok, Oid parentDelTrigger, Oid parentUpdTrigger, bool with_period) { Oid deleteTriggerOid = InvalidOid, updateTriggerOid = InvalidOid; Assert(CheckRelationLockedByMe(pkrel, ShareRowExclusiveLock, true)); Assert(CheckRelationLockedByMe(rel, ShareRowExclusiveLock, true)); /* * Create action triggers to enforce the constraint, or skip them if the * constraint is NOT ENFORCED. */ if (fkconstraint->is_enforced) createForeignKeyActionTriggers(RelationGetRelid(rel), RelationGetRelid(pkrel), fkconstraint, parentConstr, indexOid, parentDelTrigger, parentUpdTrigger, &deleteTriggerOid, &updateTriggerOid); /* * If the referenced table is partitioned, recurse on ourselves to handle * each partition. We need one pg_constraint row created for each * partition in addition to the pg_constraint row for the parent table. */ if (pkrel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) { PartitionDesc pd = RelationGetPartitionDesc(pkrel, true); for (int i = 0; i < pd->nparts; i++) { Relation partRel; AttrMap *map; AttrNumber *mapped_pkattnum; Oid partIndexId; ObjectAddress address; /* XXX would it be better to acquire these locks beforehand? */ partRel = table_open(pd->oids[i], ShareRowExclusiveLock); /* * Map the attribute numbers in the referenced side of the FK * definition to match the partition's column layout. */ map = build_attrmap_by_name_if_req(RelationGetDescr(partRel), RelationGetDescr(pkrel), false); if (map) { mapped_pkattnum = palloc_array(AttrNumber, numfks); for (int j = 0; j < numfks; j++) mapped_pkattnum[j] = map->attnums[pkattnum[j] - 1]; } else mapped_pkattnum = pkattnum; /* Determine the index to use at this level */ partIndexId = index_get_partition(partRel, indexOid); if (!OidIsValid(partIndexId)) elog(ERROR, "index for %u not found in partition %s", indexOid, RelationGetRelationName(partRel)); /* Create entry at this level ... */ address = addFkConstraint(addFkReferencedSide, fkconstraint->conname, fkconstraint, rel, partRel, partIndexId, parentConstr, numfks, mapped_pkattnum, fkattnum, pfeqoperators, ppeqoperators, ffeqoperators, numfkdelsetcols, fkdelsetcols, true, with_period); /* ... and recurse to our children */ addFkRecurseReferenced(fkconstraint, rel, partRel, partIndexId, address.objectId, numfks, mapped_pkattnum, fkattnum, pfeqoperators, ppeqoperators, ffeqoperators, numfkdelsetcols, fkdelsetcols, old_check_ok, deleteTriggerOid, updateTriggerOid, with_period); /* Done -- clean up (but keep the lock) */ table_close(partRel, NoLock); if (map) { pfree(mapped_pkattnum); free_attrmap(map); } } } } /* * addFkRecurseReferencing * Recursive helper for the referencing side of foreign key creation, * which creates the check triggers and recurses * * If the referencing relation is a plain relation, create the necessary check * triggers that implement the constraint, and set up for Phase 3 constraint * verification. If the referencing relation is a partitioned table, then * we create a pg_constraint row for it and recurse on this routine for each * partition. * * We assume that the referenced relation is locked against concurrent * deletions. If it's a partitioned relation, every partition must be so * locked. * * wqueue: the ALTER TABLE work queue; NULL when not running as part * of an ALTER TABLE sequence. * fkconstraint: the constraint being added * rel: the referencing relation; might be a partition, if recursing * pkrel: the root referenced relation * indexOid: the OID of the index (on pkrel) implementing this constraint * parentConstr: the OID of the parent constraint (there is always one) * numfks: the number of columns in the foreign key * pkattnum: the attnum array of referenced attributes * fkattnum: the attnum array of referencing attributes * pf/pp/ffeqoperators: OID array of operators between columns * numfkdelsetcols: the number of columns in the ON DELETE SET NULL/DEFAULT * (...) clause * fkdelsetcols: the attnum array of the columns in the ON DELETE SET * NULL/DEFAULT clause * old_check_ok: true if this constraint replaces an existing one that * was already validated (thus this one doesn't need validation) * lockmode: the lockmode to acquire on partitions when recursing * parentInsTrigger and parentUpdTrigger: when being recursively called on * a partition, the OIDs of the parent check triggers for INSERT and * UPDATE respectively. * with_period: true if this is a temporal FK */ static void addFkRecurseReferencing(List **wqueue, Constraint *fkconstraint, Relation rel, Relation pkrel, Oid indexOid, Oid parentConstr, int numfks, int16 *pkattnum, int16 *fkattnum, Oid *pfeqoperators, Oid *ppeqoperators, Oid *ffeqoperators, int numfkdelsetcols, int16 *fkdelsetcols, bool old_check_ok, LOCKMODE lockmode, Oid parentInsTrigger, Oid parentUpdTrigger, bool with_period) { Oid insertTriggerOid = InvalidOid, updateTriggerOid = InvalidOid; Assert(OidIsValid(parentConstr)); Assert(CheckRelationLockedByMe(rel, ShareRowExclusiveLock, true)); Assert(CheckRelationLockedByMe(pkrel, ShareRowExclusiveLock, true)); if (rel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("foreign key constraints are not supported on foreign tables"))); /* * Add check triggers if the constraint is ENFORCED, and if needed, * schedule them to be checked in Phase 3. * * If the relation is partitioned, drill down to do it to its partitions. */ if (fkconstraint->is_enforced) createForeignKeyCheckTriggers(RelationGetRelid(rel), RelationGetRelid(pkrel), fkconstraint, parentConstr, indexOid, parentInsTrigger, parentUpdTrigger, &insertTriggerOid, &updateTriggerOid); if (rel->rd_rel->relkind == RELKIND_RELATION) { /* * Tell Phase 3 to check that the constraint is satisfied by existing * rows. We can skip this during table creation, when constraint is * specified as NOT ENFORCED, or when requested explicitly by * specifying NOT VALID in an ADD FOREIGN KEY command, and when we're * recreating a constraint following a SET DATA TYPE operation that * did not impugn its validity. */ if (wqueue && !old_check_ok && !fkconstraint->skip_validation && fkconstraint->is_enforced) { NewConstraint *newcon; AlteredTableInfo *tab; tab = ATGetQueueEntry(wqueue, rel); newcon = palloc0_object(NewConstraint); newcon->name = get_constraint_name(parentConstr); newcon->contype = CONSTR_FOREIGN; newcon->refrelid = RelationGetRelid(pkrel); newcon->refindid = indexOid; newcon->conid = parentConstr; newcon->conwithperiod = fkconstraint->fk_with_period; newcon->qual = (Node *) fkconstraint; tab->constraints = lappend(tab->constraints, newcon); } } else if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) { PartitionDesc pd = RelationGetPartitionDesc(rel, true); Relation trigrel; /* * Triggers of the foreign keys will be manipulated a bunch of times * in the loop below. To avoid repeatedly opening/closing the trigger * catalog relation, we open it here and pass it to the subroutines * called below. */ trigrel = table_open(TriggerRelationId, RowExclusiveLock); /* * Recurse to take appropriate action on each partition; either we * find an existing constraint to reparent to ours, or we create a new * one. */ for (int i = 0; i < pd->nparts; i++) { Relation partition = table_open(pd->oids[i], lockmode); List *partFKs; AttrMap *attmap; AttrNumber mapped_fkattnum[INDEX_MAX_KEYS]; bool attached; ObjectAddress address; CheckAlterTableIsSafe(partition); attmap = build_attrmap_by_name(RelationGetDescr(partition), RelationGetDescr(rel), false); for (int j = 0; j < numfks; j++) mapped_fkattnum[j] = attmap->attnums[fkattnum[j] - 1]; /* Check whether an existing constraint can be repurposed */ partFKs = copyObject(RelationGetFKeyList(partition)); attached = false; foreach_node(ForeignKeyCacheInfo, fk, partFKs) { if (tryAttachPartitionForeignKey(wqueue, fk, partition, parentConstr, numfks, mapped_fkattnum, pkattnum, pfeqoperators, insertTriggerOid, updateTriggerOid, trigrel)) { attached = true; break; } } if (attached) { table_close(partition, NoLock); continue; } /* * No luck finding a good constraint to reuse; create our own. */ address = addFkConstraint(addFkReferencingSide, fkconstraint->conname, fkconstraint, partition, pkrel, indexOid, parentConstr, numfks, pkattnum, mapped_fkattnum, pfeqoperators, ppeqoperators, ffeqoperators, numfkdelsetcols, fkdelsetcols, true, with_period); /* call ourselves to finalize the creation and we're done */ addFkRecurseReferencing(wqueue, fkconstraint, partition, pkrel, indexOid, address.objectId, numfks, pkattnum, mapped_fkattnum, pfeqoperators, ppeqoperators, ffeqoperators, numfkdelsetcols, fkdelsetcols, old_check_ok, lockmode, insertTriggerOid, updateTriggerOid, with_period); table_close(partition, NoLock); } table_close(trigrel, RowExclusiveLock); } } /* * CloneForeignKeyConstraints * Clone foreign keys from a partitioned table to a newly acquired * partition. * * partitionRel is a partition of parentRel, so we can be certain that it has * the same columns with the same datatypes. The columns may be in different * order, though. * * wqueue must be passed to set up phase 3 constraint checking, unless the * referencing-side partition is known to be empty (such as in CREATE TABLE / * PARTITION OF). */ static void CloneForeignKeyConstraints(List **wqueue, Relation parentRel, Relation partitionRel) { /* This only works for declarative partitioning */ Assert(parentRel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE); /* * First, clone constraints where the parent is on the referencing side. */ CloneFkReferencing(wqueue, parentRel, partitionRel); /* * Clone constraints for which the parent is on the referenced side. */ CloneFkReferenced(parentRel, partitionRel); } /* * CloneFkReferenced * Subroutine for CloneForeignKeyConstraints * * Find all the FKs that have the parent relation on the referenced side; * clone those constraints to the given partition. This is to be called * when the partition is being created or attached. * * This recurses to partitions, if the relation being attached is partitioned. * Recursion is done by calling addFkRecurseReferenced. */ static void CloneFkReferenced(Relation parentRel, Relation partitionRel) { Relation pg_constraint; AttrMap *attmap; ListCell *cell; SysScanDesc scan; ScanKeyData key[2]; HeapTuple tuple; List *clone = NIL; Relation trigrel; /* * Search for any constraints where this partition's parent is in the * referenced side. However, we must not clone any constraint whose * parent constraint is also going to be cloned, to avoid duplicates. So * do it in two steps: first construct the list of constraints to clone, * then go over that list cloning those whose parents are not in the list. * (We must not rely on the parent being seen first, since the catalog * scan could return children first.) */ pg_constraint = table_open(ConstraintRelationId, RowShareLock); ScanKeyInit(&key[0], Anum_pg_constraint_confrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(parentRel))); ScanKeyInit(&key[1], Anum_pg_constraint_contype, BTEqualStrategyNumber, F_CHAREQ, CharGetDatum(CONSTRAINT_FOREIGN)); /* This is a seqscan, as we don't have a usable index ... */ scan = systable_beginscan(pg_constraint, InvalidOid, true, NULL, 2, key); while ((tuple = systable_getnext(scan)) != NULL) { Form_pg_constraint constrForm = (Form_pg_constraint) GETSTRUCT(tuple); clone = lappend_oid(clone, constrForm->oid); } systable_endscan(scan); table_close(pg_constraint, RowShareLock); /* * Triggers of the foreign keys will be manipulated a bunch of times in * the loop below. To avoid repeatedly opening/closing the trigger * catalog relation, we open it here and pass it to the subroutines called * below. */ trigrel = table_open(TriggerRelationId, RowExclusiveLock); attmap = build_attrmap_by_name(RelationGetDescr(partitionRel), RelationGetDescr(parentRel), false); foreach(cell, clone) { Oid constrOid = lfirst_oid(cell); Form_pg_constraint constrForm; Relation fkRel; Oid indexOid; Oid partIndexId; int numfks; AttrNumber conkey[INDEX_MAX_KEYS]; AttrNumber mapped_confkey[INDEX_MAX_KEYS]; AttrNumber confkey[INDEX_MAX_KEYS]; Oid conpfeqop[INDEX_MAX_KEYS]; Oid conppeqop[INDEX_MAX_KEYS]; Oid conffeqop[INDEX_MAX_KEYS]; int numfkdelsetcols; AttrNumber confdelsetcols[INDEX_MAX_KEYS]; Constraint *fkconstraint; ObjectAddress address; Oid deleteTriggerOid = InvalidOid, updateTriggerOid = InvalidOid; tuple = SearchSysCache1(CONSTROID, ObjectIdGetDatum(constrOid)); if (!HeapTupleIsValid(tuple)) elog(ERROR, "cache lookup failed for constraint %u", constrOid); constrForm = (Form_pg_constraint) GETSTRUCT(tuple); /* * As explained above: don't try to clone a constraint for which we're * going to clone the parent. */ if (list_member_oid(clone, constrForm->conparentid)) { ReleaseSysCache(tuple); continue; } /* We need the same lock level that CreateTrigger will acquire */ fkRel = table_open(constrForm->conrelid, ShareRowExclusiveLock); indexOid = constrForm->conindid; DeconstructFkConstraintRow(tuple, &numfks, conkey, confkey, conpfeqop, conppeqop, conffeqop, &numfkdelsetcols, confdelsetcols); for (int i = 0; i < numfks; i++) mapped_confkey[i] = attmap->attnums[confkey[i] - 1]; fkconstraint = makeNode(Constraint); fkconstraint->contype = CONSTRAINT_FOREIGN; fkconstraint->conname = NameStr(constrForm->conname); fkconstraint->deferrable = constrForm->condeferrable; fkconstraint->initdeferred = constrForm->condeferred; fkconstraint->location = -1; fkconstraint->pktable = NULL; /* ->fk_attrs determined below */ fkconstraint->pk_attrs = NIL; fkconstraint->fk_matchtype = constrForm->confmatchtype; fkconstraint->fk_upd_action = constrForm->confupdtype; fkconstraint->fk_del_action = constrForm->confdeltype; fkconstraint->fk_del_set_cols = NIL; fkconstraint->old_conpfeqop = NIL; fkconstraint->old_pktable_oid = InvalidOid; fkconstraint->is_enforced = constrForm->conenforced; fkconstraint->skip_validation = false; fkconstraint->initially_valid = constrForm->convalidated; /* set up colnames that are used to generate the constraint name */ for (int i = 0; i < numfks; i++) { Form_pg_attribute att; att = TupleDescAttr(RelationGetDescr(fkRel), conkey[i] - 1); fkconstraint->fk_attrs = lappend(fkconstraint->fk_attrs, makeString(NameStr(att->attname))); } /* * Add the new foreign key constraint pointing to the new partition. * Because this new partition appears in the referenced side of the * constraint, we don't need to set up for Phase 3 check. */ partIndexId = index_get_partition(partitionRel, indexOid); if (!OidIsValid(partIndexId)) elog(ERROR, "index for %u not found in partition %s", indexOid, RelationGetRelationName(partitionRel)); /* * Get the "action" triggers belonging to the constraint to pass as * parent OIDs for similar triggers that will be created on the * partition in addFkRecurseReferenced(). */ if (constrForm->conenforced) GetForeignKeyActionTriggers(trigrel, constrOid, constrForm->confrelid, constrForm->conrelid, &deleteTriggerOid, &updateTriggerOid); /* Add this constraint ... */ address = addFkConstraint(addFkReferencedSide, fkconstraint->conname, fkconstraint, fkRel, partitionRel, partIndexId, constrOid, numfks, mapped_confkey, conkey, conpfeqop, conppeqop, conffeqop, numfkdelsetcols, confdelsetcols, false, constrForm->conperiod); /* ... and recurse */ addFkRecurseReferenced(fkconstraint, fkRel, partitionRel, partIndexId, address.objectId, numfks, mapped_confkey, conkey, conpfeqop, conppeqop, conffeqop, numfkdelsetcols, confdelsetcols, true, deleteTriggerOid, updateTriggerOid, constrForm->conperiod); table_close(fkRel, NoLock); ReleaseSysCache(tuple); } table_close(trigrel, RowExclusiveLock); } /* * CloneFkReferencing * Subroutine for CloneForeignKeyConstraints * * For each FK constraint of the parent relation in the given list, find an * equivalent constraint in its partition relation that can be reparented; * if one cannot be found, create a new constraint in the partition as its * child. * * If wqueue is given, it is used to set up phase-3 verification for each * cloned constraint; omit it if such verification is not needed * (example: the partition is being created anew). */ static void CloneFkReferencing(List **wqueue, Relation parentRel, Relation partRel) { AttrMap *attmap; List *partFKs; List *clone = NIL; ListCell *cell; Relation trigrel; /* obtain a list of constraints that we need to clone */ foreach(cell, RelationGetFKeyList(parentRel)) { ForeignKeyCacheInfo *fk = lfirst(cell); /* * Refuse to attach a table as partition that this partitioned table * already has a foreign key to. This isn't useful schema, which is * proven by the fact that there have been no user complaints that * it's already impossible to achieve this in the opposite direction, * i.e., creating a foreign key that references a partition. This * restriction allows us to dodge some complexities around * pg_constraint and pg_trigger row creations that would be needed * during ATTACH/DETACH for this kind of relationship. */ if (fk->confrelid == RelationGetRelid(partRel)) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot attach table \"%s\" as a partition because it is referenced by foreign key \"%s\"", RelationGetRelationName(partRel), get_constraint_name(fk->conoid)))); clone = lappend_oid(clone, fk->conoid); } /* * Silently do nothing if there's nothing to do. In particular, this * avoids throwing a spurious error for foreign tables. */ if (clone == NIL) return; if (partRel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("foreign key constraints are not supported on foreign tables"))); /* * Triggers of the foreign keys will be manipulated a bunch of times in * the loop below. To avoid repeatedly opening/closing the trigger * catalog relation, we open it here and pass it to the subroutines called * below. */ trigrel = table_open(TriggerRelationId, RowExclusiveLock); /* * The constraint key may differ, if the columns in the partition are * different. This map is used to convert them. */ attmap = build_attrmap_by_name(RelationGetDescr(partRel), RelationGetDescr(parentRel), false); partFKs = copyObject(RelationGetFKeyList(partRel)); foreach(cell, clone) { Oid parentConstrOid = lfirst_oid(cell); Form_pg_constraint constrForm; Relation pkrel; HeapTuple tuple; int numfks; AttrNumber conkey[INDEX_MAX_KEYS]; AttrNumber mapped_conkey[INDEX_MAX_KEYS]; AttrNumber confkey[INDEX_MAX_KEYS]; Oid conpfeqop[INDEX_MAX_KEYS]; Oid conppeqop[INDEX_MAX_KEYS]; Oid conffeqop[INDEX_MAX_KEYS]; int numfkdelsetcols; AttrNumber confdelsetcols[INDEX_MAX_KEYS]; Constraint *fkconstraint; bool attached; Oid indexOid; ObjectAddress address; ListCell *lc; Oid insertTriggerOid = InvalidOid, updateTriggerOid = InvalidOid; bool with_period; tuple = SearchSysCache1(CONSTROID, ObjectIdGetDatum(parentConstrOid)); if (!HeapTupleIsValid(tuple)) elog(ERROR, "cache lookup failed for constraint %u", parentConstrOid); constrForm = (Form_pg_constraint) GETSTRUCT(tuple); /* Don't clone constraints whose parents are being cloned */ if (list_member_oid(clone, constrForm->conparentid)) { ReleaseSysCache(tuple); continue; } /* * Need to prevent concurrent deletions. If pkrel is a partitioned * relation, that means to lock all partitions. */ pkrel = table_open(constrForm->confrelid, ShareRowExclusiveLock); if (pkrel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) (void) find_all_inheritors(RelationGetRelid(pkrel), ShareRowExclusiveLock, NULL); DeconstructFkConstraintRow(tuple, &numfks, conkey, confkey, conpfeqop, conppeqop, conffeqop, &numfkdelsetcols, confdelsetcols); for (int i = 0; i < numfks; i++) mapped_conkey[i] = attmap->attnums[conkey[i] - 1]; /* * Get the "check" triggers belonging to the constraint, if it is * ENFORCED, to pass as parent OIDs for similar triggers that will be * created on the partition in addFkRecurseReferencing(). They are * also passed to tryAttachPartitionForeignKey() below to simply * assign as parents to the partition's existing "check" triggers, * that is, if the corresponding constraints is deemed attachable to * the parent constraint. */ if (constrForm->conenforced) GetForeignKeyCheckTriggers(trigrel, constrForm->oid, constrForm->confrelid, constrForm->conrelid, &insertTriggerOid, &updateTriggerOid); /* * Before creating a new constraint, see whether any existing FKs are * fit for the purpose. If one is, attach the parent constraint to * it, and don't clone anything. This way we avoid the expensive * verification step and don't end up with a duplicate FK, and we * don't need to recurse to partitions for this constraint. */ attached = false; foreach(lc, partFKs) { ForeignKeyCacheInfo *fk = lfirst_node(ForeignKeyCacheInfo, lc); if (tryAttachPartitionForeignKey(wqueue, fk, partRel, parentConstrOid, numfks, mapped_conkey, confkey, conpfeqop, insertTriggerOid, updateTriggerOid, trigrel)) { attached = true; table_close(pkrel, NoLock); break; } } if (attached) { ReleaseSysCache(tuple); continue; } /* No dice. Set up to create our own constraint */ fkconstraint = makeNode(Constraint); fkconstraint->contype = CONSTRAINT_FOREIGN; /* ->conname determined below */ fkconstraint->deferrable = constrForm->condeferrable; fkconstraint->initdeferred = constrForm->condeferred; fkconstraint->location = -1; fkconstraint->pktable = NULL; /* ->fk_attrs determined below */ fkconstraint->pk_attrs = NIL; fkconstraint->fk_matchtype = constrForm->confmatchtype; fkconstraint->fk_upd_action = constrForm->confupdtype; fkconstraint->fk_del_action = constrForm->confdeltype; fkconstraint->fk_del_set_cols = NIL; fkconstraint->old_conpfeqop = NIL; fkconstraint->old_pktable_oid = InvalidOid; fkconstraint->is_enforced = constrForm->conenforced; fkconstraint->skip_validation = false; fkconstraint->initially_valid = constrForm->convalidated; for (int i = 0; i < numfks; i++) { Form_pg_attribute att; att = TupleDescAttr(RelationGetDescr(partRel), mapped_conkey[i] - 1); fkconstraint->fk_attrs = lappend(fkconstraint->fk_attrs, makeString(NameStr(att->attname))); } indexOid = constrForm->conindid; with_period = constrForm->conperiod; /* Create the pg_constraint entry at this level */ address = addFkConstraint(addFkReferencingSide, NameStr(constrForm->conname), fkconstraint, partRel, pkrel, indexOid, parentConstrOid, numfks, confkey, mapped_conkey, conpfeqop, conppeqop, conffeqop, numfkdelsetcols, confdelsetcols, false, with_period); /* Done with the cloned constraint's tuple */ ReleaseSysCache(tuple); /* Create the check triggers, and recurse to partitions, if any */ addFkRecurseReferencing(wqueue, fkconstraint, partRel, pkrel, indexOid, address.objectId, numfks, confkey, mapped_conkey, conpfeqop, conppeqop, conffeqop, numfkdelsetcols, confdelsetcols, false, /* no old check exists */ AccessExclusiveLock, insertTriggerOid, updateTriggerOid, with_period); table_close(pkrel, NoLock); } table_close(trigrel, RowExclusiveLock); } /* * When the parent of a partition receives [the referencing side of] a foreign * key, we must propagate that foreign key to the partition. However, the * partition might already have an equivalent foreign key; this routine * compares the given ForeignKeyCacheInfo (in the partition) to the FK defined * by the other parameters. If they are equivalent, create the link between * the two constraints and return true. * * If the given FK does not match the one defined by rest of the params, * return false. */ static bool tryAttachPartitionForeignKey(List **wqueue, ForeignKeyCacheInfo *fk, Relation partition, Oid parentConstrOid, int numfks, AttrNumber *mapped_conkey, AttrNumber *confkey, Oid *conpfeqop, Oid parentInsTrigger, Oid parentUpdTrigger, Relation trigrel) { HeapTuple parentConstrTup; Form_pg_constraint parentConstr; HeapTuple partcontup; Form_pg_constraint partConstr; parentConstrTup = SearchSysCache1(CONSTROID, ObjectIdGetDatum(parentConstrOid)); if (!HeapTupleIsValid(parentConstrTup)) elog(ERROR, "cache lookup failed for constraint %u", parentConstrOid); parentConstr = (Form_pg_constraint) GETSTRUCT(parentConstrTup); /* * Do some quick & easy initial checks. If any of these fail, we cannot * use this constraint. */ if (fk->confrelid != parentConstr->confrelid || fk->nkeys != numfks) { ReleaseSysCache(parentConstrTup); return false; } for (int i = 0; i < numfks; i++) { if (fk->conkey[i] != mapped_conkey[i] || fk->confkey[i] != confkey[i] || fk->conpfeqop[i] != conpfeqop[i]) { ReleaseSysCache(parentConstrTup); return false; } } /* Looks good so far; perform more extensive checks. */ partcontup = SearchSysCache1(CONSTROID, ObjectIdGetDatum(fk->conoid)); if (!HeapTupleIsValid(partcontup)) elog(ERROR, "cache lookup failed for constraint %u", fk->conoid); partConstr = (Form_pg_constraint) GETSTRUCT(partcontup); /* * An error should be raised if the constraint enforceability is * different. Returning false without raising an error, as we do for other * attributes, could lead to a duplicate constraint with the same * enforceability as the parent. While this may be acceptable, it may not * be ideal. Therefore, it's better to raise an error and allow the user * to correct the enforceability before proceeding. */ if (partConstr->conenforced != parentConstr->conenforced) ereport(ERROR, (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), errmsg("constraint \"%s\" enforceability conflicts with constraint \"%s\" on relation \"%s\"", NameStr(parentConstr->conname), NameStr(partConstr->conname), RelationGetRelationName(partition)))); if (OidIsValid(partConstr->conparentid) || partConstr->condeferrable != parentConstr->condeferrable || partConstr->condeferred != parentConstr->condeferred || partConstr->confupdtype != parentConstr->confupdtype || partConstr->confdeltype != parentConstr->confdeltype || partConstr->confmatchtype != parentConstr->confmatchtype) { ReleaseSysCache(parentConstrTup); ReleaseSysCache(partcontup); return false; } ReleaseSysCache(parentConstrTup); ReleaseSysCache(partcontup); /* Looks good! Attach this constraint. */ AttachPartitionForeignKey(wqueue, partition, fk->conoid, parentConstrOid, parentInsTrigger, parentUpdTrigger, trigrel); return true; } /* * AttachPartitionForeignKey * * The subroutine for tryAttachPartitionForeignKey performs the final tasks of * attaching the constraint, removing redundant triggers and entries from * pg_constraint, and setting the constraint's parent. */ static void AttachPartitionForeignKey(List **wqueue, Relation partition, Oid partConstrOid, Oid parentConstrOid, Oid parentInsTrigger, Oid parentUpdTrigger, Relation trigrel) { HeapTuple parentConstrTup; Form_pg_constraint parentConstr; HeapTuple partcontup; Form_pg_constraint partConstr; bool queueValidation; Oid partConstrFrelid; Oid partConstrRelid; bool parentConstrIsEnforced; /* Fetch the parent constraint tuple */ parentConstrTup = SearchSysCache1(CONSTROID, ObjectIdGetDatum(parentConstrOid)); if (!HeapTupleIsValid(parentConstrTup)) elog(ERROR, "cache lookup failed for constraint %u", parentConstrOid); parentConstr = (Form_pg_constraint) GETSTRUCT(parentConstrTup); parentConstrIsEnforced = parentConstr->conenforced; /* Fetch the child constraint tuple */ partcontup = SearchSysCache1(CONSTROID, ObjectIdGetDatum(partConstrOid)); if (!HeapTupleIsValid(partcontup)) elog(ERROR, "cache lookup failed for constraint %u", partConstrOid); partConstr = (Form_pg_constraint) GETSTRUCT(partcontup); partConstrFrelid = partConstr->confrelid; partConstrRelid = partConstr->conrelid; /* * If the referenced table is partitioned, then the partition we're * attaching now has extra pg_constraint rows and action triggers that are * no longer needed. Remove those. */ if (get_rel_relkind(partConstrFrelid) == RELKIND_PARTITIONED_TABLE) { Relation pg_constraint = table_open(ConstraintRelationId, RowShareLock); RemoveInheritedConstraint(pg_constraint, trigrel, partConstrOid, partConstrRelid); table_close(pg_constraint, RowShareLock); } /* * Will we need to validate this constraint? A valid parent constraint * implies that all child constraints have been validated, so if this one * isn't, we must trigger phase 3 validation. */ queueValidation = parentConstr->convalidated && !partConstr->convalidated; ReleaseSysCache(partcontup); ReleaseSysCache(parentConstrTup); /* * The action triggers in the new partition become redundant -- the parent * table already has equivalent ones, and those will be able to reach the * partition. Remove the ones in the partition. We identify them because * they have our constraint OID, as well as being on the referenced rel. */ DropForeignKeyConstraintTriggers(trigrel, partConstrOid, partConstrFrelid, partConstrRelid); ConstraintSetParentConstraint(partConstrOid, parentConstrOid, RelationGetRelid(partition)); /* * Like the constraint, attach partition's "check" triggers to the * corresponding parent triggers if the constraint is ENFORCED. NOT * ENFORCED constraints do not have these triggers. */ if (parentConstrIsEnforced) { Oid insertTriggerOid, updateTriggerOid; GetForeignKeyCheckTriggers(trigrel, partConstrOid, partConstrFrelid, partConstrRelid, &insertTriggerOid, &updateTriggerOid); Assert(OidIsValid(insertTriggerOid) && OidIsValid(parentInsTrigger)); TriggerSetParentTrigger(trigrel, insertTriggerOid, parentInsTrigger, RelationGetRelid(partition)); Assert(OidIsValid(updateTriggerOid) && OidIsValid(parentUpdTrigger)); TriggerSetParentTrigger(trigrel, updateTriggerOid, parentUpdTrigger, RelationGetRelid(partition)); } /* * We updated this pg_constraint row above to set its parent; validating * it will cause its convalidated flag to change, so we need CCI here. In * addition, we need it unconditionally for the rare case where the parent * table has *two* identical constraints; when reaching this function for * the second one, we must have made our changes visible, otherwise we * would try to attach both to this one. */ CommandCounterIncrement(); /* If validation is needed, put it in the queue now. */ if (queueValidation) { Relation conrel; Oid confrelid; conrel = table_open(ConstraintRelationId, RowExclusiveLock); partcontup = SearchSysCache1(CONSTROID, ObjectIdGetDatum(partConstrOid)); if (!HeapTupleIsValid(partcontup)) elog(ERROR, "cache lookup failed for constraint %u", partConstrOid); confrelid = ((Form_pg_constraint) GETSTRUCT(partcontup))->confrelid; /* Use the same lock as for AT_ValidateConstraint */ QueueFKConstraintValidation(wqueue, conrel, partition, confrelid, partcontup, ShareUpdateExclusiveLock); ReleaseSysCache(partcontup); table_close(conrel, RowExclusiveLock); } } /* * RemoveInheritedConstraint * * Removes the constraint and its associated trigger from the specified * relation, which inherited the given constraint. */ static void RemoveInheritedConstraint(Relation conrel, Relation trigrel, Oid conoid, Oid conrelid) { ObjectAddresses *objs; HeapTuple consttup; ScanKeyData key; SysScanDesc scan; HeapTuple trigtup; ScanKeyInit(&key, Anum_pg_constraint_conrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(conrelid)); scan = systable_beginscan(conrel, ConstraintRelidTypidNameIndexId, true, NULL, 1, &key); objs = new_object_addresses(); while ((consttup = systable_getnext(scan)) != NULL) { Form_pg_constraint conform = (Form_pg_constraint) GETSTRUCT(consttup); if (conform->conparentid != conoid) continue; else { ObjectAddress addr; SysScanDesc scan2; ScanKeyData key2; int n PG_USED_FOR_ASSERTS_ONLY; ObjectAddressSet(addr, ConstraintRelationId, conform->oid); add_exact_object_address(&addr, objs); /* * First we must delete the dependency record that binds the * constraint records together. */ n = deleteDependencyRecordsForSpecific(ConstraintRelationId, conform->oid, DEPENDENCY_INTERNAL, ConstraintRelationId, conoid); Assert(n == 1); /* actually only one is expected */ /* * Now search for the triggers for this constraint and set them up * for deletion too */ ScanKeyInit(&key2, Anum_pg_trigger_tgconstraint, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(conform->oid)); scan2 = systable_beginscan(trigrel, TriggerConstraintIndexId, true, NULL, 1, &key2); while ((trigtup = systable_getnext(scan2)) != NULL) { ObjectAddressSet(addr, TriggerRelationId, ((Form_pg_trigger) GETSTRUCT(trigtup))->oid); add_exact_object_address(&addr, objs); } systable_endscan(scan2); } } /* make the dependency deletions visible */ CommandCounterIncrement(); performMultipleDeletions(objs, DROP_RESTRICT, PERFORM_DELETION_INTERNAL); systable_endscan(scan); } /* * DropForeignKeyConstraintTriggers * * The subroutine for tryAttachPartitionForeignKey handles the deletion of * action triggers for the foreign key constraint. * * If valid confrelid and conrelid values are not provided, the respective * trigger check will be skipped, and the trigger will be considered for * removal. */ static void DropForeignKeyConstraintTriggers(Relation trigrel, Oid conoid, Oid confrelid, Oid conrelid) { ScanKeyData key; SysScanDesc scan; HeapTuple trigtup; ScanKeyInit(&key, Anum_pg_trigger_tgconstraint, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(conoid)); scan = systable_beginscan(trigrel, TriggerConstraintIndexId, true, NULL, 1, &key); while ((trigtup = systable_getnext(scan)) != NULL) { Form_pg_trigger trgform = (Form_pg_trigger) GETSTRUCT(trigtup); ObjectAddress trigger; /* Invalid if trigger is not for a referential integrity constraint */ if (!OidIsValid(trgform->tgconstrrelid)) continue; if (OidIsValid(conrelid) && trgform->tgconstrrelid != conrelid) continue; if (OidIsValid(confrelid) && trgform->tgrelid != confrelid) continue; /* We should be dropping trigger related to foreign key constraint */ Assert(trgform->tgfoid == F_RI_FKEY_CHECK_INS || trgform->tgfoid == F_RI_FKEY_CHECK_UPD || trgform->tgfoid == F_RI_FKEY_CASCADE_DEL || trgform->tgfoid == F_RI_FKEY_CASCADE_UPD || trgform->tgfoid == F_RI_FKEY_RESTRICT_DEL || trgform->tgfoid == F_RI_FKEY_RESTRICT_UPD || trgform->tgfoid == F_RI_FKEY_SETNULL_DEL || trgform->tgfoid == F_RI_FKEY_SETNULL_UPD || trgform->tgfoid == F_RI_FKEY_SETDEFAULT_DEL || trgform->tgfoid == F_RI_FKEY_SETDEFAULT_UPD || trgform->tgfoid == F_RI_FKEY_NOACTION_DEL || trgform->tgfoid == F_RI_FKEY_NOACTION_UPD); /* * The constraint is originally set up to contain this trigger as an * implementation object, so there's a dependency record that links * the two; however, since the trigger is no longer needed, we remove * the dependency link in order to be able to drop the trigger while * keeping the constraint intact. */ deleteDependencyRecordsFor(TriggerRelationId, trgform->oid, false); /* make dependency deletion visible to performDeletion */ CommandCounterIncrement(); ObjectAddressSet(trigger, TriggerRelationId, trgform->oid); performDeletion(&trigger, DROP_RESTRICT, 0); /* make trigger drop visible, in case the loop iterates */ CommandCounterIncrement(); } systable_endscan(scan); } /* * GetForeignKeyActionTriggers * Returns delete and update "action" triggers of the given relation * belonging to the given constraint */ static void GetForeignKeyActionTriggers(Relation trigrel, Oid conoid, Oid confrelid, Oid conrelid, Oid *deleteTriggerOid, Oid *updateTriggerOid) { ScanKeyData key; SysScanDesc scan; HeapTuple trigtup; *deleteTriggerOid = *updateTriggerOid = InvalidOid; ScanKeyInit(&key, Anum_pg_trigger_tgconstraint, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(conoid)); scan = systable_beginscan(trigrel, TriggerConstraintIndexId, true, NULL, 1, &key); while ((trigtup = systable_getnext(scan)) != NULL) { Form_pg_trigger trgform = (Form_pg_trigger) GETSTRUCT(trigtup); if (trgform->tgconstrrelid != conrelid) continue; if (trgform->tgrelid != confrelid) continue; /* Only ever look at "action" triggers on the PK side. */ if (RI_FKey_trigger_type(trgform->tgfoid) != RI_TRIGGER_PK) continue; if (TRIGGER_FOR_DELETE(trgform->tgtype)) { Assert(*deleteTriggerOid == InvalidOid); *deleteTriggerOid = trgform->oid; } else if (TRIGGER_FOR_UPDATE(trgform->tgtype)) { Assert(*updateTriggerOid == InvalidOid); *updateTriggerOid = trgform->oid; } #ifndef USE_ASSERT_CHECKING /* In an assert-enabled build, continue looking to find duplicates */ if (OidIsValid(*deleteTriggerOid) && OidIsValid(*updateTriggerOid)) break; #endif } if (!OidIsValid(*deleteTriggerOid)) elog(ERROR, "could not find ON DELETE action trigger of foreign key constraint %u", conoid); if (!OidIsValid(*updateTriggerOid)) elog(ERROR, "could not find ON UPDATE action trigger of foreign key constraint %u", conoid); systable_endscan(scan); } /* * GetForeignKeyCheckTriggers * Returns insert and update "check" triggers of the given relation * belonging to the given constraint */ static void GetForeignKeyCheckTriggers(Relation trigrel, Oid conoid, Oid confrelid, Oid conrelid, Oid *insertTriggerOid, Oid *updateTriggerOid) { ScanKeyData key; SysScanDesc scan; HeapTuple trigtup; *insertTriggerOid = *updateTriggerOid = InvalidOid; ScanKeyInit(&key, Anum_pg_trigger_tgconstraint, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(conoid)); scan = systable_beginscan(trigrel, TriggerConstraintIndexId, true, NULL, 1, &key); while ((trigtup = systable_getnext(scan)) != NULL) { Form_pg_trigger trgform = (Form_pg_trigger) GETSTRUCT(trigtup); if (trgform->tgconstrrelid != confrelid) continue; if (trgform->tgrelid != conrelid) continue; /* Only ever look at "check" triggers on the FK side. */ if (RI_FKey_trigger_type(trgform->tgfoid) != RI_TRIGGER_FK) continue; if (TRIGGER_FOR_INSERT(trgform->tgtype)) { Assert(*insertTriggerOid == InvalidOid); *insertTriggerOid = trgform->oid; } else if (TRIGGER_FOR_UPDATE(trgform->tgtype)) { Assert(*updateTriggerOid == InvalidOid); *updateTriggerOid = trgform->oid; } #ifndef USE_ASSERT_CHECKING /* In an assert-enabled build, continue looking to find duplicates. */ if (OidIsValid(*insertTriggerOid) && OidIsValid(*updateTriggerOid)) break; #endif } if (!OidIsValid(*insertTriggerOid)) elog(ERROR, "could not find ON INSERT check triggers of foreign key constraint %u", conoid); if (!OidIsValid(*updateTriggerOid)) elog(ERROR, "could not find ON UPDATE check triggers of foreign key constraint %u", conoid); systable_endscan(scan); } /* * ALTER TABLE ALTER CONSTRAINT * * Update the attributes of a constraint. * * Currently works for Foreign Key, Check, and not null constraints. * * If the constraint is modified, returns its address; otherwise, return * InvalidObjectAddress. */ static ObjectAddress ATExecAlterConstraint(List **wqueue, Relation rel, ATAlterConstraint *cmdcon, bool recurse, LOCKMODE lockmode) { Relation conrel; Relation tgrel; SysScanDesc scan; ScanKeyData skey[3]; HeapTuple contuple; Form_pg_constraint currcon; ObjectAddress address; /* * Disallow altering ONLY a partitioned table, as it would make no sense. * This is okay for legacy inheritance. */ if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE && !recurse) ereport(ERROR, errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("constraint must be altered in child tables too"), errhint("Do not specify the ONLY keyword.")); conrel = table_open(ConstraintRelationId, RowExclusiveLock); tgrel = table_open(TriggerRelationId, RowExclusiveLock); /* * Find and check the target constraint */ ScanKeyInit(&skey[0], Anum_pg_constraint_conrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(rel))); ScanKeyInit(&skey[1], Anum_pg_constraint_contypid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(InvalidOid)); ScanKeyInit(&skey[2], Anum_pg_constraint_conname, BTEqualStrategyNumber, F_NAMEEQ, CStringGetDatum(cmdcon->conname)); scan = systable_beginscan(conrel, ConstraintRelidTypidNameIndexId, true, NULL, 3, skey); /* There can be at most one matching row */ if (!HeapTupleIsValid(contuple = systable_getnext(scan))) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_OBJECT), errmsg("constraint \"%s\" of relation \"%s\" does not exist", cmdcon->conname, RelationGetRelationName(rel)))); currcon = (Form_pg_constraint) GETSTRUCT(contuple); if (cmdcon->alterDeferrability && currcon->contype != CONSTRAINT_FOREIGN) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("constraint \"%s\" of relation \"%s\" is not a foreign key constraint", cmdcon->conname, RelationGetRelationName(rel)))); if (cmdcon->alterEnforceability && (currcon->contype != CONSTRAINT_FOREIGN && currcon->contype != CONSTRAINT_CHECK)) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot alter enforceability of constraint \"%s\" of relation \"%s\"", cmdcon->conname, RelationGetRelationName(rel)), errhint("Only foreign key and check constraints can change enforceability."))); if (cmdcon->alterInheritability && currcon->contype != CONSTRAINT_NOTNULL) ereport(ERROR, errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("constraint \"%s\" of relation \"%s\" is not a not-null constraint", cmdcon->conname, RelationGetRelationName(rel))); if (cmdcon->alterInheritability && cmdcon->noinherit && rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) ereport(ERROR, errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("not-null constraint \"%s\" on partitioned table \"%s\" cannot be NO INHERIT", cmdcon->conname, RelationGetRelationName(rel))); /* Refuse to modify inheritability of inherited constraints */ if (cmdcon->alterInheritability && cmdcon->noinherit && currcon->coninhcount > 0) ereport(ERROR, errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("cannot alter inherited constraint \"%s\" on relation \"%s\"", NameStr(currcon->conname), RelationGetRelationName(rel))); /* * If it's not the topmost constraint, raise an error. * * Altering a non-topmost constraint leaves some triggers untouched, since * they are not directly connected to this constraint; also, pg_dump would * ignore the deferrability status of the individual constraint, since it * only dumps topmost constraints. Avoid these problems by refusing this * operation and telling the user to alter the parent constraint instead. */ if (OidIsValid(currcon->conparentid)) { HeapTuple tp; Oid parent = currcon->conparentid; char *ancestorname = NULL; char *ancestortable = NULL; /* Loop to find the topmost constraint */ while (HeapTupleIsValid(tp = SearchSysCache1(CONSTROID, ObjectIdGetDatum(parent)))) { Form_pg_constraint contup = (Form_pg_constraint) GETSTRUCT(tp); /* If no parent, this is the constraint we want */ if (!OidIsValid(contup->conparentid)) { ancestorname = pstrdup(NameStr(contup->conname)); ancestortable = get_rel_name(contup->conrelid); ReleaseSysCache(tp); break; } parent = contup->conparentid; ReleaseSysCache(tp); } ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("cannot alter constraint \"%s\" on relation \"%s\"", cmdcon->conname, RelationGetRelationName(rel)), ancestorname && ancestortable ? errdetail("Constraint \"%s\" is derived from constraint \"%s\" of relation \"%s\".", cmdcon->conname, ancestorname, ancestortable) : 0, errhint("You may alter the constraint it derives from instead."))); } address = InvalidObjectAddress; /* * Do the actual catalog work, and recurse if necessary. */ if (ATExecAlterConstraintInternal(wqueue, cmdcon, conrel, tgrel, rel, contuple, recurse, lockmode)) ObjectAddressSet(address, ConstraintRelationId, currcon->oid); systable_endscan(scan); table_close(tgrel, RowExclusiveLock); table_close(conrel, RowExclusiveLock); return address; } /* * A subroutine of ATExecAlterConstraint that calls the respective routines for * altering constraint's enforceability, deferrability or inheritability. */ static bool ATExecAlterConstraintInternal(List **wqueue, ATAlterConstraint *cmdcon, Relation conrel, Relation tgrel, Relation rel, HeapTuple contuple, bool recurse, LOCKMODE lockmode) { Form_pg_constraint currcon; bool changed = false; List *otherrelids = NIL; currcon = (Form_pg_constraint) GETSTRUCT(contuple); /* * Do the catalog work for the enforceability or deferrability change, * recurse if necessary. * * Note that even if deferrability is requested to be altered along with * enforceability, we don't need to explicitly update multiple entries in * pg_trigger related to deferrability. * * Modifying foreign key enforceability involves either creating or * dropping the trigger, during which the deferrability setting will be * adjusted automatically. */ if (cmdcon->alterEnforceability) { if (currcon->contype == CONSTRAINT_FOREIGN) changed = ATExecAlterFKConstrEnforceability(wqueue, cmdcon, conrel, tgrel, currcon->conrelid, currcon->confrelid, contuple, lockmode, InvalidOid, InvalidOid, InvalidOid, InvalidOid); else if (currcon->contype == CONSTRAINT_CHECK) changed = ATExecAlterCheckConstrEnforceability(wqueue, cmdcon, conrel, contuple, recurse, false, NIL, lockmode); } else if (cmdcon->alterDeferrability && ATExecAlterConstrDeferrability(wqueue, cmdcon, conrel, tgrel, rel, contuple, recurse, &otherrelids, lockmode)) { /* * AlterConstrUpdateConstraintEntry already invalidated relcache for * the relations having the constraint itself; here we also invalidate * for relations that have any triggers that are part of the * constraint. */ foreach_oid(relid, otherrelids) CacheInvalidateRelcacheByRelid(relid); changed = true; } /* * Do the catalog work for the inheritability change. */ if (cmdcon->alterInheritability && ATExecAlterConstrInheritability(wqueue, cmdcon, conrel, rel, contuple, lockmode)) changed = true; return changed; } /* * Returns true if the foreign key constraint's enforceability is altered. * * Depending on whether the constraint is being set to ENFORCED or NOT * ENFORCED, it creates or drops the trigger accordingly. * * Note that we must recurse even when trying to change a constraint to not * enforced if it is already not enforced, in case descendant constraints * might be enforced and need to be changed to not enforced. Conversely, we * should do nothing if a constraint is being set to enforced and is already * enforced, as descendant constraints cannot be different in that case. */ static bool ATExecAlterFKConstrEnforceability(List **wqueue, ATAlterConstraint *cmdcon, Relation conrel, Relation tgrel, Oid fkrelid, Oid pkrelid, HeapTuple contuple, LOCKMODE lockmode, Oid ReferencedParentDelTrigger, Oid ReferencedParentUpdTrigger, Oid ReferencingParentInsTrigger, Oid ReferencingParentUpdTrigger) { Form_pg_constraint currcon; Oid conoid; Relation rel; bool changed = false; /* Since this function recurses, it could be driven to stack overflow */ check_stack_depth(); Assert(cmdcon->alterEnforceability); currcon = (Form_pg_constraint) GETSTRUCT(contuple); conoid = currcon->oid; /* Should be foreign key constraint */ Assert(currcon->contype == CONSTRAINT_FOREIGN); rel = table_open(currcon->conrelid, lockmode); if (currcon->conenforced != cmdcon->is_enforced) { AlterConstrUpdateConstraintEntry(cmdcon, conrel, contuple); changed = true; } /* Drop triggers */ if (!cmdcon->is_enforced) { /* * When setting a constraint to NOT ENFORCED, the constraint triggers * need to be dropped. Therefore, we must process the child relations * first, followed by the parent, to account for dependencies. */ if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE || get_rel_relkind(currcon->confrelid) == RELKIND_PARTITIONED_TABLE) AlterFKConstrEnforceabilityRecurse(wqueue, cmdcon, conrel, tgrel, fkrelid, pkrelid, contuple, lockmode, InvalidOid, InvalidOid, InvalidOid, InvalidOid); /* Drop all the triggers */ DropForeignKeyConstraintTriggers(tgrel, conoid, InvalidOid, InvalidOid); } else if (changed) /* Create triggers */ { Oid ReferencedDelTriggerOid = InvalidOid, ReferencedUpdTriggerOid = InvalidOid, ReferencingInsTriggerOid = InvalidOid, ReferencingUpdTriggerOid = InvalidOid; /* Prepare the minimal information required for trigger creation. */ Constraint *fkconstraint = makeNode(Constraint); fkconstraint->conname = pstrdup(NameStr(currcon->conname)); fkconstraint->fk_matchtype = currcon->confmatchtype; fkconstraint->fk_upd_action = currcon->confupdtype; fkconstraint->fk_del_action = currcon->confdeltype; fkconstraint->deferrable = currcon->condeferrable; fkconstraint->initdeferred = currcon->condeferred; /* Create referenced triggers */ if (currcon->conrelid == fkrelid) createForeignKeyActionTriggers(currcon->conrelid, currcon->confrelid, fkconstraint, conoid, currcon->conindid, ReferencedParentDelTrigger, ReferencedParentUpdTrigger, &ReferencedDelTriggerOid, &ReferencedUpdTriggerOid); /* Create referencing triggers */ if (currcon->confrelid == pkrelid) createForeignKeyCheckTriggers(currcon->conrelid, pkrelid, fkconstraint, conoid, currcon->conindid, ReferencingParentInsTrigger, ReferencingParentUpdTrigger, &ReferencingInsTriggerOid, &ReferencingUpdTriggerOid); /* * Tell Phase 3 to check that the constraint is satisfied by existing * rows. Only applies to leaf partitions, and (for constraints that * reference a partitioned table) only if this is not one of the * pg_constraint rows that exist solely to support action triggers. */ if (rel->rd_rel->relkind == RELKIND_RELATION && currcon->confrelid == pkrelid) { AlteredTableInfo *tab; NewConstraint *newcon; newcon = palloc0_object(NewConstraint); newcon->name = fkconstraint->conname; newcon->contype = CONSTR_FOREIGN; newcon->refrelid = currcon->confrelid; newcon->refindid = currcon->conindid; newcon->conid = currcon->oid; newcon->qual = (Node *) fkconstraint; /* Find or create work queue entry for this table */ tab = ATGetQueueEntry(wqueue, rel); tab->constraints = lappend(tab->constraints, newcon); } /* * If the table at either end of the constraint is partitioned, we * need to recurse and create triggers for each constraint that is a * child of this one. */ if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE || get_rel_relkind(currcon->confrelid) == RELKIND_PARTITIONED_TABLE) AlterFKConstrEnforceabilityRecurse(wqueue, cmdcon, conrel, tgrel, fkrelid, pkrelid, contuple, lockmode, ReferencedDelTriggerOid, ReferencedUpdTriggerOid, ReferencingInsTriggerOid, ReferencingUpdTriggerOid); } table_close(rel, NoLock); return changed; } /* * Returns true if the CHECK constraint's enforceability is altered. */ static bool ATExecAlterCheckConstrEnforceability(List **wqueue, ATAlterConstraint *cmdcon, Relation conrel, HeapTuple contuple, bool recurse, bool recursing, List *changing_conids, LOCKMODE lockmode) { Form_pg_constraint currcon; Relation rel; bool changed = false; List *children = NIL; bool target_enforced = cmdcon->is_enforced; Oid enforced_parentoid = InvalidOid; /* Since this function recurses, it could be driven to stack overflow */ check_stack_depth(); Assert(cmdcon->alterEnforceability); currcon = (Form_pg_constraint) GETSTRUCT(contuple); Assert(currcon->contype == CONSTRAINT_CHECK); /* * Parent relation already locked by caller, children will be locked by * find_all_inheritors. So NoLock is fine here. */ rel = table_open(currcon->conrelid, NoLock); /* * When setting a constraint to NOT ENFORCED, check whether any matching * parent constraint remains ENFORCED and is not part of this ALTER. * * For a direct ALTER of an inherited constraint, reject the command, * because the child cannot be weakened while its parent remains enforced. * * During recursion, another parent outside this ALTER may still enforce * the same constraint in a regular inheritance hierarchy. In that case, * keep the child constraint ENFORCED so that its merged enforceability * still reflects the remaining enforced parent. Partitions do not need * this recursive parent check because a partition can have only one * direct parent. */ if (!cmdcon->is_enforced && (!recursing || !rel->rd_rel->relispartition) && ATCheckCheckConstrHasEnforcedParent(conrel, rel, contuple, changing_conids, &enforced_parentoid)) { if (!recursing) ereport(ERROR, errcode(ERRCODE_INVALID_OBJECT_DEFINITION), errmsg("cannot mark inherited constraint \"%s\" as %s", NameStr(currcon->conname), "NOT ENFORCED"), errdetail("The matching constraint on parent table \"%s\" is %s.", get_rel_name(enforced_parentoid), "ENFORCED")); target_enforced = true; } /* * Update to the merged enforceability if needed. This may differ from the * requested enforceability when another matching parent constraint * remains enforced. */ if (currcon->conenforced != target_enforced) { ATAlterConstraint updatecon = *cmdcon; updatecon.is_enforced = target_enforced; AlterConstrUpdateConstraintEntry(&updatecon, conrel, contuple); changed = true; } /* * Note that we must recurse even when trying to change a check constraint * to not enforced if it is already not enforced, in case descendant * constraints might be enforced and need to be changed to not enforced, * unless they still inherit an enforced constraint from another parent. * Conversely, we should do nothing if a constraint is being set to * enforced and is already enforced, as descendant constraints cannot be * different in that case. */ if (!cmdcon->is_enforced || changed) { /* * If we're recursing, the parent has already done this, so skip it. * Also, if the constraint is a NO INHERIT constraint, we shouldn't * try to look for it in the children. */ if (!recursing && !currcon->connoinherit) { Assert(changing_conids == NIL); children = find_all_inheritors(RelationGetRelid(rel), lockmode, NULL); /* * When setting NOT ENFORCED, build the set of equivalent CHECK * constraints that this command will attempt to change before * visiting descendants. The root itself has already been checked * above. */ if (!cmdcon->is_enforced) changing_conids = list_make1_oid(currcon->oid); foreach_oid(childoid, children) { if (childoid == RelationGetRelid(rel)) continue; /* * If we are told not to recurse, there had better not be any * child tables, because we can't change constraint * enforceability on the parent unless we have changed * enforceability for all child. */ if (!recurse) ereport(ERROR, errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("constraint must be altered on child tables too"), errhint("Do not specify the ONLY keyword.")); /* * It is sufficient to look up the constraint by name here. * Supported DDL ensures that inheritable CHECK constraints * with the same name have equivalent definitions when they * are propagated to children or when inheritance is * established. All descendants returned by * find_all_inheritors must have this constraint: inherited * CHECK constraints propagate to all children at * inheritance-link creation time and cannot be dropped * independently on child tables. */ if (!cmdcon->is_enforced) changing_conids = list_append_unique_oid(changing_conids, get_relation_constraint_oid(childoid, cmdcon->conname, false)); } } foreach_oid(childoid, children) { if (childoid == RelationGetRelid(rel)) continue; AlterCheckConstrEnforceabilityRecurse(wqueue, cmdcon, conrel, childoid, false, true, changing_conids, lockmode); } } /* * Tell Phase 3 to check that the constraint is satisfied by existing * rows. We only need do this when altering the constraint from NOT * ENFORCED to ENFORCED. */ if (rel->rd_rel->relkind == RELKIND_RELATION && !currcon->conenforced && target_enforced) { AlteredTableInfo *tab; NewConstraint *newcon; Datum val; char *conbin; newcon = palloc0_object(NewConstraint); newcon->name = pstrdup(NameStr(currcon->conname)); newcon->contype = CONSTR_CHECK; val = SysCacheGetAttrNotNull(CONSTROID, contuple, Anum_pg_constraint_conbin); conbin = TextDatumGetCString(val); newcon->qual = expand_generated_columns_in_expr(stringToNode(conbin), rel, 1); /* Find or create work queue entry for this table */ tab = ATGetQueueEntry(wqueue, rel); tab->constraints = lappend(tab->constraints, newcon); } table_close(rel, NoLock); return changed; } /* * Invokes ATExecAlterCheckConstrEnforceability for each CHECK constraint that * is a child of the specified constraint. * * We rely on the parent and child tables having identical CHECK constraint * names to retrieve the child's pg_constraint tuple. * * The arguments to this function have the same meaning as the arguments to * ATExecAlterCheckConstrEnforceability. */ static void AlterCheckConstrEnforceabilityRecurse(List **wqueue, ATAlterConstraint *cmdcon, Relation conrel, Oid conrelid, bool recurse, bool recursing, List *changing_conids, LOCKMODE lockmode) { SysScanDesc pscan; HeapTuple childtup; ScanKeyData skey[3]; ScanKeyInit(&skey[0], Anum_pg_constraint_conrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(conrelid)); ScanKeyInit(&skey[1], Anum_pg_constraint_contypid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(InvalidOid)); ScanKeyInit(&skey[2], Anum_pg_constraint_conname, BTEqualStrategyNumber, F_NAMEEQ, CStringGetDatum(cmdcon->conname)); pscan = systable_beginscan(conrel, ConstraintRelidTypidNameIndexId, true, NULL, 3, skey); if (!HeapTupleIsValid(childtup = systable_getnext(pscan))) ereport(ERROR, errcode(ERRCODE_UNDEFINED_OBJECT), errmsg("constraint \"%s\" of relation \"%s\" does not exist", cmdcon->conname, get_rel_name(conrelid))); ATExecAlterCheckConstrEnforceability(wqueue, cmdcon, conrel, childtup, recurse, recursing, changing_conids, lockmode); systable_endscan(pscan); } /* * When setting an inherited CHECK constraint to NOT ENFORCED, look for a * matching parent constraint that remains ENFORCED and is not part of the same * ALTER. */ static bool ATCheckCheckConstrHasEnforcedParent(Relation conrel, Relation rel, HeapTuple contuple, List *changing_conids, Oid *enforced_parentoid) { Form_pg_constraint currcon; Relation inhrel; SysScanDesc scan; ScanKeyData skey; HeapTuple inheritsTuple; /* Since this function recurses, it could be driven to stack overflow */ check_stack_depth(); currcon = (Form_pg_constraint) GETSTRUCT(contuple); Assert(currcon->contype == CONSTRAINT_CHECK); if (currcon->coninhcount <= 0) return false; inhrel = table_open(InheritsRelationId, AccessShareLock); ScanKeyInit(&skey, Anum_pg_inherits_inhrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(rel))); scan = systable_beginscan(inhrel, InheritsRelidSeqnoIndexId, true, NULL, 1, &skey); while (HeapTupleIsValid(inheritsTuple = systable_getnext(scan))) { Oid parentoid; Relation parentrel = NULL; SysScanDesc pscan; ScanKeyData pkey[3]; HeapTuple parenttup; parentoid = ((Form_pg_inherits) GETSTRUCT(inheritsTuple))->inhparent; ScanKeyInit(&pkey[0], Anum_pg_constraint_conrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(parentoid)); ScanKeyInit(&pkey[1], Anum_pg_constraint_contypid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(InvalidOid)); ScanKeyInit(&pkey[2], Anum_pg_constraint_conname, BTEqualStrategyNumber, F_NAMEEQ, NameGetDatum(&currcon->conname)); pscan = systable_beginscan(conrel, ConstraintRelidTypidNameIndexId, true, NULL, 3, pkey); /* * ConstraintRelidTypidNameIndexId is unique on (conrelid, contypid, * conname), so this loop body executes at most once per parent. */ while (HeapTupleIsValid(parenttup = systable_getnext(pscan))) { Form_pg_constraint parentcon; parentcon = (Form_pg_constraint) GETSTRUCT(parenttup); if (parentcon->contype != CONSTRAINT_CHECK || parentcon->connoinherit || !parentcon->conenforced) continue; if (!constraints_equivalent(parenttup, contuple, RelationGetDescr(conrel))) elog(ERROR, "child table \"%s\" has different definition for check constraint \"%s\"", RelationGetRelationName(rel), NameStr(parentcon->conname)); /* * A parent listed in changing_conids is being changed by the same * ALTER, but it may not have been updated yet. For regular * inheritance, recurse upward to check whether an equivalent * enforced parent outside the ALTER will make it remain enforced. * Partitions cannot have multiple parents, so they do not need * this check. */ if (!rel->rd_rel->relispartition && list_member_oid(changing_conids, parentcon->oid)) { Oid parent_enforced_parentoid = InvalidOid; if (parentrel == NULL) parentrel = table_open(parentoid, NoLock); if (!ATCheckCheckConstrHasEnforcedParent(conrel, parentrel, parenttup, changing_conids, &parent_enforced_parentoid)) continue; } *enforced_parentoid = parentoid; if (parentrel != NULL) table_close(parentrel, NoLock); systable_endscan(pscan); systable_endscan(scan); table_close(inhrel, AccessShareLock); return true; } if (parentrel != NULL) table_close(parentrel, NoLock); systable_endscan(pscan); } systable_endscan(scan); table_close(inhrel, AccessShareLock); return false; } /* * Returns true if the constraint's deferrability is altered. * * *otherrelids is appended OIDs of relations containing affected triggers. * * Note that we must recurse even when the values are correct, in case * indirect descendants have had their constraints altered locally. * (This could be avoided if we forbade altering constraints in partitions * but existing releases don't do that.) */ static bool ATExecAlterConstrDeferrability(List **wqueue, ATAlterConstraint *cmdcon, Relation conrel, Relation tgrel, Relation rel, HeapTuple contuple, bool recurse, List **otherrelids, LOCKMODE lockmode) { Form_pg_constraint currcon; Oid refrelid; bool changed = false; /* since this function recurses, it could be driven to stack overflow */ check_stack_depth(); Assert(cmdcon->alterDeferrability); currcon = (Form_pg_constraint) GETSTRUCT(contuple); refrelid = currcon->confrelid; /* Should be foreign key constraint */ Assert(currcon->contype == CONSTRAINT_FOREIGN); /* * If called to modify a constraint that's already in the desired state, * silently do nothing. */ if (currcon->condeferrable != cmdcon->deferrable || currcon->condeferred != cmdcon->initdeferred) { AlterConstrUpdateConstraintEntry(cmdcon, conrel, contuple); changed = true; /* * Now we need to update the multiple entries in pg_trigger that * implement the constraint. */ AlterConstrTriggerDeferrability(currcon->oid, tgrel, rel, cmdcon->deferrable, cmdcon->initdeferred, otherrelids); } /* * If the table at either end of the constraint is partitioned, we need to * handle every constraint that is a child of this one. */ if (recurse && changed && (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE || get_rel_relkind(refrelid) == RELKIND_PARTITIONED_TABLE)) AlterConstrDeferrabilityRecurse(wqueue, cmdcon, conrel, tgrel, rel, contuple, recurse, otherrelids, lockmode); return changed; } /* * Returns true if the constraint's inheritability is altered. */ static bool ATExecAlterConstrInheritability(List **wqueue, ATAlterConstraint *cmdcon, Relation conrel, Relation rel, HeapTuple contuple, LOCKMODE lockmode) { Form_pg_constraint currcon; AttrNumber colNum; char *colName; List *children; Assert(cmdcon->alterInheritability); currcon = (Form_pg_constraint) GETSTRUCT(contuple); /* The current implementation only works for NOT NULL constraints */ Assert(currcon->contype == CONSTRAINT_NOTNULL); /* * If called to modify a constraint that's already in the desired state, * silently do nothing. */ if (cmdcon->noinherit == currcon->connoinherit) return false; AlterConstrUpdateConstraintEntry(cmdcon, conrel, contuple); CommandCounterIncrement(); /* Fetch the column number and name */ colNum = extractNotNullColumn(contuple); colName = get_attname(currcon->conrelid, colNum, false); /* * Propagate the change to children. For this subcommand type we don't * recursively affect children, just the immediate level. */ children = find_inheritance_children(RelationGetRelid(rel), lockmode); foreach_oid(childoid, children) { ObjectAddress addr; if (cmdcon->noinherit) { HeapTuple childtup; Form_pg_constraint childcon; childtup = findNotNullConstraint(childoid, colName); if (!childtup) elog(ERROR, "cache lookup failed for not-null constraint on column \"%s\" of relation %u", colName, childoid); childcon = (Form_pg_constraint) GETSTRUCT(childtup); Assert(childcon->coninhcount > 0); childcon->coninhcount--; childcon->conislocal = true; CatalogTupleUpdate(conrel, &childtup->t_self, childtup); heap_freetuple(childtup); } else { Relation childrel = table_open(childoid, NoLock); addr = ATExecSetNotNull(wqueue, childrel, NameStr(currcon->conname), colName, true, true, lockmode); if (OidIsValid(addr.objectId)) CommandCounterIncrement(); table_close(childrel, NoLock); } } return true; } /* * A subroutine of ATExecAlterConstrDeferrability that updated constraint * trigger's deferrability. * * The arguments to this function have the same meaning as the arguments to * ATExecAlterConstrDeferrability. */ static void AlterConstrTriggerDeferrability(Oid conoid, Relation tgrel, Relation rel, bool deferrable, bool initdeferred, List **otherrelids) { HeapTuple tgtuple; ScanKeyData tgkey; SysScanDesc tgscan; ScanKeyInit(&tgkey, Anum_pg_trigger_tgconstraint, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(conoid)); tgscan = systable_beginscan(tgrel, TriggerConstraintIndexId, true, NULL, 1, &tgkey); while (HeapTupleIsValid(tgtuple = systable_getnext(tgscan))) { Form_pg_trigger tgform = (Form_pg_trigger) GETSTRUCT(tgtuple); Form_pg_trigger copy_tg; HeapTuple tgCopyTuple; /* * Remember OIDs of other relation(s) involved in FK constraint. * (Note: it's likely that we could skip forcing a relcache inval for * other rels that don't have a trigger whose properties change, but * let's be conservative.) */ if (tgform->tgrelid != RelationGetRelid(rel)) *otherrelids = list_append_unique_oid(*otherrelids, tgform->tgrelid); /* * Update enable status and deferrability of RI_FKey_noaction_del, * RI_FKey_noaction_upd, RI_FKey_check_ins and RI_FKey_check_upd * triggers, but not others; see createForeignKeyActionTriggers and * CreateFKCheckTrigger. */ if (tgform->tgfoid != F_RI_FKEY_NOACTION_DEL && tgform->tgfoid != F_RI_FKEY_NOACTION_UPD && tgform->tgfoid != F_RI_FKEY_CHECK_INS && tgform->tgfoid != F_RI_FKEY_CHECK_UPD) continue; tgCopyTuple = heap_copytuple(tgtuple); copy_tg = (Form_pg_trigger) GETSTRUCT(tgCopyTuple); copy_tg->tgdeferrable = deferrable; copy_tg->tginitdeferred = initdeferred; CatalogTupleUpdate(tgrel, &tgCopyTuple->t_self, tgCopyTuple); InvokeObjectPostAlterHook(TriggerRelationId, tgform->oid, 0); heap_freetuple(tgCopyTuple); } systable_endscan(tgscan); } /* * Invokes ATExecAlterFKConstrEnforceability for each foreign key constraint * that is a child of the specified constraint. * * Note that this doesn't handle recursion the normal way, viz. by scanning the * list of child relations and recursing; instead it uses the conparentid * relationships. This may need to be reconsidered. * * The arguments to this function have the same meaning as the arguments to * ATExecAlterFKConstrEnforceability. */ static void AlterFKConstrEnforceabilityRecurse(List **wqueue, ATAlterConstraint *cmdcon, Relation conrel, Relation tgrel, Oid fkrelid, Oid pkrelid, HeapTuple contuple, LOCKMODE lockmode, Oid ReferencedParentDelTrigger, Oid ReferencedParentUpdTrigger, Oid ReferencingParentInsTrigger, Oid ReferencingParentUpdTrigger) { Form_pg_constraint currcon; Oid conoid; ScanKeyData pkey; SysScanDesc pscan; HeapTuple childtup; currcon = (Form_pg_constraint) GETSTRUCT(contuple); conoid = currcon->oid; ScanKeyInit(&pkey, Anum_pg_constraint_conparentid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(conoid)); pscan = systable_beginscan(conrel, ConstraintParentIndexId, true, NULL, 1, &pkey); while (HeapTupleIsValid(childtup = systable_getnext(pscan))) ATExecAlterFKConstrEnforceability(wqueue, cmdcon, conrel, tgrel, fkrelid, pkrelid, childtup, lockmode, ReferencedParentDelTrigger, ReferencedParentUpdTrigger, ReferencingParentInsTrigger, ReferencingParentUpdTrigger); systable_endscan(pscan); } /* * Invokes ATExecAlterConstrDeferrability for each constraint that is a child of * the specified constraint. * * Note that this doesn't handle recursion the normal way, viz. by scanning the * list of child relations and recursing; instead it uses the conparentid * relationships. This may need to be reconsidered. * * The arguments to this function have the same meaning as the arguments to * ATExecAlterConstrDeferrability. */ static void AlterConstrDeferrabilityRecurse(List **wqueue, ATAlterConstraint *cmdcon, Relation conrel, Relation tgrel, Relation rel, HeapTuple contuple, bool recurse, List **otherrelids, LOCKMODE lockmode) { Form_pg_constraint currcon; Oid conoid; ScanKeyData pkey; SysScanDesc pscan; HeapTuple childtup; currcon = (Form_pg_constraint) GETSTRUCT(contuple); conoid = currcon->oid; ScanKeyInit(&pkey, Anum_pg_constraint_conparentid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(conoid)); pscan = systable_beginscan(conrel, ConstraintParentIndexId, true, NULL, 1, &pkey); while (HeapTupleIsValid(childtup = systable_getnext(pscan))) { Form_pg_constraint childcon = (Form_pg_constraint) GETSTRUCT(childtup); Relation childrel; childrel = table_open(childcon->conrelid, lockmode); ATExecAlterConstrDeferrability(wqueue, cmdcon, conrel, tgrel, childrel, childtup, recurse, otherrelids, lockmode); table_close(childrel, NoLock); } systable_endscan(pscan); } /* * Update the constraint entry for the given ATAlterConstraint command, and * invoke the appropriate hooks. */ static void AlterConstrUpdateConstraintEntry(ATAlterConstraint *cmdcon, Relation conrel, HeapTuple contuple) { HeapTuple copyTuple; Form_pg_constraint copy_con; Assert(cmdcon->alterEnforceability || cmdcon->alterDeferrability || cmdcon->alterInheritability); copyTuple = heap_copytuple(contuple); copy_con = (Form_pg_constraint) GETSTRUCT(copyTuple); if (cmdcon->alterEnforceability) { copy_con->conenforced = cmdcon->is_enforced; /* * NB: The convalidated status is irrelevant when the constraint is * set to NOT ENFORCED, but for consistency, it should still be set * appropriately. Similarly, if the constraint is later changed to * ENFORCED, validation will be performed during phase 3, so it makes * sense to mark it as valid in that case. */ copy_con->convalidated = cmdcon->is_enforced; } if (cmdcon->alterDeferrability) { copy_con->condeferrable = cmdcon->deferrable; copy_con->condeferred = cmdcon->initdeferred; } if (cmdcon->alterInheritability) copy_con->connoinherit = cmdcon->noinherit; CatalogTupleUpdate(conrel, ©Tuple->t_self, copyTuple); InvokeObjectPostAlterHook(ConstraintRelationId, copy_con->oid, 0); /* Make new constraint flags visible to others */ CacheInvalidateRelcacheByRelid(copy_con->conrelid); heap_freetuple(copyTuple); } /* * ALTER TABLE VALIDATE CONSTRAINT * * XXX The reason we handle recursion here rather than at Phase 1 is because * there's no good way to skip recursing when handling foreign keys: there is * no need to lock children in that case, yet we wouldn't be able to avoid * doing so at that level. * * Return value is the address of the validated constraint. If the constraint * was already validated, InvalidObjectAddress is returned. */ static ObjectAddress ATExecValidateConstraint(List **wqueue, Relation rel, char *constrName, bool recurse, bool recursing, LOCKMODE lockmode) { Relation conrel; SysScanDesc scan; ScanKeyData skey[3]; HeapTuple tuple; Form_pg_constraint con; ObjectAddress address; conrel = table_open(ConstraintRelationId, RowExclusiveLock); /* * Find and check the target constraint */ ScanKeyInit(&skey[0], Anum_pg_constraint_conrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(rel))); ScanKeyInit(&skey[1], Anum_pg_constraint_contypid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(InvalidOid)); ScanKeyInit(&skey[2], Anum_pg_constraint_conname, BTEqualStrategyNumber, F_NAMEEQ, CStringGetDatum(constrName)); scan = systable_beginscan(conrel, ConstraintRelidTypidNameIndexId, true, NULL, 3, skey); /* There can be at most one matching row */ if (!HeapTupleIsValid(tuple = systable_getnext(scan))) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_OBJECT), errmsg("constraint \"%s\" of relation \"%s\" does not exist", constrName, RelationGetRelationName(rel)))); con = (Form_pg_constraint) GETSTRUCT(tuple); if (con->contype != CONSTRAINT_FOREIGN && con->contype != CONSTRAINT_CHECK && con->contype != CONSTRAINT_NOTNULL) ereport(ERROR, errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot validate constraint \"%s\" of relation \"%s\"", constrName, RelationGetRelationName(rel)), errdetail("This operation is not supported for this type of constraint.")); if (!con->conenforced) ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("cannot validate NOT ENFORCED constraint"))); if (!con->convalidated) { if (con->contype == CONSTRAINT_FOREIGN) { QueueFKConstraintValidation(wqueue, conrel, rel, con->confrelid, tuple, lockmode); } else if (con->contype == CONSTRAINT_CHECK) { QueueCheckConstraintValidation(wqueue, conrel, rel, constrName, tuple, recurse, recursing, lockmode); } else if (con->contype == CONSTRAINT_NOTNULL) { QueueNNConstraintValidation(wqueue, conrel, rel, tuple, recurse, recursing, lockmode); } ObjectAddressSet(address, ConstraintRelationId, con->oid); } else address = InvalidObjectAddress; /* already validated */ systable_endscan(scan); table_close(conrel, RowExclusiveLock); return address; } /* * QueueFKConstraintValidation * * Add an entry to the wqueue to validate the given foreign key constraint in * Phase 3 and update the convalidated field in the pg_constraint catalog * for the specified relation and all its children. */ static void QueueFKConstraintValidation(List **wqueue, Relation conrel, Relation fkrel, Oid pkrelid, HeapTuple contuple, LOCKMODE lockmode) { Form_pg_constraint con; AlteredTableInfo *tab; HeapTuple copyTuple; Form_pg_constraint copy_con; /* since this function recurses, it could be driven to stack overflow */ check_stack_depth(); con = (Form_pg_constraint) GETSTRUCT(contuple); Assert(con->contype == CONSTRAINT_FOREIGN); Assert(!con->convalidated); /* * Add the validation to phase 3's queue; not needed for partitioned * tables themselves, only for their partitions. * * When the referenced table (pkrelid) is partitioned, the referencing * table (fkrel) has one pg_constraint row pointing to each partition * thereof. These rows are there only to support action triggers and no * table scan is needed, therefore skip this for them as well. */ if (fkrel->rd_rel->relkind == RELKIND_RELATION && con->confrelid == pkrelid) { NewConstraint *newcon; Constraint *fkconstraint; /* Queue validation for phase 3 */ fkconstraint = makeNode(Constraint); /* for now this is all we need */ fkconstraint->conname = pstrdup(NameStr(con->conname)); newcon = palloc0_object(NewConstraint); newcon->name = fkconstraint->conname; newcon->contype = CONSTR_FOREIGN; newcon->refrelid = con->confrelid; newcon->refindid = con->conindid; newcon->conid = con->oid; newcon->qual = (Node *) fkconstraint; /* Find or create work queue entry for this table */ tab = ATGetQueueEntry(wqueue, fkrel); tab->constraints = lappend(tab->constraints, newcon); } /* * If the table at either end of the constraint is partitioned, we need to * recurse and handle every unvalidated constraint that is a child of this * constraint. */ if (fkrel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE || get_rel_relkind(con->confrelid) == RELKIND_PARTITIONED_TABLE) { ScanKeyData pkey; SysScanDesc pscan; HeapTuple childtup; ScanKeyInit(&pkey, Anum_pg_constraint_conparentid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(con->oid)); pscan = systable_beginscan(conrel, ConstraintParentIndexId, true, NULL, 1, &pkey); while (HeapTupleIsValid(childtup = systable_getnext(pscan))) { Form_pg_constraint childcon; Relation childrel; childcon = (Form_pg_constraint) GETSTRUCT(childtup); /* * If the child constraint has already been validated, no further * action is required for it or its descendants, as they are all * valid. */ if (childcon->convalidated) continue; childrel = table_open(childcon->conrelid, lockmode); /* * NB: Note that pkrelid should be passed as-is during recursion, * as it is required to identify the root referenced table. */ QueueFKConstraintValidation(wqueue, conrel, childrel, pkrelid, childtup, lockmode); table_close(childrel, NoLock); } systable_endscan(pscan); } /* * Now mark the pg_constraint row as validated (even if we didn't check, * notably the ones for partitions on the referenced side). * * We rely on transaction abort to roll back this change if phase 3 * ultimately finds violating rows. This is a bit ugly. */ copyTuple = heap_copytuple(contuple); copy_con = (Form_pg_constraint) GETSTRUCT(copyTuple); copy_con->convalidated = true; CatalogTupleUpdate(conrel, ©Tuple->t_self, copyTuple); InvokeObjectPostAlterHook(ConstraintRelationId, con->oid, 0); heap_freetuple(copyTuple); } /* * QueueCheckConstraintValidation * * Add an entry to the wqueue to validate the given check constraint in Phase 3 * and update the convalidated field in the pg_constraint catalog for the * specified relation and all its inheriting children. */ static void QueueCheckConstraintValidation(List **wqueue, Relation conrel, Relation rel, char *constrName, HeapTuple contuple, bool recurse, bool recursing, LOCKMODE lockmode) { Form_pg_constraint con; AlteredTableInfo *tab; HeapTuple copyTuple; Form_pg_constraint copy_con; List *children = NIL; ListCell *child; NewConstraint *newcon; Datum val; char *conbin; con = (Form_pg_constraint) GETSTRUCT(contuple); Assert(con->contype == CONSTRAINT_CHECK); /* * If we're recursing, the parent has already done this, so skip it. Also, * if the constraint is a NO INHERIT constraint, we shouldn't try to look * for it in the children. */ if (!recursing && !con->connoinherit) children = find_all_inheritors(RelationGetRelid(rel), lockmode, NULL); /* * For CHECK constraints, we must ensure that we only mark the constraint * as validated on the parent if it's already validated on the children. * * We recurse before validating on the parent, to reduce risk of * deadlocks. */ foreach(child, children) { Oid childoid = lfirst_oid(child); Relation childrel; if (childoid == RelationGetRelid(rel)) continue; /* * If we are told not to recurse, there had better not be any child * tables, because we can't mark the constraint on the parent valid * unless it is valid for all child tables. */ if (!recurse) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("constraint must be validated on child tables too"))); /* find_all_inheritors already got lock */ childrel = table_open(childoid, NoLock); ATExecValidateConstraint(wqueue, childrel, constrName, false, true, lockmode); table_close(childrel, NoLock); } /* Queue validation for phase 3 */ newcon = palloc0_object(NewConstraint); newcon->name = constrName; newcon->contype = CONSTR_CHECK; newcon->refrelid = InvalidOid; newcon->refindid = InvalidOid; newcon->conid = con->oid; val = SysCacheGetAttrNotNull(CONSTROID, contuple, Anum_pg_constraint_conbin); conbin = TextDatumGetCString(val); newcon->qual = expand_generated_columns_in_expr(stringToNode(conbin), rel, 1); /* Find or create work queue entry for this table */ tab = ATGetQueueEntry(wqueue, rel); tab->constraints = lappend(tab->constraints, newcon); /* * Invalidate relcache so that others see the new validated constraint. */ CacheInvalidateRelcache(rel); /* * Now update the catalog, while we have the door open. */ copyTuple = heap_copytuple(contuple); copy_con = (Form_pg_constraint) GETSTRUCT(copyTuple); copy_con->convalidated = true; CatalogTupleUpdate(conrel, ©Tuple->t_self, copyTuple); InvokeObjectPostAlterHook(ConstraintRelationId, con->oid, 0); heap_freetuple(copyTuple); } /* * QueueNNConstraintValidation * * Add an entry to the wqueue to validate the given not-null constraint in * Phase 3 and update the convalidated field in the pg_constraint catalog for * the specified relation and all its inheriting children. */ static void QueueNNConstraintValidation(List **wqueue, Relation conrel, Relation rel, HeapTuple contuple, bool recurse, bool recursing, LOCKMODE lockmode) { Form_pg_constraint con; AlteredTableInfo *tab; HeapTuple copyTuple; Form_pg_constraint copy_con; List *children = NIL; AttrNumber attnum; char *colname; con = (Form_pg_constraint) GETSTRUCT(contuple); Assert(con->contype == CONSTRAINT_NOTNULL); attnum = extractNotNullColumn(contuple); /* * If we're recursing, we've already done this for parent, so skip it. * Also, if the constraint is a NO INHERIT constraint, we shouldn't try to * look for it in the children. * * We recurse before validating on the parent, to reduce risk of * deadlocks. */ if (!recursing && !con->connoinherit) children = find_all_inheritors(RelationGetRelid(rel), lockmode, NULL); colname = get_attname(RelationGetRelid(rel), attnum, false); foreach_oid(childoid, children) { Relation childrel; HeapTuple contup; Form_pg_constraint childcon; char *conname; if (childoid == RelationGetRelid(rel)) continue; /* * If we are told not to recurse, there had better not be any child * tables, because we can't mark the constraint on the parent valid * unless it is valid for all child tables. */ if (!recurse) ereport(ERROR, errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("constraint must be validated on child tables too")); /* * The column on child might have a different attnum, so search by * column name. */ contup = findNotNullConstraint(childoid, colname); if (!contup) elog(ERROR, "cache lookup failed for not-null constraint on column \"%s\" of relation \"%s\"", colname, get_rel_name(childoid)); childcon = (Form_pg_constraint) GETSTRUCT(contup); if (childcon->convalidated) continue; /* find_all_inheritors already got lock */ childrel = table_open(childoid, NoLock); conname = pstrdup(NameStr(childcon->conname)); /* XXX improve ATExecValidateConstraint API to avoid double search */ ATExecValidateConstraint(wqueue, childrel, conname, false, true, lockmode); table_close(childrel, NoLock); } /* Set attnotnull appropriately without queueing another validation */ set_attnotnull(NULL, rel, attnum, false); tab = ATGetQueueEntry(wqueue, rel); tab->verify_new_notnull = true; /* * Invalidate relcache so that others see the new validated constraint. */ CacheInvalidateRelcache(rel); /* * Now update the catalogs, while we have the door open. */ copyTuple = heap_copytuple(contuple); copy_con = (Form_pg_constraint) GETSTRUCT(copyTuple); copy_con->convalidated = true; CatalogTupleUpdate(conrel, ©Tuple->t_self, copyTuple); InvokeObjectPostAlterHook(ConstraintRelationId, con->oid, 0); heap_freetuple(copyTuple); } /* * transformColumnNameList - transform list of column names * * Lookup each name and return its attnum and, optionally, type and collation * OIDs * * Note: the name of this function suggests that it's general-purpose, * but actually it's only used to look up names appearing in foreign-key * clauses. The error messages would need work to use it in other cases, * and perhaps the validity checks as well. */ static int transformColumnNameList(Oid relId, List *colList, int16 *attnums, Oid *atttypids, Oid *attcollids) { ListCell *l; int attnum; attnum = 0; foreach(l, colList) { char *attname = strVal(lfirst(l)); HeapTuple atttuple; Form_pg_attribute attform; atttuple = SearchSysCacheAttName(relId, attname); if (!HeapTupleIsValid(atttuple)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" referenced in foreign key constraint does not exist", attname))); attform = (Form_pg_attribute) GETSTRUCT(atttuple); if (attform->attnum < 0) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("system columns cannot be used in foreign keys"))); if (attnum >= INDEX_MAX_KEYS) ereport(ERROR, (errcode(ERRCODE_TOO_MANY_COLUMNS), errmsg("cannot have more than %d keys in a foreign key", INDEX_MAX_KEYS))); attnums[attnum] = attform->attnum; if (atttypids != NULL) atttypids[attnum] = attform->atttypid; if (attcollids != NULL) attcollids[attnum] = attform->attcollation; ReleaseSysCache(atttuple); attnum++; } return attnum; } /* * transformFkeyGetPrimaryKey - * * Look up the names, attnums, types, and collations of the primary key attributes * for the pkrel. Also return the index OID and index opclasses of the * index supporting the primary key. Also return whether the index has * WITHOUT OVERLAPS. * * All parameters except pkrel are output parameters. Also, the function * return value is the number of attributes in the primary key. * * Used when the column list in the REFERENCES specification is omitted. */ static int transformFkeyGetPrimaryKey(Relation pkrel, Oid *indexOid, List **attnamelist, int16 *attnums, Oid *atttypids, Oid *attcollids, Oid *opclasses, bool *pk_has_without_overlaps) { List *indexoidlist; ListCell *indexoidscan; HeapTuple indexTuple = NULL; Form_pg_index indexStruct = NULL; Datum indclassDatum; oidvector *indclass; int i; /* * Get the list of index OIDs for the table from the relcache, and look up * each one in the pg_index syscache until we find one marked primary key * (hopefully there isn't more than one such). Insist it's valid, too. */ *indexOid = InvalidOid; indexoidlist = RelationGetIndexList(pkrel); foreach(indexoidscan, indexoidlist) { Oid indexoid = lfirst_oid(indexoidscan); indexTuple = SearchSysCache1(INDEXRELID, ObjectIdGetDatum(indexoid)); if (!HeapTupleIsValid(indexTuple)) elog(ERROR, "cache lookup failed for index %u", indexoid); indexStruct = (Form_pg_index) GETSTRUCT(indexTuple); if (indexStruct->indisprimary && indexStruct->indisvalid) { /* * Refuse to use a deferrable primary key. This is per SQL spec, * and there would be a lot of interesting semantic problems if we * tried to allow it. */ if (!indexStruct->indimmediate) ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("cannot use a deferrable primary key for referenced table \"%s\"", RelationGetRelationName(pkrel)))); *indexOid = indexoid; break; } ReleaseSysCache(indexTuple); } list_free(indexoidlist); /* * Check that we found it */ if (!OidIsValid(*indexOid)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_OBJECT), errmsg("there is no primary key for referenced table \"%s\"", RelationGetRelationName(pkrel)))); /* Must get indclass the hard way */ indclassDatum = SysCacheGetAttrNotNull(INDEXRELID, indexTuple, Anum_pg_index_indclass); indclass = (oidvector *) DatumGetPointer(indclassDatum); /* * Now build the list of PK attributes from the indkey definition (we * assume a primary key cannot have expressional elements) */ *attnamelist = NIL; for (i = 0; i < indexStruct->indnkeyatts; i++) { int pkattno = indexStruct->indkey.values[i]; attnums[i] = pkattno; atttypids[i] = attnumTypeId(pkrel, pkattno); attcollids[i] = attnumCollationId(pkrel, pkattno); opclasses[i] = indclass->values[i]; *attnamelist = lappend(*attnamelist, makeString(pstrdup(NameStr(*attnumAttName(pkrel, pkattno))))); } *pk_has_without_overlaps = indexStruct->indisexclusion; ReleaseSysCache(indexTuple); return i; } /* * transformFkeyCheckAttrs - * * Validate that the 'attnums' columns in the 'pkrel' relation are valid to * reference as part of a foreign key constraint. * * Returns the OID of the unique index supporting the constraint and * populates the caller-provided 'opclasses' array with the opclasses * associated with the index columns. Also sets whether the index * uses WITHOUT OVERLAPS. * * Raises an ERROR on validation failure. */ static Oid transformFkeyCheckAttrs(Relation pkrel, int numattrs, int16 *attnums, bool with_period, Oid *opclasses, bool *pk_has_without_overlaps) { Oid indexoid = InvalidOid; bool found = false; bool found_deferrable = false; List *indexoidlist; ListCell *indexoidscan; int i, j; /* * Reject duplicate appearances of columns in the referenced-columns list. * Such a case is forbidden by the SQL standard, and even if we thought it * useful to allow it, there would be ambiguity about how to match the * list to unique indexes (in particular, it'd be unclear which index * opclass goes with which FK column). */ for (i = 0; i < numattrs; i++) { for (j = i + 1; j < numattrs; j++) { if (attnums[i] == attnums[j]) ereport(ERROR, (errcode(ERRCODE_INVALID_FOREIGN_KEY), errmsg("foreign key referenced-columns list must not contain duplicates"))); } } /* * Get the list of index OIDs for the table from the relcache, and look up * each one in the pg_index syscache, and match unique indexes to the list * of attnums we are given. */ indexoidlist = RelationGetIndexList(pkrel); foreach(indexoidscan, indexoidlist) { HeapTuple indexTuple; Form_pg_index indexStruct; indexoid = lfirst_oid(indexoidscan); indexTuple = SearchSysCache1(INDEXRELID, ObjectIdGetDatum(indexoid)); if (!HeapTupleIsValid(indexTuple)) elog(ERROR, "cache lookup failed for index %u", indexoid); indexStruct = (Form_pg_index) GETSTRUCT(indexTuple); /* * Must have the right number of columns; must be unique (or if * temporal then exclusion instead) and not a partial index; forget it * if there are any expressions, too. Invalid indexes are out as well. */ if (indexStruct->indnkeyatts == numattrs && (with_period ? indexStruct->indisexclusion : indexStruct->indisunique) && indexStruct->indisvalid && heap_attisnull(indexTuple, Anum_pg_index_indpred, NULL) && heap_attisnull(indexTuple, Anum_pg_index_indexprs, NULL)) { Datum indclassDatum; oidvector *indclass; /* Must get indclass the hard way */ indclassDatum = SysCacheGetAttrNotNull(INDEXRELID, indexTuple, Anum_pg_index_indclass); indclass = (oidvector *) DatumGetPointer(indclassDatum); /* * The given attnum list may match the index columns in any order. * Check for a match, and extract the appropriate opclasses while * we're at it. * * We know that attnums[] is duplicate-free per the test at the * start of this function, and we checked above that the number of * index columns agrees, so if we find a match for each attnums[] * entry then we must have a one-to-one match in some order. */ for (i = 0; i < numattrs; i++) { found = false; for (j = 0; j < numattrs; j++) { if (attnums[i] == indexStruct->indkey.values[j]) { opclasses[i] = indclass->values[j]; found = true; break; } } if (!found) break; } /* The last attribute in the index must be the PERIOD FK part */ if (found && with_period) { int16 periodattnum = attnums[numattrs - 1]; found = (periodattnum == indexStruct->indkey.values[numattrs - 1]); } /* * Refuse to use a deferrable unique/primary key. This is per SQL * spec, and there would be a lot of interesting semantic problems * if we tried to allow it. */ if (found && !indexStruct->indimmediate) { /* * Remember that we found an otherwise matching index, so that * we can generate a more appropriate error message. */ found_deferrable = true; found = false; } /* We need to know whether the index has WITHOUT OVERLAPS */ if (found) *pk_has_without_overlaps = indexStruct->indisexclusion; } ReleaseSysCache(indexTuple); if (found) break; } if (!found) { if (found_deferrable) ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("cannot use a deferrable unique constraint for referenced table \"%s\"", RelationGetRelationName(pkrel)))); else ereport(ERROR, (errcode(ERRCODE_INVALID_FOREIGN_KEY), errmsg("there is no unique constraint matching given keys for referenced table \"%s\"", RelationGetRelationName(pkrel)))); } list_free(indexoidlist); return indexoid; } /* * findFkeyCast - * * Wrapper around find_coercion_pathway() for ATAddForeignKeyConstraint(). * Caller has equal regard for binary coercibility and for an exact match. */ static CoercionPathType findFkeyCast(Oid targetTypeId, Oid sourceTypeId, Oid *funcid) { CoercionPathType ret; if (targetTypeId == sourceTypeId) { ret = COERCION_PATH_RELABELTYPE; *funcid = InvalidOid; } else { ret = find_coercion_pathway(targetTypeId, sourceTypeId, COERCION_IMPLICIT, funcid); if (ret == COERCION_PATH_NONE) /* A previously-relied-upon cast is now gone. */ elog(ERROR, "could not find cast from %u to %u", sourceTypeId, targetTypeId); } return ret; } /* * Permissions checks on the referenced table for ADD FOREIGN KEY * * Note: we have already checked that the user owns the referencing table, * else we'd have failed much earlier; no additional checks are needed for it. */ static void checkFkeyPermissions(Relation rel, int16 *attnums, int natts) { Oid roleid = GetUserId(); AclResult aclresult; int i; /* Okay if we have relation-level REFERENCES permission */ aclresult = pg_class_aclcheck(RelationGetRelid(rel), roleid, ACL_REFERENCES); if (aclresult == ACLCHECK_OK) return; /* Else we must have REFERENCES on each column */ for (i = 0; i < natts; i++) { aclresult = pg_attribute_aclcheck(RelationGetRelid(rel), attnums[i], roleid, ACL_REFERENCES); if (aclresult != ACLCHECK_OK) aclcheck_error(aclresult, get_relkind_objtype(rel->rd_rel->relkind), RelationGetRelationName(rel)); } } /* * Scan the existing rows in a table to verify they meet a proposed FK * constraint. * * Caller must have opened and locked both relations appropriately. */ static void validateForeignKeyConstraint(char *conname, Relation rel, Relation pkrel, Oid pkindOid, Oid constraintOid, bool hasperiod) { TupleTableSlot *slot; TableScanDesc scan; Trigger trig = {0}; Snapshot snapshot; MemoryContext oldcxt; MemoryContext perTupCxt; ereport(DEBUG1, (errmsg_internal("validating foreign key constraint \"%s\"", conname))); /* * Build a trigger call structure; we'll need it either way. */ trig.tgoid = InvalidOid; trig.tgname = conname; trig.tgenabled = TRIGGER_FIRES_ON_ORIGIN; trig.tgisinternal = true; trig.tgconstrrelid = RelationGetRelid(pkrel); trig.tgconstrindid = pkindOid; trig.tgconstraint = constraintOid; trig.tgdeferrable = false; trig.tginitdeferred = false; /* we needn't fill in remaining fields */ /* * See if we can do it with a single LEFT JOIN query. A false result * indicates we must proceed with the fire-the-trigger method. We can't do * a LEFT JOIN for temporal FKs yet, but we can once we support temporal * left joins. */ if (!hasperiod && RI_Initial_Check(&trig, rel, pkrel)) return; /* * Scan through each tuple, calling RI_FKey_check_ins (insert trigger) as * if that tuple had just been inserted. If any of those fail, it should * ereport(ERROR) and that's that. */ snapshot = RegisterSnapshot(GetLatestSnapshot()); slot = table_slot_create(rel, NULL); scan = table_beginscan(rel, snapshot, 0, NULL, SO_NONE); perTupCxt = AllocSetContextCreate(CurrentMemoryContext, "validateForeignKeyConstraint", ALLOCSET_SMALL_SIZES); oldcxt = MemoryContextSwitchTo(perTupCxt); while (table_scan_getnextslot(scan, ForwardScanDirection, slot)) { LOCAL_FCINFO(fcinfo, 0); TriggerData trigdata = {0}; CHECK_FOR_INTERRUPTS(); /* * Make a call to the trigger function * * No parameters are passed, but we do set a context */ MemSet(fcinfo, 0, SizeForFunctionCallInfo(0)); /* * We assume RI_FKey_check_ins won't look at flinfo... */ trigdata.type = T_TriggerData; trigdata.tg_event = TRIGGER_EVENT_INSERT | TRIGGER_EVENT_ROW; trigdata.tg_relation = rel; trigdata.tg_trigtuple = ExecFetchSlotHeapTuple(slot, false, NULL); trigdata.tg_trigslot = slot; trigdata.tg_trigger = &trig; fcinfo->context = (Node *) &trigdata; RI_FKey_check_ins(fcinfo); MemoryContextReset(perTupCxt); } MemoryContextSwitchTo(oldcxt); MemoryContextDelete(perTupCxt); table_endscan(scan); UnregisterSnapshot(snapshot); ExecDropSingleTupleTableSlot(slot); } /* * CreateFKCheckTrigger * Creates the insert (on_insert=true) or update "check" trigger that * implements a given foreign key * * Returns the OID of the so created trigger. */ static Oid CreateFKCheckTrigger(Oid myRelOid, Oid refRelOid, Constraint *fkconstraint, Oid constraintOid, Oid indexOid, Oid parentTrigOid, bool on_insert) { ObjectAddress trigAddress; CreateTrigStmt *fk_trigger; /* * Note: for a self-referential FK (referencing and referenced tables are * the same), it is important that the ON UPDATE action fires before the * CHECK action, since both triggers will fire on the same row during an * UPDATE event; otherwise the CHECK trigger will be checking a non-final * state of the row. Triggers fire in name order, so we ensure this by * using names like "RI_ConstraintTrigger_a_NNNN" for the action triggers * and "RI_ConstraintTrigger_c_NNNN" for the check triggers. */ fk_trigger = makeNode(CreateTrigStmt); fk_trigger->replace = false; fk_trigger->isconstraint = true; fk_trigger->trigname = "RI_ConstraintTrigger_c"; fk_trigger->relation = NULL; /* Either ON INSERT or ON UPDATE */ if (on_insert) { fk_trigger->funcname = SystemFuncName("RI_FKey_check_ins"); fk_trigger->events = TRIGGER_TYPE_INSERT; } else { fk_trigger->funcname = SystemFuncName("RI_FKey_check_upd"); fk_trigger->events = TRIGGER_TYPE_UPDATE; } fk_trigger->args = NIL; fk_trigger->row = true; fk_trigger->timing = TRIGGER_TYPE_AFTER; fk_trigger->columns = NIL; fk_trigger->whenClause = NULL; fk_trigger->transitionRels = NIL; fk_trigger->deferrable = fkconstraint->deferrable; fk_trigger->initdeferred = fkconstraint->initdeferred; fk_trigger->constrrel = NULL; trigAddress = CreateTrigger(fk_trigger, NULL, myRelOid, refRelOid, constraintOid, indexOid, InvalidOid, parentTrigOid, NULL, true, false); /* Make changes-so-far visible */ CommandCounterIncrement(); return trigAddress.objectId; } /* * createForeignKeyActionTriggers * Create the referenced-side "action" triggers that implement a foreign * key. * * Returns the OIDs of the so created triggers in *deleteTrigOid and * *updateTrigOid. */ static void createForeignKeyActionTriggers(Oid myRelOid, Oid refRelOid, Constraint *fkconstraint, Oid constraintOid, Oid indexOid, Oid parentDelTrigger, Oid parentUpdTrigger, Oid *deleteTrigOid, Oid *updateTrigOid) { CreateTrigStmt *fk_trigger; ObjectAddress trigAddress; /* * Build and execute a CREATE CONSTRAINT TRIGGER statement for the ON * DELETE action on the referenced table. */ fk_trigger = makeNode(CreateTrigStmt); fk_trigger->replace = false; fk_trigger->isconstraint = true; fk_trigger->trigname = "RI_ConstraintTrigger_a"; fk_trigger->relation = NULL; fk_trigger->args = NIL; fk_trigger->row = true; fk_trigger->timing = TRIGGER_TYPE_AFTER; fk_trigger->events = TRIGGER_TYPE_DELETE; fk_trigger->columns = NIL; fk_trigger->whenClause = NULL; fk_trigger->transitionRels = NIL; fk_trigger->constrrel = NULL; switch (fkconstraint->fk_del_action) { case FKCONSTR_ACTION_NOACTION: fk_trigger->deferrable = fkconstraint->deferrable; fk_trigger->initdeferred = fkconstraint->initdeferred; fk_trigger->funcname = SystemFuncName("RI_FKey_noaction_del"); break; case FKCONSTR_ACTION_RESTRICT: fk_trigger->deferrable = false; fk_trigger->initdeferred = false; fk_trigger->funcname = SystemFuncName("RI_FKey_restrict_del"); break; case FKCONSTR_ACTION_CASCADE: fk_trigger->deferrable = false; fk_trigger->initdeferred = false; fk_trigger->funcname = SystemFuncName("RI_FKey_cascade_del"); break; case FKCONSTR_ACTION_SETNULL: fk_trigger->deferrable = false; fk_trigger->initdeferred = false; fk_trigger->funcname = SystemFuncName("RI_FKey_setnull_del"); break; case FKCONSTR_ACTION_SETDEFAULT: fk_trigger->deferrable = false; fk_trigger->initdeferred = false; fk_trigger->funcname = SystemFuncName("RI_FKey_setdefault_del"); break; default: elog(ERROR, "unrecognized FK action type: %d", (int) fkconstraint->fk_del_action); break; } trigAddress = CreateTrigger(fk_trigger, NULL, refRelOid, myRelOid, constraintOid, indexOid, InvalidOid, parentDelTrigger, NULL, true, false); if (deleteTrigOid) *deleteTrigOid = trigAddress.objectId; /* Make changes-so-far visible */ CommandCounterIncrement(); /* * Build and execute a CREATE CONSTRAINT TRIGGER statement for the ON * UPDATE action on the referenced table. */ fk_trigger = makeNode(CreateTrigStmt); fk_trigger->replace = false; fk_trigger->isconstraint = true; fk_trigger->trigname = "RI_ConstraintTrigger_a"; fk_trigger->relation = NULL; fk_trigger->args = NIL; fk_trigger->row = true; fk_trigger->timing = TRIGGER_TYPE_AFTER; fk_trigger->events = TRIGGER_TYPE_UPDATE; fk_trigger->columns = NIL; fk_trigger->whenClause = NULL; fk_trigger->transitionRels = NIL; fk_trigger->constrrel = NULL; switch (fkconstraint->fk_upd_action) { case FKCONSTR_ACTION_NOACTION: fk_trigger->deferrable = fkconstraint->deferrable; fk_trigger->initdeferred = fkconstraint->initdeferred; fk_trigger->funcname = SystemFuncName("RI_FKey_noaction_upd"); break; case FKCONSTR_ACTION_RESTRICT: fk_trigger->deferrable = false; fk_trigger->initdeferred = false; fk_trigger->funcname = SystemFuncName("RI_FKey_restrict_upd"); break; case FKCONSTR_ACTION_CASCADE: fk_trigger->deferrable = false; fk_trigger->initdeferred = false; fk_trigger->funcname = SystemFuncName("RI_FKey_cascade_upd"); break; case FKCONSTR_ACTION_SETNULL: fk_trigger->deferrable = false; fk_trigger->initdeferred = false; fk_trigger->funcname = SystemFuncName("RI_FKey_setnull_upd"); break; case FKCONSTR_ACTION_SETDEFAULT: fk_trigger->deferrable = false; fk_trigger->initdeferred = false; fk_trigger->funcname = SystemFuncName("RI_FKey_setdefault_upd"); break; default: elog(ERROR, "unrecognized FK action type: %d", (int) fkconstraint->fk_upd_action); break; } trigAddress = CreateTrigger(fk_trigger, NULL, refRelOid, myRelOid, constraintOid, indexOid, InvalidOid, parentUpdTrigger, NULL, true, false); if (updateTrigOid) *updateTrigOid = trigAddress.objectId; } /* * createForeignKeyCheckTriggers * Create the referencing-side "check" triggers that implement a foreign * key. * * Returns the OIDs of the so created triggers in *insertTrigOid and * *updateTrigOid. */ static void createForeignKeyCheckTriggers(Oid myRelOid, Oid refRelOid, Constraint *fkconstraint, Oid constraintOid, Oid indexOid, Oid parentInsTrigger, Oid parentUpdTrigger, Oid *insertTrigOid, Oid *updateTrigOid) { *insertTrigOid = CreateFKCheckTrigger(myRelOid, refRelOid, fkconstraint, constraintOid, indexOid, parentInsTrigger, true); *updateTrigOid = CreateFKCheckTrigger(myRelOid, refRelOid, fkconstraint, constraintOid, indexOid, parentUpdTrigger, false); } /* * ALTER TABLE DROP CONSTRAINT * * Like DROP COLUMN, we can't use the normal ALTER TABLE recursion mechanism. */ static void ATExecDropConstraint(Relation rel, const char *constrName, DropBehavior behavior, bool recurse, bool missing_ok, LOCKMODE lockmode) { Relation conrel; SysScanDesc scan; ScanKeyData skey[3]; HeapTuple tuple; bool found = false; conrel = table_open(ConstraintRelationId, RowExclusiveLock); /* * Find and drop the target constraint */ ScanKeyInit(&skey[0], Anum_pg_constraint_conrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(rel))); ScanKeyInit(&skey[1], Anum_pg_constraint_contypid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(InvalidOid)); ScanKeyInit(&skey[2], Anum_pg_constraint_conname, BTEqualStrategyNumber, F_NAMEEQ, CStringGetDatum(constrName)); scan = systable_beginscan(conrel, ConstraintRelidTypidNameIndexId, true, NULL, 3, skey); /* There can be at most one matching row */ if (HeapTupleIsValid(tuple = systable_getnext(scan))) { dropconstraint_internal(rel, tuple, behavior, recurse, false, missing_ok, lockmode); found = true; } systable_endscan(scan); if (!found) { if (!missing_ok) ereport(ERROR, errcode(ERRCODE_UNDEFINED_OBJECT), errmsg("constraint \"%s\" of relation \"%s\" does not exist", constrName, RelationGetRelationName(rel))); else ereport(NOTICE, errmsg("constraint \"%s\" of relation \"%s\" does not exist, skipping", constrName, RelationGetRelationName(rel))); } table_close(conrel, RowExclusiveLock); } /* * Remove a constraint, using its pg_constraint tuple * * Implementation for ALTER TABLE DROP CONSTRAINT and ALTER TABLE ALTER COLUMN * DROP NOT NULL. * * Returns the address of the constraint being removed. */ static ObjectAddress dropconstraint_internal(Relation rel, HeapTuple constraintTup, DropBehavior behavior, bool recurse, bool recursing, bool missing_ok, LOCKMODE lockmode) { Relation conrel; Form_pg_constraint con; ObjectAddress conobj; List *children; bool is_no_inherit_constraint = false; char *constrName; char *colname = NULL; /* Guard against stack overflow due to overly deep inheritance tree. */ check_stack_depth(); /* At top level, permission check was done in ATPrepCmd, else do it */ if (recursing) ATSimplePermissions(AT_DropConstraint, rel, ATT_TABLE | ATT_PARTITIONED_TABLE | ATT_FOREIGN_TABLE); conrel = table_open(ConstraintRelationId, RowExclusiveLock); con = (Form_pg_constraint) GETSTRUCT(constraintTup); constrName = NameStr(con->conname); /* Don't allow drop of inherited constraints */ if (con->coninhcount > 0 && !recursing) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("cannot drop inherited constraint \"%s\" of relation \"%s\"", constrName, RelationGetRelationName(rel)))); /* * Reset pg_constraint.attnotnull, if this is a not-null constraint. * * While doing that, we're in a good position to disallow dropping a not- * null constraint underneath a primary key, a replica identity index, or * a generated identity column. */ if (con->contype == CONSTRAINT_NOTNULL) { Relation attrel = table_open(AttributeRelationId, RowExclusiveLock); AttrNumber attnum = extractNotNullColumn(constraintTup); Bitmapset *pkattrs; Bitmapset *irattrs; HeapTuple atttup; Form_pg_attribute attForm; /* save column name for recursion step */ colname = get_attname(RelationGetRelid(rel), attnum, false); /* * Disallow if it's in the primary key. For partitioned tables we * cannot rely solely on RelationGetIndexAttrBitmap, because it'll * return NULL if the primary key is invalid; but we still need to * protect not-null constraints under such a constraint, so check the * slow way. */ pkattrs = RelationGetIndexAttrBitmap(rel, INDEX_ATTR_BITMAP_PRIMARY_KEY); if (pkattrs == NULL && rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) { Oid pkindex = RelationGetPrimaryKeyIndex(rel, true); if (OidIsValid(pkindex)) { Relation pk = relation_open(pkindex, AccessShareLock); pkattrs = NULL; for (int i = 0; i < pk->rd_index->indnkeyatts; i++) pkattrs = bms_add_member(pkattrs, pk->rd_index->indkey.values[i]); relation_close(pk, AccessShareLock); } } if (pkattrs && bms_is_member(attnum - FirstLowInvalidHeapAttributeNumber, pkattrs)) ereport(ERROR, errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("column \"%s\" is in a primary key", get_attname(RelationGetRelid(rel), attnum, false))); /* Disallow if it's in the replica identity */ irattrs = RelationGetIndexAttrBitmap(rel, INDEX_ATTR_BITMAP_IDENTITY_KEY); if (bms_is_member(attnum - FirstLowInvalidHeapAttributeNumber, irattrs)) ereport(ERROR, errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("column \"%s\" is in index used as replica identity", get_attname(RelationGetRelid(rel), attnum, false))); /* Disallow if it's a GENERATED AS IDENTITY column */ atttup = SearchSysCacheCopyAttNum(RelationGetRelid(rel), attnum); if (!HeapTupleIsValid(atttup)) elog(ERROR, "cache lookup failed for attribute %d of relation %u", attnum, RelationGetRelid(rel)); attForm = (Form_pg_attribute) GETSTRUCT(atttup); if (attForm->attidentity != '\0') ereport(ERROR, errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("column \"%s\" of relation \"%s\" is an identity column", get_attname(RelationGetRelid(rel), attnum, false), RelationGetRelationName(rel))); /* All good -- reset attnotnull if needed */ if (attForm->attnotnull) { attForm->attnotnull = false; CatalogTupleUpdate(attrel, &atttup->t_self, atttup); } table_close(attrel, RowExclusiveLock); } is_no_inherit_constraint = con->connoinherit; /* * If it's a foreign-key constraint, we'd better lock the referenced table * and check that that's not in use, just as we've already done for the * constrained table (else we might, eg, be dropping a trigger that has * unfired events). But we can/must skip that in the self-referential * case. */ if (con->contype == CONSTRAINT_FOREIGN && con->confrelid != RelationGetRelid(rel)) { Relation frel; /* Must match lock taken by RemoveTriggerById: */ frel = table_open(con->confrelid, AccessExclusiveLock); CheckAlterTableIsSafe(frel); table_close(frel, NoLock); } /* * Perform the actual constraint deletion */ ObjectAddressSet(conobj, ConstraintRelationId, con->oid); performDeletion(&conobj, behavior, 0); /* * For partitioned tables, non-CHECK, non-NOT-NULL inherited constraints * are dropped via the dependency mechanism, so we're done here. */ if (con->contype != CONSTRAINT_CHECK && con->contype != CONSTRAINT_NOTNULL && rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) { table_close(conrel, RowExclusiveLock); return conobj; } /* * Propagate to children as appropriate. Unlike most other ALTER * routines, we have to do this one level of recursion at a time; we can't * use find_all_inheritors to do it in one pass. */ if (!is_no_inherit_constraint) children = find_inheritance_children(RelationGetRelid(rel), lockmode); else children = NIL; foreach_oid(childrelid, children) { Relation childrel; HeapTuple tuple; Form_pg_constraint childcon; /* find_inheritance_children already got lock */ childrel = table_open(childrelid, NoLock); CheckAlterTableIsSafe(childrel); /* * We search for not-null constraints by column name, and others by * constraint name. */ if (con->contype == CONSTRAINT_NOTNULL) { tuple = findNotNullConstraint(childrelid, colname); if (!HeapTupleIsValid(tuple)) elog(ERROR, "cache lookup failed for not-null constraint on column \"%s\" of relation %u", colname, RelationGetRelid(childrel)); } else { SysScanDesc scan; ScanKeyData skey[3]; ScanKeyInit(&skey[0], Anum_pg_constraint_conrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(childrelid)); ScanKeyInit(&skey[1], Anum_pg_constraint_contypid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(InvalidOid)); ScanKeyInit(&skey[2], Anum_pg_constraint_conname, BTEqualStrategyNumber, F_NAMEEQ, CStringGetDatum(constrName)); scan = systable_beginscan(conrel, ConstraintRelidTypidNameIndexId, true, NULL, 3, skey); /* There can only be one, so no need to loop */ tuple = systable_getnext(scan); if (!HeapTupleIsValid(tuple)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_OBJECT), errmsg("constraint \"%s\" of relation \"%s\" does not exist", constrName, RelationGetRelationName(childrel)))); tuple = heap_copytuple(tuple); systable_endscan(scan); } childcon = (Form_pg_constraint) GETSTRUCT(tuple); /* Right now only CHECK and not-null constraints can be inherited */ if (childcon->contype != CONSTRAINT_CHECK && childcon->contype != CONSTRAINT_NOTNULL) elog(ERROR, "inherited constraint is not a CHECK or not-null constraint"); if (childcon->coninhcount <= 0) /* shouldn't happen */ elog(ERROR, "relation %u has non-inherited constraint \"%s\"", childrelid, NameStr(childcon->conname)); if (recurse) { /* * If the child constraint has other definition sources, just * decrement its inheritance count; if not, recurse to delete it. */ if (childcon->coninhcount == 1 && !childcon->conislocal) { /* Time to delete this child constraint, too */ dropconstraint_internal(childrel, tuple, behavior, recurse, true, missing_ok, lockmode); } else { /* Child constraint must survive my deletion */ childcon->coninhcount--; CatalogTupleUpdate(conrel, &tuple->t_self, tuple); /* Make update visible */ CommandCounterIncrement(); } } else { /* * If we were told to drop ONLY in this table (no recursion) and * there are no further parents for this constraint, we need to * mark the inheritors' constraints as locally defined rather than * inherited. */ childcon->coninhcount--; if (childcon->coninhcount == 0) childcon->conislocal = true; CatalogTupleUpdate(conrel, &tuple->t_self, tuple); /* Make update visible */ CommandCounterIncrement(); } heap_freetuple(tuple); table_close(childrel, NoLock); } table_close(conrel, RowExclusiveLock); return conobj; } /* * ALTER COLUMN TYPE * * Unlike other subcommand types, we do parse transformation for ALTER COLUMN * TYPE during phase 1 --- the AlterTableCmd passed in here is already * transformed (and must be, because we rely on some transformed fields). * * The point of this is that the execution of all ALTER COLUMN TYPEs for a * table will be done "in parallel" during phase 3, so all the USING * expressions should be parsed assuming the original column types. Also, * this allows a USING expression to refer to a field that will be dropped. * * To make this work safely, AT_PASS_DROP then AT_PASS_ALTER_TYPE must be * the first two execution steps in phase 2; they must not see the effects * of any other subcommand types, since the USING expressions are parsed * against the unmodified table's state. */ static void ATPrepAlterColumnType(List **wqueue, AlteredTableInfo *tab, Relation rel, bool recurse, bool recursing, AlterTableCmd *cmd, LOCKMODE lockmode, AlterTableUtilityContext *context) { char *colName = cmd->name; ColumnDef *def = (ColumnDef *) cmd->def; TypeName *typeName = def->typeName; Node *transform = def->cooked_default; HeapTuple tuple; Form_pg_attribute attTup; AttrNumber attnum; Oid targettype; int32 targettypmod; Oid targetcollid; NewColumnValue *newval; ParseState *pstate = make_parsestate(NULL); AclResult aclresult; bool is_expr; pstate->p_sourcetext = context->queryString; if (rel->rd_rel->reloftype && !recursing) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot alter column type of typed table"), parser_errposition(pstate, def->location))); /* lookup the attribute so we can check inheritance status */ tuple = SearchSysCacheAttName(RelationGetRelid(rel), colName); if (!HeapTupleIsValid(tuple)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" of relation \"%s\" does not exist", colName, RelationGetRelationName(rel)), parser_errposition(pstate, def->location))); attTup = (Form_pg_attribute) GETSTRUCT(tuple); attnum = attTup->attnum; /* Can't alter a system attribute */ if (attnum <= 0) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter system column \"%s\"", colName), parser_errposition(pstate, def->location))); /* * Cannot specify USING when altering type of a generated column, because * that would violate the generation expression. */ if (attTup->attgenerated && def->cooked_default) ereport(ERROR, (errcode(ERRCODE_INVALID_COLUMN_DEFINITION), errmsg("cannot specify USING when altering type of generated column"), errdetail("Column \"%s\" is a generated column.", colName), parser_errposition(pstate, def->location))); /* * Don't alter inherited columns. At outer level, there had better not be * any inherited definition; when recursing, we assume this was checked at * the parent level (see below). */ if (attTup->attinhcount > 0 && !recursing) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("cannot alter inherited column \"%s\"", colName), parser_errposition(pstate, def->location))); /* Don't alter columns used in the partition key */ if (has_partition_attrs(rel, bms_make_singleton(attnum - FirstLowInvalidHeapAttributeNumber), &is_expr)) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("cannot alter column \"%s\" because it is part of the partition key of relation \"%s\"", colName, RelationGetRelationName(rel)), parser_errposition(pstate, def->location))); /* Look up the target type */ typenameTypeIdAndMod(pstate, typeName, &targettype, &targettypmod); aclresult = object_aclcheck(TypeRelationId, targettype, GetUserId(), ACL_USAGE); if (aclresult != ACLCHECK_OK) aclcheck_error_type(aclresult, targettype); /* And the collation */ targetcollid = GetColumnDefCollation(pstate, def, targettype); /* make sure datatype is legal for a column */ CheckAttributeType(colName, targettype, targetcollid, list_make1_oid(rel->rd_rel->reltype), (attTup->attgenerated == ATTRIBUTE_GENERATED_VIRTUAL ? CHKATYPE_IS_VIRTUAL : 0)); if (attTup->attgenerated == ATTRIBUTE_GENERATED_VIRTUAL) { /* do nothing */ } else if (tab->relkind == RELKIND_RELATION || tab->relkind == RELKIND_PARTITIONED_TABLE) { /* * Set up an expression to transform the old data value to the new * type. If a USING option was given, use the expression as * transformed by transformAlterTableStmt, else just take the old * value and try to coerce it. We do this first so that type * incompatibility can be detected before we waste effort, and because * we need the expression to be parsed against the original table row * type. */ if (!transform) { transform = (Node *) makeVar(1, attnum, attTup->atttypid, attTup->atttypmod, attTup->attcollation, 0); } transform = coerce_to_target_type(pstate, transform, exprType(transform), targettype, targettypmod, COERCION_ASSIGNMENT, COERCE_IMPLICIT_CAST, -1); if (transform == NULL) { /* error text depends on whether USING was specified or not */ if (def->cooked_default != NULL) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("result of USING clause for column \"%s\"" " cannot be cast automatically to type %s", colName, format_type_be(targettype)), errhint("You might need to add an explicit cast."))); else ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("column \"%s\" cannot be cast automatically to type %s", colName, format_type_be(targettype)), !attTup->attgenerated ? /* translator: USING is SQL, don't translate it */ errhint("You might need to specify \"USING %s::%s\".", quote_identifier(colName), format_type_with_typemod(targettype, targettypmod)) : 0)); } /* Fix collations after all else */ assign_expr_collations(pstate, transform); /* Expand virtual generated columns in the expr. */ transform = expand_generated_columns_in_expr(transform, rel, 1); /* Plan the expr now so we can accurately assess the need to rewrite. */ transform = (Node *) expression_planner((Expr *) transform); /* * Add a work queue item to make ATRewriteTable update the column * contents. */ newval = palloc0_object(NewColumnValue); newval->attnum = attnum; newval->expr = (Expr *) transform; newval->is_generated = false; tab->newvals = lappend(tab->newvals, newval); if (ATColumnChangeRequiresRewrite(transform, attnum)) tab->rewrite |= AT_REWRITE_COLUMN_REWRITE; } else if (transform) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is not a table", RelationGetRelationName(rel)))); if (!RELKIND_HAS_STORAGE(tab->relkind) || attTup->attgenerated == ATTRIBUTE_GENERATED_VIRTUAL) { /* * For relations or columns without storage, do this check now. * Regular tables will check it later when the table is being * rewritten. */ find_composite_type_dependencies(rel->rd_rel->reltype, rel, NULL); } ReleaseSysCache(tuple); /* * Recurse manually by queueing a new command for each child, if * necessary. We cannot apply ATSimpleRecursion here because we need to * remap attribute numbers in the USING expression, if any. * * If we are told not to recurse, there had better not be any child * tables; else the alter would put them out of step. */ if (recurse) { Oid relid = RelationGetRelid(rel); List *child_oids, *child_numparents; ListCell *lo, *li; child_oids = find_all_inheritors(relid, lockmode, &child_numparents); /* * find_all_inheritors does the recursive search of the inheritance * hierarchy, so all we have to do is process all of the relids in the * list that it returns. */ forboth(lo, child_oids, li, child_numparents) { Oid childrelid = lfirst_oid(lo); int numparents = lfirst_int(li); Relation childrel; HeapTuple childtuple; Form_pg_attribute childattTup; if (childrelid == relid) continue; /* find_all_inheritors already got lock */ childrel = relation_open(childrelid, NoLock); CheckAlterTableIsSafe(childrel); /* * Verify that the child doesn't have any inherited definitions of * this column that came from outside this inheritance hierarchy. * (renameatt makes a similar test, though in a different way * because of its different recursion mechanism.) */ childtuple = SearchSysCacheAttName(RelationGetRelid(childrel), colName); if (!HeapTupleIsValid(childtuple)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" of relation \"%s\" does not exist", colName, RelationGetRelationName(childrel)))); childattTup = (Form_pg_attribute) GETSTRUCT(childtuple); if (childattTup->attinhcount > numparents) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("cannot alter inherited column \"%s\" of relation \"%s\"", colName, RelationGetRelationName(childrel)))); ReleaseSysCache(childtuple); /* * Remap the attribute numbers. If no USING expression was * specified, there is no need for this step. */ if (def->cooked_default) { AttrMap *attmap; bool found_whole_row; /* create a copy to scribble on */ cmd = copyObject(cmd); attmap = build_attrmap_by_name(RelationGetDescr(childrel), RelationGetDescr(rel), false); ((ColumnDef *) cmd->def)->cooked_default = map_variable_attnos(def->cooked_default, 1, 0, attmap, InvalidOid, &found_whole_row); if (found_whole_row) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot convert whole-row table reference"), errdetail("USING expression contains a whole-row table reference."))); pfree(attmap); } ATPrepCmd(wqueue, childrel, cmd, false, true, lockmode, context); relation_close(childrel, NoLock); } } else if (!recursing && find_inheritance_children(RelationGetRelid(rel), NoLock) != NIL) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("type of inherited column \"%s\" must be changed in child tables too", colName))); if (tab->relkind == RELKIND_COMPOSITE_TYPE) ATTypedTableRecursion(wqueue, rel, cmd, lockmode, context); } /* * When the data type of a column is changed, a rewrite might not be required * if the new type is sufficiently identical to the old one, and the USING * clause isn't trying to insert some other value. It's safe to skip the * rewrite in these cases: * * - the old type is binary coercible to the new type * - the new type is an unconstrained domain over the old type * - {NEW,OLD} or {OLD,NEW} is {timestamptz,timestamp} and the timezone is UTC * * In the case of a constrained domain, we could get by with scanning the * table and checking the constraint rather than actually rewriting it, but we * don't currently try to do that. */ static bool ATColumnChangeRequiresRewrite(Node *expr, AttrNumber varattno) { Assert(expr != NULL); for (;;) { /* only one varno, so no need to check that */ if (IsA(expr, Var) && ((Var *) expr)->varattno == varattno) return false; else if (IsA(expr, RelabelType)) expr = (Node *) ((RelabelType *) expr)->arg; else if (IsA(expr, CoerceToDomain)) { CoerceToDomain *d = (CoerceToDomain *) expr; if (DomainHasConstraints(d->resulttype, NULL)) return true; expr = (Node *) d->arg; } else if (IsA(expr, FuncExpr)) { FuncExpr *f = (FuncExpr *) expr; switch (f->funcid) { case F_TIMESTAMPTZ_TIMESTAMP: case F_TIMESTAMP_TIMESTAMPTZ: if (TimestampTimestampTzRequiresRewrite()) return true; else expr = linitial(f->args); break; default: return true; } } else return true; } } /* * ALTER COLUMN .. SET DATA TYPE * * Return the address of the modified column. */ static ObjectAddress ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel, AlterTableCmd *cmd, LOCKMODE lockmode) { char *colName = cmd->name; ColumnDef *def = (ColumnDef *) cmd->def; TypeName *typeName = def->typeName; HeapTuple heapTup; Form_pg_attribute attTup, attOldTup; AttrNumber attnum; HeapTuple typeTuple; Form_pg_type tform; Oid targettype; int32 targettypmod; Oid targetcollid; Node *defaultexpr; Relation attrelation; Relation depRel; ScanKeyData key[3]; SysScanDesc scan; HeapTuple depTup; ObjectAddress address; /* * Clear all the missing values if we're rewriting the table, since this * renders them pointless. */ if (tab->rewrite) { Relation newrel; newrel = table_open(RelationGetRelid(rel), NoLock); RelationClearMissing(newrel); relation_close(newrel, NoLock); /* make sure we don't conflict with later attribute modifications */ CommandCounterIncrement(); } attrelation = table_open(AttributeRelationId, RowExclusiveLock); /* Look up the target column */ heapTup = SearchSysCacheCopyAttName(RelationGetRelid(rel), colName); if (!HeapTupleIsValid(heapTup)) /* shouldn't happen */ ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" of relation \"%s\" does not exist", colName, RelationGetRelationName(rel)))); attTup = (Form_pg_attribute) GETSTRUCT(heapTup); attnum = attTup->attnum; attOldTup = TupleDescAttr(tab->oldDesc, attnum - 1); /* Check for multiple ALTER TYPE on same column --- can't cope */ if (attTup->atttypid != attOldTup->atttypid || attTup->atttypmod != attOldTup->atttypmod) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter type of column \"%s\" twice", colName))); /* Look up the target type (should not fail, since prep found it) */ typeTuple = typenameType(NULL, typeName, &targettypmod); tform = (Form_pg_type) GETSTRUCT(typeTuple); targettype = tform->oid; /* And the collation */ targetcollid = GetColumnDefCollation(NULL, def, targettype); /* * If there is a default expression for the column, get it and ensure we * can coerce it to the new datatype. (We must do this before changing * the column type, because build_column_default itself will try to * coerce, and will not issue the error message we want if it fails.) * * We remove any implicit coercion steps at the top level of the old * default expression; this has been agreed to satisfy the principle of * least surprise. (The conversion to the new column type should act like * it started from what the user sees as the stored expression, and the * implicit coercions aren't going to be shown.) */ if (attTup->atthasdef) { defaultexpr = build_column_default(rel, attnum); Assert(defaultexpr); defaultexpr = strip_implicit_coercions(defaultexpr); defaultexpr = coerce_to_target_type(NULL, /* no UNKNOWN params */ defaultexpr, exprType(defaultexpr), targettype, targettypmod, COERCION_ASSIGNMENT, COERCE_IMPLICIT_CAST, -1); if (defaultexpr == NULL) { if (attTup->attgenerated) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("generation expression for column \"%s\" cannot be cast automatically to type %s", colName, format_type_be(targettype)))); else ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("default for column \"%s\" cannot be cast automatically to type %s", colName, format_type_be(targettype)))); } } else defaultexpr = NULL; /* * Find everything that depends on the column (constraints, indexes, etc), * and record enough information to let us recreate the objects. * * The actual recreation does not happen here, but only after we have * performed all the individual ALTER TYPE operations. We have to save * the info before executing ALTER TYPE, though, else the deparser will * get confused. */ RememberAllDependentForRebuilding(tab, AT_AlterColumnType, rel, attnum, colName); /* * Now scan for dependencies of this column on other things. The only * things we should find are the dependency on the column datatype and * possibly a collation dependency. Those can be removed. */ depRel = table_open(DependRelationId, RowExclusiveLock); ScanKeyInit(&key[0], Anum_pg_depend_classid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationRelationId)); ScanKeyInit(&key[1], Anum_pg_depend_objid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(rel))); ScanKeyInit(&key[2], Anum_pg_depend_objsubid, BTEqualStrategyNumber, F_INT4EQ, Int32GetDatum((int32) attnum)); scan = systable_beginscan(depRel, DependDependerIndexId, true, NULL, 3, key); while (HeapTupleIsValid(depTup = systable_getnext(scan))) { Form_pg_depend foundDep = (Form_pg_depend) GETSTRUCT(depTup); ObjectAddress foundObject; foundObject.classId = foundDep->refclassid; foundObject.objectId = foundDep->refobjid; foundObject.objectSubId = foundDep->refobjsubid; if (foundDep->deptype != DEPENDENCY_NORMAL) elog(ERROR, "found unexpected dependency type '%c'", foundDep->deptype); if (!(foundDep->refclassid == TypeRelationId && foundDep->refobjid == attTup->atttypid) && !(foundDep->refclassid == CollationRelationId && foundDep->refobjid == attTup->attcollation)) elog(ERROR, "found unexpected dependency for column: %s", getObjectDescription(&foundObject, false)); CatalogTupleDelete(depRel, &depTup->t_self); } systable_endscan(scan); table_close(depRel, RowExclusiveLock); /* * Here we go --- change the recorded column type and collation. (Note * heapTup is a copy of the syscache entry, so okay to scribble on.) First * fix up the missing value if any. */ if (attTup->atthasmissing) { Datum missingval; bool missingNull; /* if rewrite is true the missing value should already be cleared */ Assert(tab->rewrite == 0); /* Get the missing value datum */ missingval = heap_getattr(heapTup, Anum_pg_attribute_attmissingval, attrelation->rd_att, &missingNull); /* if it's a null array there is nothing to do */ if (!missingNull) { /* * Get the datum out of the array and repack it in a new array * built with the new type data. We assume that since the table * doesn't need rewriting, the actual Datum doesn't need to be * changed, only the array metadata. */ int one = 1; bool isNull; Datum valuesAtt[Natts_pg_attribute] = {0}; bool nullsAtt[Natts_pg_attribute] = {0}; bool replacesAtt[Natts_pg_attribute] = {0}; HeapTuple newTup; missingval = array_get_element(missingval, 1, &one, 0, attTup->attlen, attTup->attbyval, attTup->attalign, &isNull); missingval = PointerGetDatum(construct_array(&missingval, 1, targettype, tform->typlen, tform->typbyval, tform->typalign)); valuesAtt[Anum_pg_attribute_attmissingval - 1] = missingval; replacesAtt[Anum_pg_attribute_attmissingval - 1] = true; nullsAtt[Anum_pg_attribute_attmissingval - 1] = false; newTup = heap_modify_tuple(heapTup, RelationGetDescr(attrelation), valuesAtt, nullsAtt, replacesAtt); heap_freetuple(heapTup); heapTup = newTup; attTup = (Form_pg_attribute) GETSTRUCT(heapTup); } } attTup->atttypid = targettype; attTup->atttypmod = targettypmod; attTup->attcollation = targetcollid; if (list_length(typeName->arrayBounds) > PG_INT16_MAX) ereport(ERROR, errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED), errmsg("too many array dimensions")); attTup->attndims = list_length(typeName->arrayBounds); attTup->attlen = tform->typlen; attTup->attbyval = tform->typbyval; attTup->attalign = tform->typalign; attTup->attstorage = tform->typstorage; attTup->attcompression = InvalidCompressionMethod; ReleaseSysCache(typeTuple); CatalogTupleUpdate(attrelation, &heapTup->t_self, heapTup); table_close(attrelation, RowExclusiveLock); /* Install dependencies on new datatype and collation */ add_column_datatype_dependency(RelationGetRelid(rel), attnum, targettype); add_column_collation_dependency(RelationGetRelid(rel), attnum, targetcollid); /* * Drop any pg_statistic entry for the column, since it's now wrong type */ RemoveStatistics(RelationGetRelid(rel), attnum); InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), attnum); /* * Update the default, if present, by brute force --- remove and re-add * the default. Probably unsafe to take shortcuts, since the new version * may well have additional dependencies. (It's okay to do this now, * rather than after other ALTER TYPE commands, since the default won't * depend on other column types.) */ if (defaultexpr) { /* * If it's a GENERATED default, drop its dependency records, in * particular its INTERNAL dependency on the column, which would * otherwise cause dependency.c to refuse to perform the deletion. */ if (attTup->attgenerated) { Oid attrdefoid = GetAttrDefaultOid(RelationGetRelid(rel), attnum); if (!OidIsValid(attrdefoid)) elog(ERROR, "could not find attrdef tuple for relation %u attnum %d", RelationGetRelid(rel), attnum); (void) deleteDependencyRecordsFor(AttrDefaultRelationId, attrdefoid, false); } /* * Make updates-so-far visible, particularly the new pg_attribute row * which will be updated again. */ CommandCounterIncrement(); /* * We use RESTRICT here for safety, but at present we do not expect * anything to depend on the default. */ RemoveAttrDefault(RelationGetRelid(rel), attnum, DROP_RESTRICT, true, true); (void) StoreAttrDefault(rel, attnum, defaultexpr, true); } ObjectAddressSubSet(address, RelationRelationId, RelationGetRelid(rel), attnum); /* Cleanup */ heap_freetuple(heapTup); return address; } /* * Subroutine for ATExecAlterColumnType and ATExecSetExpression: Find everything * that depends on the column (constraints, indexes, etc), and record enough * information to let us recreate the objects. */ static void RememberAllDependentForRebuilding(AlteredTableInfo *tab, AlterTableType subtype, Relation rel, AttrNumber attnum, const char *colName) { Relation depRel; ScanKeyData key[3]; SysScanDesc scan; HeapTuple depTup; Assert(subtype == AT_AlterColumnType || subtype == AT_SetExpression); depRel = table_open(DependRelationId, RowExclusiveLock); ScanKeyInit(&key[0], Anum_pg_depend_refclassid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationRelationId)); ScanKeyInit(&key[1], Anum_pg_depend_refobjid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(rel))); ScanKeyInit(&key[2], Anum_pg_depend_refobjsubid, BTEqualStrategyNumber, F_INT4EQ, Int32GetDatum((int32) attnum)); scan = systable_beginscan(depRel, DependReferenceIndexId, true, NULL, 3, key); while (HeapTupleIsValid(depTup = systable_getnext(scan))) { Form_pg_depend foundDep = (Form_pg_depend) GETSTRUCT(depTup); ObjectAddress foundObject; foundObject.classId = foundDep->classid; foundObject.objectId = foundDep->objid; foundObject.objectSubId = foundDep->objsubid; switch (foundObject.classId) { case RelationRelationId: { char relKind = get_rel_relkind(foundObject.objectId); if (relKind == RELKIND_INDEX || relKind == RELKIND_PARTITIONED_INDEX) { Assert(foundObject.objectSubId == 0); RememberIndexForRebuilding(foundObject.objectId, tab); } else if (relKind == RELKIND_SEQUENCE) { /* * This must be a SERIAL column's sequence. We need * not do anything to it. */ Assert(foundObject.objectSubId == 0); } else { /* Not expecting any other direct dependencies... */ elog(ERROR, "unexpected object depending on column: %s", getObjectDescription(&foundObject, false)); } break; } case ConstraintRelationId: Assert(foundObject.objectSubId == 0); RememberConstraintForRebuilding(foundObject.objectId, tab); break; case ProcedureRelationId: /* * A new-style SQL function can depend on a column, if that * column is referenced in the parsed function body. Ideally * we'd automatically update the function by deparsing and * reparsing it, but that's risky and might well fail anyhow. * FIXME someday. * * This is only a problem for AT_AlterColumnType, not * AT_SetExpression. */ if (subtype == AT_AlterColumnType) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter type of a column used by a function or procedure"), errdetail("%s depends on column \"%s\".", getObjectDescription(&foundObject, false), colName))); break; case RewriteRelationId: /* * View/rule bodies have pretty much the same issues as * function bodies. FIXME someday. */ if (subtype == AT_AlterColumnType) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter type of a column used by a view or rule"), errdetail("%s depends on column \"%s\".", getObjectDescription(&foundObject, false), colName))); break; case TriggerRelationId: /* * A trigger can depend on a column because the column is * specified as an update target, or because the column is * used in the trigger's WHEN condition. The first case would * not require any extra work, but the second case would * require updating the WHEN expression, which has the same * issues as above. Since we can't easily tell which case * applies, we punt for both. FIXME someday. */ if (subtype == AT_AlterColumnType) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter type of a column used in a trigger definition"), errdetail("%s depends on column \"%s\".", getObjectDescription(&foundObject, false), colName))); break; case PolicyRelationId: /* * A policy can depend on a column because the column is * specified in the policy's USING or WITH CHECK qual * expressions. It might be possible to rewrite and recheck * the policy expression, but punt for now. It's certainly * easy enough to remove and recreate the policy; still, FIXME * someday. */ if (subtype == AT_AlterColumnType) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter type of a column used in a policy definition"), errdetail("%s depends on column \"%s\".", getObjectDescription(&foundObject, false), colName))); break; case AttrDefaultRelationId: { ObjectAddress col = GetAttrDefaultColumnAddress(foundObject.objectId); if (col.objectId == RelationGetRelid(rel) && col.objectSubId == attnum) { /* * Ignore the column's own default expression. The * caller deals with it. */ } else { /* * This must be a reference from the expression of a * generated column elsewhere in the same table. * Changing the type/generated expression of a column * that is used by a generated column is not allowed * by SQL standard, so just punt for now. It might be * doable with some thinking and effort. */ if (subtype == AT_AlterColumnType) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter type of a column used by a generated column"), errdetail("Column \"%s\" is used by generated column \"%s\".", colName, get_attname(col.objectId, col.objectSubId, false)))); } break; } case StatisticExtRelationId: /* * Give the extended-stats machinery a chance to fix anything * that this column type change would break. */ RememberStatisticsForRebuilding(foundObject.objectId, tab); break; case PublicationRelRelationId: /* * Column reference in a PUBLICATION ... FOR TABLE ... WHERE * clause. Same issues as above. FIXME someday. */ if (subtype == AT_AlterColumnType) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter type of a column used by a publication WHERE clause"), errdetail("%s depends on column \"%s\".", getObjectDescription(&foundObject, false), colName))); break; default: /* * We don't expect any other sorts of objects to depend on a * column. */ elog(ERROR, "unexpected object depending on column: %s", getObjectDescription(&foundObject, false)); break; } } systable_endscan(scan); table_close(depRel, NoLock); } /* * Record information about dependencies between objects with whole-row Var * references (indexes, check constraints, etc.) and the relation. * * See also RememberAllDependentForRebuilding, which handles non-whole-row Var * references. * * This function currently applies only to ALTER COLUMN SET EXPRESSION. */ static void RememberWholeRowDependentForRebuilding(AlteredTableInfo *tab, AlterTableType subtype, Relation rel) { ScanKeyData skey; Relation pg_constraint; Relation pg_index; SysScanDesc conscan; SysScanDesc indscan; HeapTuple constrTuple; HeapTuple indexTuple; bool isnull; Assert(subtype == AT_SetExpression); /* * Check CHECK constraints with whole-row references first. */ if (RelationGetDescr(rel)->constr && RelationGetDescr(rel)->constr->num_check > 0) { pg_constraint = table_open(ConstraintRelationId, AccessShareLock); ScanKeyInit(&skey, Anum_pg_constraint_conrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(rel))); conscan = systable_beginscan(pg_constraint, ConstraintRelidTypidNameIndexId, true, NULL, 1, &skey); while (HeapTupleIsValid(constrTuple = systable_getnext(conscan))) { Form_pg_constraint conform = (Form_pg_constraint) GETSTRUCT(constrTuple); Datum exprDatum; if (conform->contype != CONSTRAINT_CHECK) continue; exprDatum = heap_getattr(constrTuple, Anum_pg_constraint_conbin, RelationGetDescr(pg_constraint), &isnull); if (isnull) elog(ERROR, "null conbin for relation \"%s\"", RelationGetRelationName(rel)); else { char *exprString; Node *expr; Bitmapset *expr_attrs = NULL; exprString = TextDatumGetCString(exprDatum); expr = stringToNode(exprString); pfree(exprString); /* Find all attributes referenced */ pull_varattnos(expr, 1, &expr_attrs); /* * If the CHECK constraint contains whole-row reference then * remember it. */ if (bms_is_member(InvalidAttrNumber - FirstLowInvalidHeapAttributeNumber, expr_attrs)) { RememberConstraintForRebuilding(conform->oid, tab); } } } systable_endscan(conscan); table_close(pg_constraint, AccessShareLock); } /* * Now check indexes with whole-row references. Prepare to scan pg_index * for entries having indrelid matching this relation. */ ScanKeyInit(&skey, Anum_pg_index_indrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(rel))); pg_index = table_open(IndexRelationId, AccessShareLock); indscan = systable_beginscan(pg_index, IndexIndrelidIndexId, true, NULL, 1, &skey); while (HeapTupleIsValid(indexTuple = systable_getnext(indscan))) { Form_pg_index index = (Form_pg_index) GETSTRUCT(indexTuple); Datum exprDatum; exprDatum = heap_getattr(indexTuple, Anum_pg_index_indexprs, RelationGetDescr(pg_index), &isnull); if (!isnull) { char *exprString; Node *expr; Bitmapset *expr_attrs = NULL; exprString = TextDatumGetCString(exprDatum); expr = stringToNode(exprString); pfree(exprString); /* Find all attributes referenced */ pull_varattnos(expr, 1, &expr_attrs); /* * If the index expression contains a whole-row reference then * remember it. */ if (bms_is_member(InvalidAttrNumber - FirstLowInvalidHeapAttributeNumber, expr_attrs)) { RememberIndexForRebuilding(index->indexrelid, tab); continue; } } exprDatum = heap_getattr(indexTuple, Anum_pg_index_indpred, RelationGetDescr(pg_index), &isnull); if (!isnull) { char *exprString; Node *expr; Bitmapset *expr_attrs = NULL; exprString = TextDatumGetCString(exprDatum); expr = stringToNode(exprString); pfree(exprString); /* Find all attributes referenced */ pull_varattnos(expr, 1, &expr_attrs); /* * If the index predicate expression contains a whole-row * reference then remember it. */ if (bms_is_member(InvalidAttrNumber - FirstLowInvalidHeapAttributeNumber, expr_attrs)) { RememberIndexForRebuilding(index->indexrelid, tab); } } } systable_endscan(indscan); table_close(pg_index, AccessShareLock); } /* * Subroutine for ATExecAlterColumnType: remember that a replica identity * needs to be reset. */ static void RememberReplicaIdentityForRebuilding(Oid indoid, AlteredTableInfo *tab) { if (!get_index_isreplident(indoid)) return; if (tab->replicaIdentityIndex) elog(ERROR, "relation %u has multiple indexes marked as replica identity", tab->relid); tab->replicaIdentityIndex = get_rel_name(indoid); } /* * Subroutine for ATExecAlterColumnType: remember any clustered index. */ static void RememberClusterOnForRebuilding(Oid indoid, AlteredTableInfo *tab) { if (!get_index_isclustered(indoid)) return; if (tab->clusterOnIndex) elog(ERROR, "relation %u has multiple clustered indexes", tab->relid); tab->clusterOnIndex = get_rel_name(indoid); } /* * Subroutine for ATExecAlterColumnType: remember that a constraint needs * to be rebuilt (which we might already know). */ static void RememberConstraintForRebuilding(Oid conoid, AlteredTableInfo *tab) { /* * This de-duplication check is critical for two independent reasons: we * mustn't try to recreate the same constraint twice, and if a constraint * depends on more than one column whose type is to be altered, we must * capture its definition string before applying any of the column type * changes. ruleutils.c will get confused if we ask again later. */ if (!list_member_oid(tab->changedConstraintOids, conoid)) { /* OK, capture the constraint's existing definition string */ char *defstring = pg_get_constraintdef_command(conoid); Oid indoid; /* * It is critical to create not-null constraints ahead of primary key * indexes; otherwise, the not-null constraint would be created by the * primary key, and the constraint name would be wrong. */ if (get_constraint_type(conoid) == CONSTRAINT_NOTNULL) { tab->changedConstraintOids = lcons_oid(conoid, tab->changedConstraintOids); tab->changedConstraintDefs = lcons(defstring, tab->changedConstraintDefs); } else { tab->changedConstraintOids = lappend_oid(tab->changedConstraintOids, conoid); tab->changedConstraintDefs = lappend(tab->changedConstraintDefs, defstring); } /* * For the index of a constraint, if any, remember if it is used for * the table's replica identity or if it is a clustered index, so that * ATPostAlterTypeCleanup() can queue up commands necessary to restore * those properties. */ indoid = get_constraint_index(conoid); if (OidIsValid(indoid)) { RememberReplicaIdentityForRebuilding(indoid, tab); RememberClusterOnForRebuilding(indoid, tab); } } } /* * Subroutine for ATExecAlterColumnType: remember that an index needs * to be rebuilt (which we might already know). */ static void RememberIndexForRebuilding(Oid indoid, AlteredTableInfo *tab) { /* * This de-duplication check is critical for two independent reasons: we * mustn't try to recreate the same index twice, and if an index depends * on more than one column whose type is to be altered, we must capture * its definition string before applying any of the column type changes. * ruleutils.c will get confused if we ask again later. */ if (!list_member_oid(tab->changedIndexOids, indoid)) { /* * Before adding it as an index-to-rebuild, we'd better see if it * belongs to a constraint, and if so rebuild the constraint instead. * Typically this check fails, because constraint indexes normally * have only dependencies on their constraint. But it's possible for * such an index to also have direct dependencies on table columns, * for example with a partial exclusion constraint. */ Oid conoid = get_index_constraint(indoid); if (OidIsValid(conoid)) { RememberConstraintForRebuilding(conoid, tab); } else { /* OK, capture the index's existing definition string */ char *defstring = pg_get_indexdef_string(indoid); tab->changedIndexOids = lappend_oid(tab->changedIndexOids, indoid); tab->changedIndexDefs = lappend(tab->changedIndexDefs, defstring); /* * Remember if this index is used for the table's replica identity * or if it is a clustered index, so that ATPostAlterTypeCleanup() * can queue up commands necessary to restore those properties. */ RememberReplicaIdentityForRebuilding(indoid, tab); RememberClusterOnForRebuilding(indoid, tab); } } } /* * Subroutine for ATExecAlterColumnType: remember that a statistics object * needs to be rebuilt (which we might already know). */ static void RememberStatisticsForRebuilding(Oid stxoid, AlteredTableInfo *tab) { /* * This de-duplication check is critical for two independent reasons: we * mustn't try to recreate the same statistics object twice, and if the * statistics object depends on more than one column whose type is to be * altered, we must capture its definition string before applying any of * the type changes. ruleutils.c will get confused if we ask again later. */ if (!list_member_oid(tab->changedStatisticsOids, stxoid)) { /* OK, capture the statistics object's existing definition string */ char *defstring = pg_get_statisticsobjdef_string(stxoid); HeapTuple tup; Form_pg_statistic_ext statext; tup = SearchSysCache1(STATEXTOID, ObjectIdGetDatum(stxoid)); if (!HeapTupleIsValid(tup)) /* should not happen */ elog(ERROR, "cache lookup failed for statistics object %u", stxoid); statext = (Form_pg_statistic_ext) GETSTRUCT(tup); tab->changedStatisticsOids = lappend_oid(tab->changedStatisticsOids, stxoid); tab->changedStatisticsDefs = lappend(tab->changedStatisticsDefs, defstring); tab->changedStatisticsOwners = lappend_oid(tab->changedStatisticsOwners, statext->stxowner); ReleaseSysCache(tup); } } /* * Cleanup after we've finished all the ALTER TYPE or SET EXPRESSION * operations for a particular relation. We have to drop and recreate all the * indexes and constraints that depend on the altered columns. We do the * actual dropping here, but re-creation is managed by adding work queue * entries to do those steps later. */ static void ATPostAlterTypeCleanup(List **wqueue, AlteredTableInfo *tab, LOCKMODE lockmode) { ObjectAddress obj; ObjectAddresses *objects; ListCell *def_item; ListCell *oid_item; ListCell *owner_item; /* * Collect all the constraints and indexes to drop so we can process them * in a single call. That way we don't have to worry about dependencies * among them. */ objects = new_object_addresses(); /* * Re-parse the index and constraint definitions, and attach them to the * appropriate work queue entries. We do this before dropping because in * the case of a constraint on another table, we might not yet have * exclusive lock on the table the constraint is attached to, and we need * to get that before reparsing/dropping. (That's possible at least for * FOREIGN KEY, CHECK, and EXCLUSION constraints; in non-FK cases it * requires a dependency on the target table's composite type in the other * table's constraint expressions.) * * We can't rely on the output of deparsing to tell us which relation to * operate on, because concurrent activity might have made the name * resolve differently. Instead, we've got to use the OID of the * constraint or index we're processing to figure out which relation to * operate on. */ forboth(oid_item, tab->changedConstraintOids, def_item, tab->changedConstraintDefs) { Oid oldId = lfirst_oid(oid_item); HeapTuple tup; Form_pg_constraint con; Oid relid; Oid confrelid; bool conislocal; tup = SearchSysCache1(CONSTROID, ObjectIdGetDatum(oldId)); if (!HeapTupleIsValid(tup)) /* should not happen */ elog(ERROR, "cache lookup failed for constraint %u", oldId); con = (Form_pg_constraint) GETSTRUCT(tup); if (OidIsValid(con->conrelid)) relid = con->conrelid; else { /* must be a domain constraint */ relid = get_typ_typrelid(getBaseType(con->contypid)); if (!OidIsValid(relid)) elog(ERROR, "could not identify relation associated with constraint %u", oldId); } confrelid = con->confrelid; conislocal = con->conislocal; ReleaseSysCache(tup); ObjectAddressSet(obj, ConstraintRelationId, oldId); add_exact_object_address(&obj, objects); /* * If the constraint is inherited (only), we don't want to inject a * new definition here; it'll get recreated when * ATAddCheckNNConstraint recurses from adding the parent table's * constraint. But we had to carry the info this far so that we can * drop the constraint below. */ if (!conislocal) continue; /* * When rebuilding another table's constraint that references the * table we're modifying, we might not yet have any lock on the other * table, so get one now. We'll need AccessExclusiveLock for the DROP * CONSTRAINT step, so there's no value in asking for anything weaker. */ if (relid != tab->relid) LockRelationOid(relid, AccessExclusiveLock); ATPostAlterTypeParse(oldId, relid, confrelid, InvalidOid, (char *) lfirst(def_item), wqueue, lockmode, tab->rewrite); } forboth(oid_item, tab->changedIndexOids, def_item, tab->changedIndexDefs) { Oid oldId = lfirst_oid(oid_item); Oid relid; relid = IndexGetRelation(oldId, false); /* * As above, make sure we have lock on the index's table if it's not * the same table. */ if (relid != tab->relid) LockRelationOid(relid, AccessExclusiveLock); ATPostAlterTypeParse(oldId, relid, InvalidOid, InvalidOid, (char *) lfirst(def_item), wqueue, lockmode, tab->rewrite); ObjectAddressSet(obj, RelationRelationId, oldId); add_exact_object_address(&obj, objects); } /* add dependencies for new statistics */ forthree(oid_item, tab->changedStatisticsOids, def_item, tab->changedStatisticsDefs, owner_item, tab->changedStatisticsOwners) { Oid oldId = lfirst_oid(oid_item); Oid relid; relid = StatisticsGetRelation(oldId, false); /* * As above, make sure we have lock on the statistics object's table * if it's not the same table. However, we take * ShareUpdateExclusiveLock here, aligning with the lock level used in * CreateStatistics and RemoveStatisticsById. * * CAUTION: this should be done after all cases that grab * AccessExclusiveLock, else we risk causing deadlock due to needing * to promote our table lock. */ if (relid != tab->relid) LockRelationOid(relid, ShareUpdateExclusiveLock); ATPostAlterTypeParse(oldId, relid, InvalidOid, lfirst_oid(owner_item), (char *) lfirst(def_item), wqueue, lockmode, tab->rewrite); ObjectAddressSet(obj, StatisticExtRelationId, oldId); add_exact_object_address(&obj, objects); } /* * Queue up command to restore replica identity index marking */ if (tab->replicaIdentityIndex) { AlterTableCmd *cmd = makeNode(AlterTableCmd); ReplicaIdentityStmt *subcmd = makeNode(ReplicaIdentityStmt); subcmd->identity_type = REPLICA_IDENTITY_INDEX; subcmd->name = tab->replicaIdentityIndex; cmd->subtype = AT_ReplicaIdentity; cmd->def = (Node *) subcmd; /* do it after indexes and constraints */ tab->subcmds[AT_PASS_OLD_CONSTR] = lappend(tab->subcmds[AT_PASS_OLD_CONSTR], cmd); } /* * Queue up command to restore marking of index used for cluster. */ if (tab->clusterOnIndex) { AlterTableCmd *cmd = makeNode(AlterTableCmd); cmd->subtype = AT_ClusterOn; cmd->name = tab->clusterOnIndex; /* do it after indexes and constraints */ tab->subcmds[AT_PASS_OLD_CONSTR] = lappend(tab->subcmds[AT_PASS_OLD_CONSTR], cmd); } /* * It should be okay to use DROP_RESTRICT here, since nothing else should * be depending on these objects. */ performMultipleDeletions(objects, DROP_RESTRICT, PERFORM_DELETION_INTERNAL); free_object_addresses(objects); /* * The objects will get recreated during subsequent passes over the work * queue. */ } /* * Parse the previously-saved definition string for a constraint, index or * statistics object against the newly-established column data type(s), and * queue up the resulting command parsetrees for execution. * * This might fail if, for example, you have a WHERE clause that uses an * operator that's not available for the new column type. */ static void ATPostAlterTypeParse(Oid oldId, Oid oldRelId, Oid refRelId, Oid ownerId, char *cmd, List **wqueue, LOCKMODE lockmode, bool rewrite) { List *raw_parsetree_list; List *querytree_list; ListCell *list_item; Relation rel; /* * We expect that we will get only ALTER TABLE and CREATE INDEX * statements. Hence, there is no need to pass them through * parse_analyze_*() or the rewriter, but instead we need to pass them * through parse_utilcmd.c to make them ready for execution. */ raw_parsetree_list = raw_parser(cmd, RAW_PARSE_DEFAULT); querytree_list = NIL; foreach(list_item, raw_parsetree_list) { RawStmt *rs = lfirst_node(RawStmt, list_item); Node *stmt = rs->stmt; if (IsA(stmt, IndexStmt)) querytree_list = lappend(querytree_list, transformIndexStmt(oldRelId, (IndexStmt *) stmt, cmd)); else if (IsA(stmt, AlterTableStmt)) { List *beforeStmts; List *afterStmts; stmt = (Node *) transformAlterTableStmt(oldRelId, (AlterTableStmt *) stmt, cmd, &beforeStmts, &afterStmts); querytree_list = list_concat(querytree_list, beforeStmts); querytree_list = lappend(querytree_list, stmt); querytree_list = list_concat(querytree_list, afterStmts); } else if (IsA(stmt, CreateStatsStmt)) { CreateStatsStmt *csstmt; csstmt = transformStatsStmt(oldRelId, (CreateStatsStmt *) stmt, cmd); csstmt->owner = ownerId; querytree_list = lappend(querytree_list, csstmt); } else querytree_list = lappend(querytree_list, stmt); } /* Caller should already have acquired whatever lock we need. */ rel = relation_open(oldRelId, NoLock); /* * Attach each generated command to the proper place in the work queue. * Note this could result in creation of entirely new work-queue entries. * * Also note that we have to tweak the command subtypes, because it turns * out that re-creation of indexes and constraints has to act a bit * differently from initial creation. */ foreach(list_item, querytree_list) { Node *stm = (Node *) lfirst(list_item); AlteredTableInfo *tab; tab = ATGetQueueEntry(wqueue, rel); if (IsA(stm, IndexStmt)) { IndexStmt *stmt = (IndexStmt *) stm; AlterTableCmd *newcmd; if (!rewrite) TryReuseIndex(oldId, stmt); stmt->reset_default_tblspc = true; /* keep the index's comment */ stmt->idxcomment = GetComment(oldId, RelationRelationId, 0); newcmd = makeNode(AlterTableCmd); newcmd->subtype = AT_ReAddIndex; newcmd->def = (Node *) stmt; tab->subcmds[AT_PASS_OLD_INDEX] = lappend(tab->subcmds[AT_PASS_OLD_INDEX], newcmd); } else if (IsA(stm, AlterTableStmt)) { AlterTableStmt *stmt = (AlterTableStmt *) stm; ListCell *lcmd; foreach(lcmd, stmt->cmds) { AlterTableCmd *cmd = lfirst_node(AlterTableCmd, lcmd); if (cmd->subtype == AT_AddIndex) { IndexStmt *indstmt; Oid indoid; indstmt = castNode(IndexStmt, cmd->def); indoid = get_constraint_index(oldId); if (!rewrite) TryReuseIndex(indoid, indstmt); /* keep any comment on the index */ indstmt->idxcomment = GetComment(indoid, RelationRelationId, 0); indstmt->reset_default_tblspc = true; cmd->subtype = AT_ReAddIndex; tab->subcmds[AT_PASS_OLD_INDEX] = lappend(tab->subcmds[AT_PASS_OLD_INDEX], cmd); /* recreate any comment on the constraint */ RebuildConstraintComment(tab, AT_PASS_OLD_INDEX, oldId, rel, NIL, indstmt->idxname); } else if (cmd->subtype == AT_AddConstraint) { Constraint *con = castNode(Constraint, cmd->def); con->old_pktable_oid = refRelId; /* rewriting neither side of a FK */ if (con->contype == CONSTR_FOREIGN && !rewrite && tab->rewrite == 0) TryReuseForeignKey(oldId, con); con->reset_default_tblspc = true; cmd->subtype = AT_ReAddConstraint; tab->subcmds[AT_PASS_OLD_CONSTR] = lappend(tab->subcmds[AT_PASS_OLD_CONSTR], cmd); /* * Recreate any comment on the constraint. If we have * recreated a primary key, then transformTableConstraint * has added an unnamed not-null constraint here; skip * this in that case. */ if (con->conname) RebuildConstraintComment(tab, AT_PASS_OLD_CONSTR, oldId, rel, NIL, con->conname); else Assert(con->contype == CONSTR_NOTNULL); } else elog(ERROR, "unexpected statement subtype: %d", (int) cmd->subtype); } } else if (IsA(stm, AlterDomainStmt)) { AlterDomainStmt *stmt = (AlterDomainStmt *) stm; if (stmt->subtype == AD_AddConstraint) { Constraint *con = castNode(Constraint, stmt->def); AlterTableCmd *cmd = makeNode(AlterTableCmd); cmd->subtype = AT_ReAddDomainConstraint; cmd->def = (Node *) stmt; tab->subcmds[AT_PASS_OLD_CONSTR] = lappend(tab->subcmds[AT_PASS_OLD_CONSTR], cmd); /* recreate any comment on the constraint */ RebuildConstraintComment(tab, AT_PASS_OLD_CONSTR, oldId, NULL, stmt->typeName, con->conname); } else elog(ERROR, "unexpected statement subtype: %d", (int) stmt->subtype); } else if (IsA(stm, CreateStatsStmt)) { CreateStatsStmt *stmt = (CreateStatsStmt *) stm; AlterTableCmd *newcmd; /* keep the statistics object's comment */ stmt->stxcomment = GetComment(oldId, StatisticExtRelationId, 0); newcmd = makeNode(AlterTableCmd); newcmd->subtype = AT_ReAddStatistics; newcmd->def = (Node *) stmt; tab->subcmds[AT_PASS_MISC] = lappend(tab->subcmds[AT_PASS_MISC], newcmd); } else elog(ERROR, "unexpected statement type: %d", (int) nodeTag(stm)); } relation_close(rel, NoLock); } /* * Subroutine for ATPostAlterTypeParse() to recreate any existing comment * for a table or domain constraint that is being rebuilt. * * objid is the OID of the constraint. * Pass "rel" for a table constraint, or "domname" (domain's qualified name * as a string list) for a domain constraint. * (We could dig that info, as well as the conname, out of the pg_constraint * entry; but callers already have them so might as well pass them.) */ static void RebuildConstraintComment(AlteredTableInfo *tab, AlterTablePass pass, Oid objid, Relation rel, List *domname, const char *conname) { CommentStmt *cmd; char *comment_str; AlterTableCmd *newcmd; /* Look for comment for object wanted, and leave if none */ comment_str = GetComment(objid, ConstraintRelationId, 0); if (comment_str == NULL) return; /* Build CommentStmt node, copying all input data for safety */ cmd = makeNode(CommentStmt); if (rel) { cmd->objtype = OBJECT_TABCONSTRAINT; cmd->object = (Node *) list_make3(makeString(get_namespace_name(RelationGetNamespace(rel))), makeString(pstrdup(RelationGetRelationName(rel))), makeString(pstrdup(conname))); } else { cmd->objtype = OBJECT_DOMCONSTRAINT; cmd->object = (Node *) list_make2(makeTypeNameFromNameList(copyObject(domname)), makeString(pstrdup(conname))); } cmd->comment = comment_str; /* Append it to list of commands */ newcmd = makeNode(AlterTableCmd); newcmd->subtype = AT_ReAddComment; newcmd->def = (Node *) cmd; tab->subcmds[pass] = lappend(tab->subcmds[pass], newcmd); } /* * Subroutine for ATPostAlterTypeParse(). Calls out to CheckIndexCompatible() * for the real analysis, then mutates the IndexStmt based on that verdict. */ static void TryReuseIndex(Oid oldId, IndexStmt *stmt) { if (CheckIndexCompatible(oldId, stmt->accessMethod, stmt->indexParams, stmt->excludeOpNames, stmt->iswithoutoverlaps)) { Relation irel = index_open(oldId, NoLock); /* If it's a partitioned index, there is no storage to share. */ if (irel->rd_rel->relkind != RELKIND_PARTITIONED_INDEX) { stmt->oldNumber = irel->rd_locator.relNumber; stmt->oldCreateSubid = irel->rd_createSubid; stmt->oldFirstRelfilelocatorSubid = irel->rd_firstRelfilelocatorSubid; } index_close(irel, NoLock); } } /* * Subroutine for ATPostAlterTypeParse(). * * Stash the old P-F equality operator into the Constraint node, for possible * use by ATAddForeignKeyConstraint() in determining whether revalidation of * this constraint can be skipped. */ static void TryReuseForeignKey(Oid oldId, Constraint *con) { HeapTuple tup; Datum adatum; ArrayType *arr; Oid *rawarr; int numkeys; int i; Assert(con->contype == CONSTR_FOREIGN); Assert(con->old_conpfeqop == NIL); /* already prepared this node */ tup = SearchSysCache1(CONSTROID, ObjectIdGetDatum(oldId)); if (!HeapTupleIsValid(tup)) /* should not happen */ elog(ERROR, "cache lookup failed for constraint %u", oldId); adatum = SysCacheGetAttrNotNull(CONSTROID, tup, Anum_pg_constraint_conpfeqop); arr = DatumGetArrayTypeP(adatum); /* ensure not toasted */ numkeys = ARR_DIMS(arr)[0]; /* test follows the one in ri_FetchConstraintInfo() */ if (ARR_NDIM(arr) != 1 || ARR_HASNULL(arr) || ARR_ELEMTYPE(arr) != OIDOID) elog(ERROR, "conpfeqop is not a 1-D Oid array"); rawarr = (Oid *) ARR_DATA_PTR(arr); /* stash a List of the operator Oids in our Constraint node */ for (i = 0; i < numkeys; i++) con->old_conpfeqop = lappend_oid(con->old_conpfeqop, rawarr[i]); ReleaseSysCache(tup); } /* * ALTER COLUMN .. OPTIONS ( ... ) * * Returns the address of the modified column */ static ObjectAddress ATExecAlterColumnGenericOptions(Relation rel, const char *colName, List *options, LOCKMODE lockmode) { Relation ftrel; Relation attrel; ForeignServer *server; ForeignDataWrapper *fdw; HeapTuple tuple; HeapTuple newtuple; bool isnull; Datum repl_val[Natts_pg_attribute]; bool repl_null[Natts_pg_attribute]; bool repl_repl[Natts_pg_attribute]; Datum datum; Form_pg_foreign_table fttableform; Form_pg_attribute atttableform; AttrNumber attnum; ObjectAddress address; if (options == NIL) return InvalidObjectAddress; /* First, determine FDW validator associated to the foreign table. */ ftrel = table_open(ForeignTableRelationId, AccessShareLock); tuple = SearchSysCache1(FOREIGNTABLEREL, ObjectIdGetDatum(rel->rd_id)); if (!HeapTupleIsValid(tuple)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_OBJECT), errmsg("foreign table \"%s\" does not exist", RelationGetRelationName(rel)))); fttableform = (Form_pg_foreign_table) GETSTRUCT(tuple); server = GetForeignServer(fttableform->ftserver); fdw = GetForeignDataWrapper(server->fdwid); table_close(ftrel, AccessShareLock); ReleaseSysCache(tuple); attrel = table_open(AttributeRelationId, RowExclusiveLock); tuple = SearchSysCacheAttName(RelationGetRelid(rel), colName); if (!HeapTupleIsValid(tuple)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" of relation \"%s\" does not exist", colName, RelationGetRelationName(rel)))); /* Prevent them from altering a system attribute */ atttableform = (Form_pg_attribute) GETSTRUCT(tuple); attnum = atttableform->attnum; if (attnum <= 0) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter system column \"%s\"", colName))); /* Initialize buffers for new tuple values */ memset(repl_val, 0, sizeof(repl_val)); memset(repl_null, false, sizeof(repl_null)); memset(repl_repl, false, sizeof(repl_repl)); /* Extract the current options */ datum = SysCacheGetAttr(ATTNAME, tuple, Anum_pg_attribute_attfdwoptions, &isnull); if (isnull) datum = PointerGetDatum(NULL); /* Transform the options */ datum = transformGenericOptions(AttributeRelationId, datum, options, fdw->fdwvalidator); if (DatumGetPointer(datum) != NULL) repl_val[Anum_pg_attribute_attfdwoptions - 1] = datum; else repl_null[Anum_pg_attribute_attfdwoptions - 1] = true; repl_repl[Anum_pg_attribute_attfdwoptions - 1] = true; /* Everything looks good - update the tuple */ newtuple = heap_modify_tuple(tuple, RelationGetDescr(attrel), repl_val, repl_null, repl_repl); CatalogTupleUpdate(attrel, &newtuple->t_self, newtuple); InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), atttableform->attnum); ObjectAddressSubSet(address, RelationRelationId, RelationGetRelid(rel), attnum); ReleaseSysCache(tuple); table_close(attrel, RowExclusiveLock); heap_freetuple(newtuple); return address; } /* * ALTER TABLE OWNER * * recursing is true if we are recursing from a table to its indexes, * sequences, or toast table. We don't allow the ownership of those things to * be changed separately from the parent table. Also, we can skip permission * checks (this is necessary not just an optimization, else we'd fail to * handle toast tables properly). * * recursing is also true if ALTER TYPE OWNER is calling us to fix up a * free-standing composite type. */ void ATExecChangeOwner(Oid relationOid, Oid newOwnerId, bool recursing, LOCKMODE lockmode) { Relation target_rel; Relation class_rel; HeapTuple tuple; Form_pg_class tuple_class; /* * Get exclusive lock till end of transaction on the target table. Use * relation_open so that we can work on indexes and sequences. */ target_rel = relation_open(relationOid, lockmode); /* Get its pg_class tuple, too */ class_rel = table_open(RelationRelationId, RowExclusiveLock); tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relationOid)); if (!HeapTupleIsValid(tuple)) elog(ERROR, "cache lookup failed for relation %u", relationOid); tuple_class = (Form_pg_class) GETSTRUCT(tuple); /* Can we change the ownership of this tuple? */ switch (tuple_class->relkind) { case RELKIND_RELATION: case RELKIND_VIEW: case RELKIND_MATVIEW: case RELKIND_FOREIGN_TABLE: case RELKIND_PARTITIONED_TABLE: case RELKIND_PROPGRAPH: /* ok to change owner */ break; case RELKIND_INDEX: if (!recursing) { /* * Because ALTER INDEX OWNER used to be allowed, and in fact * is generated by old versions of pg_dump, we give a warning * and do nothing rather than erroring out. Also, to avoid * unnecessary chatter while restoring those old dumps, say * nothing at all if the command would be a no-op anyway. */ if (tuple_class->relowner != newOwnerId) ereport(WARNING, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot change owner of index \"%s\"", NameStr(tuple_class->relname)), errhint("Change the ownership of the index's table instead."))); /* quick hack to exit via the no-op path */ newOwnerId = tuple_class->relowner; } break; case RELKIND_PARTITIONED_INDEX: if (recursing) break; ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot change owner of index \"%s\"", NameStr(tuple_class->relname)), errhint("Change the ownership of the index's table instead."))); break; case RELKIND_SEQUENCE: if (!recursing && tuple_class->relowner != newOwnerId) { /* if it's an owned sequence, disallow changing it by itself */ Oid tableId; int32 colId; if (sequenceIsOwned(relationOid, DEPENDENCY_AUTO, &tableId, &colId) || sequenceIsOwned(relationOid, DEPENDENCY_INTERNAL, &tableId, &colId)) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot change owner of sequence \"%s\"", NameStr(tuple_class->relname)), errdetail("Sequence \"%s\" is linked to table \"%s\".", NameStr(tuple_class->relname), get_rel_name(tableId)))); } break; case RELKIND_COMPOSITE_TYPE: if (recursing) break; ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is a composite type", NameStr(tuple_class->relname)), /* translator: %s is an SQL ALTER command */ errhint("Use %s instead.", "ALTER TYPE"))); break; case RELKIND_TOASTVALUE: if (recursing) break; pg_fallthrough; default: ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot change owner of relation \"%s\"", NameStr(tuple_class->relname)), errdetail_relkind_not_supported(tuple_class->relkind))); } /* * If the new owner is the same as the existing owner, consider the * command to have succeeded. This is for dump restoration purposes. */ if (tuple_class->relowner != newOwnerId) { Datum repl_val[Natts_pg_class]; bool repl_null[Natts_pg_class]; bool repl_repl[Natts_pg_class]; Acl *newAcl; Datum aclDatum; bool isNull; HeapTuple newtuple; /* skip permission checks when recursing to index or toast table */ if (!recursing) { /* Superusers can always do it */ if (!superuser()) { Oid namespaceOid = tuple_class->relnamespace; AclResult aclresult; /* Otherwise, must be owner of the existing object */ if (!object_ownercheck(RelationRelationId, relationOid, GetUserId())) aclcheck_error(ACLCHECK_NOT_OWNER, get_relkind_objtype(get_rel_relkind(relationOid)), RelationGetRelationName(target_rel)); /* Must be able to become new owner */ check_can_set_role(GetUserId(), newOwnerId); /* New owner must have CREATE privilege on namespace */ aclresult = object_aclcheck(NamespaceRelationId, namespaceOid, newOwnerId, ACL_CREATE); if (aclresult != ACLCHECK_OK) aclcheck_error(aclresult, OBJECT_SCHEMA, get_namespace_name(namespaceOid)); } } memset(repl_null, false, sizeof(repl_null)); memset(repl_repl, false, sizeof(repl_repl)); repl_repl[Anum_pg_class_relowner - 1] = true; repl_val[Anum_pg_class_relowner - 1] = ObjectIdGetDatum(newOwnerId); /* * Determine the modified ACL for the new owner. This is only * necessary when the ACL is non-null. */ aclDatum = SysCacheGetAttr(RELOID, tuple, Anum_pg_class_relacl, &isNull); if (!isNull) { newAcl = aclnewowner(DatumGetAclP(aclDatum), tuple_class->relowner, newOwnerId); repl_repl[Anum_pg_class_relacl - 1] = true; repl_val[Anum_pg_class_relacl - 1] = PointerGetDatum(newAcl); } newtuple = heap_modify_tuple(tuple, RelationGetDescr(class_rel), repl_val, repl_null, repl_repl); CatalogTupleUpdate(class_rel, &newtuple->t_self, newtuple); heap_freetuple(newtuple); /* * We must similarly update any per-column ACLs to reflect the new * owner; for neatness reasons that's split out as a subroutine. */ change_owner_fix_column_acls(relationOid, tuple_class->relowner, newOwnerId); /* * Update owner dependency reference, if any. A composite type has * none, because it's tracked for the pg_type entry instead of here; * indexes and TOAST tables don't have their own entries either. */ if (tuple_class->relkind != RELKIND_COMPOSITE_TYPE && tuple_class->relkind != RELKIND_INDEX && tuple_class->relkind != RELKIND_PARTITIONED_INDEX && tuple_class->relkind != RELKIND_TOASTVALUE) changeDependencyOnOwner(RelationRelationId, relationOid, newOwnerId); /* * Also change the ownership of the table's row type, if it has one */ if (OidIsValid(tuple_class->reltype)) AlterTypeOwnerInternal(tuple_class->reltype, newOwnerId); /* * If we are operating on a table or materialized view, also change * the ownership of any indexes and sequences that belong to the * relation, as well as its toast table (if it has one). */ if (tuple_class->relkind == RELKIND_RELATION || tuple_class->relkind == RELKIND_PARTITIONED_TABLE || tuple_class->relkind == RELKIND_MATVIEW || tuple_class->relkind == RELKIND_TOASTVALUE) { List *index_oid_list; ListCell *i; /* Find all the indexes belonging to this relation */ index_oid_list = RelationGetIndexList(target_rel); /* For each index, recursively change its ownership */ foreach(i, index_oid_list) ATExecChangeOwner(lfirst_oid(i), newOwnerId, true, lockmode); list_free(index_oid_list); } /* If it has a toast table, recurse to change its ownership */ if (tuple_class->reltoastrelid != InvalidOid) ATExecChangeOwner(tuple_class->reltoastrelid, newOwnerId, true, lockmode); /* If it has dependent sequences, recurse to change them too */ change_owner_recurse_to_sequences(relationOid, newOwnerId, lockmode); } InvokeObjectPostAlterHook(RelationRelationId, relationOid, 0); ReleaseSysCache(tuple); table_close(class_rel, RowExclusiveLock); relation_close(target_rel, NoLock); } /* * change_owner_fix_column_acls * * Helper function for ATExecChangeOwner. Scan the columns of the table * and fix any non-null column ACLs to reflect the new owner. */ static void change_owner_fix_column_acls(Oid relationOid, Oid oldOwnerId, Oid newOwnerId) { Relation attRelation; SysScanDesc scan; ScanKeyData key[1]; HeapTuple attributeTuple; attRelation = table_open(AttributeRelationId, RowExclusiveLock); ScanKeyInit(&key[0], Anum_pg_attribute_attrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(relationOid)); scan = systable_beginscan(attRelation, AttributeRelidNumIndexId, true, NULL, 1, key); while (HeapTupleIsValid(attributeTuple = systable_getnext(scan))) { Form_pg_attribute att = (Form_pg_attribute) GETSTRUCT(attributeTuple); Datum repl_val[Natts_pg_attribute]; bool repl_null[Natts_pg_attribute]; bool repl_repl[Natts_pg_attribute]; Acl *newAcl; Datum aclDatum; bool isNull; HeapTuple newtuple; /* Ignore dropped columns */ if (att->attisdropped) continue; aclDatum = heap_getattr(attributeTuple, Anum_pg_attribute_attacl, RelationGetDescr(attRelation), &isNull); /* Null ACLs do not require changes */ if (isNull) continue; memset(repl_null, false, sizeof(repl_null)); memset(repl_repl, false, sizeof(repl_repl)); newAcl = aclnewowner(DatumGetAclP(aclDatum), oldOwnerId, newOwnerId); repl_repl[Anum_pg_attribute_attacl - 1] = true; repl_val[Anum_pg_attribute_attacl - 1] = PointerGetDatum(newAcl); newtuple = heap_modify_tuple(attributeTuple, RelationGetDescr(attRelation), repl_val, repl_null, repl_repl); CatalogTupleUpdate(attRelation, &newtuple->t_self, newtuple); heap_freetuple(newtuple); } systable_endscan(scan); table_close(attRelation, RowExclusiveLock); } /* * change_owner_recurse_to_sequences * * Helper function for ATExecChangeOwner. Examines pg_depend searching * for sequences that are dependent on serial columns, and changes their * ownership. */ static void change_owner_recurse_to_sequences(Oid relationOid, Oid newOwnerId, LOCKMODE lockmode) { Relation depRel; SysScanDesc scan; ScanKeyData key[2]; HeapTuple tup; /* * SERIAL sequences are those having an auto dependency on one of the * table's columns (we don't care *which* column, exactly). */ depRel = table_open(DependRelationId, AccessShareLock); ScanKeyInit(&key[0], Anum_pg_depend_refclassid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationRelationId)); ScanKeyInit(&key[1], Anum_pg_depend_refobjid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(relationOid)); /* we leave refobjsubid unspecified */ scan = systable_beginscan(depRel, DependReferenceIndexId, true, NULL, 2, key); while (HeapTupleIsValid(tup = systable_getnext(scan))) { Form_pg_depend depForm = (Form_pg_depend) GETSTRUCT(tup); Relation seqRel; /* skip dependencies other than auto dependencies on columns */ if (depForm->refobjsubid == 0 || depForm->classid != RelationRelationId || depForm->objsubid != 0 || !(depForm->deptype == DEPENDENCY_AUTO || depForm->deptype == DEPENDENCY_INTERNAL)) continue; /* Use relation_open just in case it's an index */ seqRel = relation_open(depForm->objid, lockmode); /* skip non-sequence relations */ if (RelationGetForm(seqRel)->relkind != RELKIND_SEQUENCE) { /* No need to keep the lock */ relation_close(seqRel, lockmode); continue; } /* We don't need to close the sequence while we alter it. */ ATExecChangeOwner(depForm->objid, newOwnerId, true, lockmode); /* Now we can close it. Keep the lock till end of transaction. */ relation_close(seqRel, NoLock); } systable_endscan(scan); relation_close(depRel, AccessShareLock); } /* * ALTER TABLE CLUSTER ON * * The only thing we have to do is to change the indisclustered bits. * * Return the address of the new clustering index. */ static ObjectAddress ATExecClusterOn(Relation rel, const char *indexName, LOCKMODE lockmode) { Oid indexOid; ObjectAddress address; indexOid = get_relname_relid(indexName, rel->rd_rel->relnamespace); if (!OidIsValid(indexOid)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_OBJECT), errmsg("index \"%s\" for table \"%s\" does not exist", indexName, RelationGetRelationName(rel)))); /* Check index is valid to cluster on */ check_index_is_clusterable(rel, indexOid, lockmode); /* And do the work */ mark_index_clustered(rel, indexOid, false); ObjectAddressSet(address, RelationRelationId, indexOid); return address; } /* * ALTER TABLE SET WITHOUT CLUSTER * * We have to find any indexes on the table that have indisclustered bit * set and turn it off. */ static void ATExecDropCluster(Relation rel, LOCKMODE lockmode) { mark_index_clustered(rel, InvalidOid, false); } /* * Preparation phase for SET ACCESS METHOD * * Check that the access method exists and determine whether a change is * actually needed. */ static void ATPrepSetAccessMethod(AlteredTableInfo *tab, Relation rel, const char *amname) { Oid amoid; /* * Look up the access method name and check that it differs from the * table's current AM. If DEFAULT was specified for a partitioned table * (amname is NULL), set it to InvalidOid to reset the catalogued AM. */ if (amname != NULL) amoid = get_table_am_oid(amname, false); else if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) amoid = InvalidOid; else amoid = get_table_am_oid(default_table_access_method, false); /* if it's a match, phase 3 doesn't need to do anything */ if (rel->rd_rel->relam == amoid) return; /* Save info for Phase 3 to do the real work */ tab->rewrite |= AT_REWRITE_ACCESS_METHOD; tab->newAccessMethod = amoid; tab->chgAccessMethod = true; } /* * Special handling of ALTER TABLE SET ACCESS METHOD for relations with no * storage that have an interest in preserving AM. * * Since these have no storage, setting the access method is a catalog only * operation. */ static void ATExecSetAccessMethodNoStorage(Relation rel, Oid newAccessMethodId) { Relation pg_class; Oid oldAccessMethodId; HeapTuple tuple; Form_pg_class rd_rel; Oid reloid = RelationGetRelid(rel); /* * Shouldn't be called on relations having storage; these are processed in * phase 3. */ Assert(!RELKIND_HAS_STORAGE(rel->rd_rel->relkind)); /* Get a modifiable copy of the relation's pg_class row. */ pg_class = table_open(RelationRelationId, RowExclusiveLock); tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(reloid)); if (!HeapTupleIsValid(tuple)) elog(ERROR, "cache lookup failed for relation %u", reloid); rd_rel = (Form_pg_class) GETSTRUCT(tuple); /* Update the pg_class row. */ oldAccessMethodId = rd_rel->relam; rd_rel->relam = newAccessMethodId; /* Leave if no update required */ if (rd_rel->relam == oldAccessMethodId) { heap_freetuple(tuple); table_close(pg_class, RowExclusiveLock); return; } CatalogTupleUpdate(pg_class, &tuple->t_self, tuple); /* * Update the dependency on the new access method. No dependency is added * if the new access method is InvalidOid (default case). Be very careful * that this has to compare the previous value stored in pg_class with the * new one. */ if (!OidIsValid(oldAccessMethodId) && OidIsValid(rd_rel->relam)) { ObjectAddress relobj, referenced; /* * New access method is defined and there was no dependency * previously, so record a new one. */ ObjectAddressSet(relobj, RelationRelationId, reloid); ObjectAddressSet(referenced, AccessMethodRelationId, rd_rel->relam); recordDependencyOn(&relobj, &referenced, DEPENDENCY_NORMAL); } else if (OidIsValid(oldAccessMethodId) && !OidIsValid(rd_rel->relam)) { /* * There was an access method defined, and no new one, so just remove * the existing dependency. */ deleteDependencyRecordsForClass(RelationRelationId, reloid, AccessMethodRelationId, DEPENDENCY_NORMAL); } else { Assert(OidIsValid(oldAccessMethodId) && OidIsValid(rd_rel->relam)); /* Both are valid, so update the dependency */ changeDependencyFor(RelationRelationId, reloid, AccessMethodRelationId, oldAccessMethodId, rd_rel->relam); } /* make the relam and dependency changes visible */ CommandCounterIncrement(); InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), 0); heap_freetuple(tuple); table_close(pg_class, RowExclusiveLock); } /* * ALTER TABLE SET TABLESPACE */ static void ATPrepSetTableSpace(AlteredTableInfo *tab, Relation rel, const char *tablespacename, LOCKMODE lockmode) { Oid tablespaceId; /* Check that the tablespace exists */ tablespaceId = get_tablespace_oid(tablespacename, false); /* Check permissions except when moving to database's default */ if (OidIsValid(tablespaceId) && tablespaceId != MyDatabaseTableSpace) { AclResult aclresult; aclresult = object_aclcheck(TableSpaceRelationId, tablespaceId, GetUserId(), ACL_CREATE); if (aclresult != ACLCHECK_OK) aclcheck_error(aclresult, OBJECT_TABLESPACE, tablespacename); } /* Save info for Phase 3 to do the real work */ if (OidIsValid(tab->newTableSpace)) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("cannot have multiple SET TABLESPACE subcommands"))); tab->newTableSpace = tablespaceId; } /* * Set, reset, or replace reloptions. */ static void ATExecSetRelOptions(Relation rel, List *defList, AlterTableType operation, LOCKMODE lockmode) { Oid relid; Relation pgclass; HeapTuple tuple; HeapTuple newtuple; Datum datum; Datum newOptions; Datum repl_val[Natts_pg_class]; bool repl_null[Natts_pg_class]; bool repl_repl[Natts_pg_class]; const char *const validnsps[] = HEAP_RELOPT_NAMESPACES; if (defList == NIL && operation != AT_ReplaceRelOptions) return; /* nothing to do */ pgclass = table_open(RelationRelationId, RowExclusiveLock); /* Fetch heap tuple */ relid = RelationGetRelid(rel); tuple = SearchSysCacheLocked1(RELOID, ObjectIdGetDatum(relid)); if (!HeapTupleIsValid(tuple)) elog(ERROR, "cache lookup failed for relation %u", relid); if (operation == AT_ReplaceRelOptions) { /* * If we're supposed to replace the reloptions list, we just pretend * there were none before. */ datum = (Datum) 0; } else { bool isnull; /* Get the old reloptions */ datum = SysCacheGetAttr(RELOID, tuple, Anum_pg_class_reloptions, &isnull); if (isnull) datum = (Datum) 0; } /* Generate new proposed reloptions (text array) */ newOptions = transformRelOptions(datum, defList, NULL, validnsps, false, operation == AT_ResetRelOptions); /* Validate */ switch (rel->rd_rel->relkind) { case RELKIND_RELATION: case RELKIND_MATVIEW: (void) heap_reloptions(rel->rd_rel->relkind, newOptions, true); break; case RELKIND_PARTITIONED_TABLE: (void) partitioned_table_reloptions(newOptions, true); break; case RELKIND_VIEW: (void) view_reloptions(newOptions, true); break; case RELKIND_INDEX: case RELKIND_PARTITIONED_INDEX: (void) index_reloptions(rel->rd_indam->amoptions, newOptions, true); break; case RELKIND_TOASTVALUE: /* fall through to error -- shouldn't ever get here */ default: ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot set options for relation \"%s\"", RelationGetRelationName(rel)), errdetail_relkind_not_supported(rel->rd_rel->relkind))); break; } /* Special-case validation of view options */ if (rel->rd_rel->relkind == RELKIND_VIEW) { Query *view_query = get_view_query(rel); List *view_options = untransformRelOptions(newOptions); ListCell *cell; bool check_option = false; foreach(cell, view_options) { DefElem *defel = (DefElem *) lfirst(cell); if (strcmp(defel->defname, "check_option") == 0) check_option = true; } /* * If the check option is specified, look to see if the view is * actually auto-updatable or not. */ if (check_option) { const char *view_updatable_error = view_query_is_auto_updatable(view_query, true); if (view_updatable_error) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("WITH CHECK OPTION is supported only on automatically updatable views"), errhint("%s", _(view_updatable_error)))); } } /* * All we need do here is update the pg_class row; the new options will be * propagated into relcaches during post-commit cache inval. */ memset(repl_val, 0, sizeof(repl_val)); memset(repl_null, false, sizeof(repl_null)); memset(repl_repl, false, sizeof(repl_repl)); if (newOptions != (Datum) 0) repl_val[Anum_pg_class_reloptions - 1] = newOptions; else repl_null[Anum_pg_class_reloptions - 1] = true; repl_repl[Anum_pg_class_reloptions - 1] = true; newtuple = heap_modify_tuple(tuple, RelationGetDescr(pgclass), repl_val, repl_null, repl_repl); CatalogTupleUpdate(pgclass, &newtuple->t_self, newtuple); UnlockTuple(pgclass, &tuple->t_self, InplaceUpdateTupleLock); InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), 0); heap_freetuple(newtuple); ReleaseSysCache(tuple); /* repeat the whole exercise for the toast table, if there's one */ if (OidIsValid(rel->rd_rel->reltoastrelid)) { Relation toastrel; Oid toastid = rel->rd_rel->reltoastrelid; toastrel = table_open(toastid, lockmode); /* Fetch heap tuple */ tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(toastid)); if (!HeapTupleIsValid(tuple)) elog(ERROR, "cache lookup failed for relation %u", toastid); if (operation == AT_ReplaceRelOptions) { /* * If we're supposed to replace the reloptions list, we just * pretend there were none before. */ datum = (Datum) 0; } else { bool isnull; /* Get the old reloptions */ datum = SysCacheGetAttr(RELOID, tuple, Anum_pg_class_reloptions, &isnull); if (isnull) datum = (Datum) 0; } newOptions = transformRelOptions(datum, defList, "toast", validnsps, false, operation == AT_ResetRelOptions); (void) heap_reloptions(RELKIND_TOASTVALUE, newOptions, true); memset(repl_val, 0, sizeof(repl_val)); memset(repl_null, false, sizeof(repl_null)); memset(repl_repl, false, sizeof(repl_repl)); if (newOptions != (Datum) 0) repl_val[Anum_pg_class_reloptions - 1] = newOptions; else repl_null[Anum_pg_class_reloptions - 1] = true; repl_repl[Anum_pg_class_reloptions - 1] = true; newtuple = heap_modify_tuple(tuple, RelationGetDescr(pgclass), repl_val, repl_null, repl_repl); CatalogTupleUpdate(pgclass, &newtuple->t_self, newtuple); InvokeObjectPostAlterHookArg(RelationRelationId, RelationGetRelid(toastrel), 0, InvalidOid, true); heap_freetuple(newtuple); ReleaseSysCache(tuple); table_close(toastrel, NoLock); } table_close(pgclass, RowExclusiveLock); } /* * Execute ALTER TABLE SET TABLESPACE for cases where there is no tuple * rewriting to be done, so we just want to copy the data as fast as possible. */ static void ATExecSetTableSpace(Oid tableOid, Oid newTableSpace, LOCKMODE lockmode) { Relation rel; Oid reltoastrelid; RelFileNumber newrelfilenumber; RelFileLocator newrlocator; List *reltoastidxids = NIL; ListCell *lc; /* * Need lock here in case we are recursing to toast table or index */ rel = relation_open(tableOid, lockmode); /* Check first if relation can be moved to new tablespace */ if (!CheckRelationTableSpaceMove(rel, newTableSpace)) { InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), 0); relation_close(rel, NoLock); return; } reltoastrelid = rel->rd_rel->reltoastrelid; /* Fetch the list of indexes on toast relation if necessary */ if (OidIsValid(reltoastrelid)) { Relation toastRel = relation_open(reltoastrelid, lockmode); reltoastidxids = RelationGetIndexList(toastRel); relation_close(toastRel, lockmode); } /* * Relfilenumbers are not unique in databases across tablespaces, so we * need to allocate a new one in the new tablespace. */ newrelfilenumber = GetNewRelFileNumber(newTableSpace, NULL, rel->rd_rel->relpersistence); /* Open old and new relation */ newrlocator = rel->rd_locator; newrlocator.relNumber = newrelfilenumber; newrlocator.spcOid = newTableSpace; /* hand off to AM to actually create new rel storage and copy the data */ if (rel->rd_rel->relkind == RELKIND_INDEX) { index_copy_data(rel, newrlocator); } else { Assert(RELKIND_HAS_TABLE_AM(rel->rd_rel->relkind)); table_relation_copy_data(rel, &newrlocator); } /* * Update the pg_class row. * * NB: This wouldn't work if ATExecSetTableSpace() were allowed to be * executed on pg_class or its indexes (the above copy wouldn't contain * the updated pg_class entry), but that's forbidden with * CheckRelationTableSpaceMove(). */ SetRelationTableSpace(rel, newTableSpace, newrelfilenumber); InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), 0); RelationAssumeNewRelfilelocator(rel); relation_close(rel, NoLock); /* Make sure the reltablespace change is visible */ CommandCounterIncrement(); /* Move associated toast relation and/or indexes, too */ if (OidIsValid(reltoastrelid)) ATExecSetTableSpace(reltoastrelid, newTableSpace, lockmode); foreach(lc, reltoastidxids) ATExecSetTableSpace(lfirst_oid(lc), newTableSpace, lockmode); /* Clean up */ list_free(reltoastidxids); } /* * Special handling of ALTER TABLE SET TABLESPACE for relations with no * storage that have an interest in preserving tablespace. * * Since these have no storage the tablespace can be updated with a simple * metadata only operation to update the tablespace. */ static void ATExecSetTableSpaceNoStorage(Relation rel, Oid newTableSpace) { /* * Shouldn't be called on relations having storage; these are processed in * phase 3. */ Assert(!RELKIND_HAS_STORAGE(rel->rd_rel->relkind)); /* check if relation can be moved to its new tablespace */ if (!CheckRelationTableSpaceMove(rel, newTableSpace)) { InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), 0); return; } /* Update can be done, so change reltablespace */ SetRelationTableSpace(rel, newTableSpace, InvalidOid); InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), 0); /* Make sure the reltablespace change is visible */ CommandCounterIncrement(); } /* * Alter Table ALL ... SET TABLESPACE * * Allows a user to move all objects of some type in a given tablespace in the * current database to another tablespace. Objects can be chosen based on the * owner of the object also, to allow users to move only their objects. * The user must have CREATE rights on the new tablespace, as usual. The main * permissions handling is done by the lower-level table move function. * * All to-be-moved objects are locked first. If NOWAIT is specified and the * lock can't be acquired then we ereport(ERROR). */ Oid AlterTableMoveAll(AlterTableMoveAllStmt *stmt) { List *relations = NIL; ListCell *l; ScanKeyData key[1]; Relation rel; TableScanDesc scan; HeapTuple tuple; Oid orig_tablespaceoid; Oid new_tablespaceoid; List *role_oids = roleSpecsToIds(stmt->roles); /* Ensure we were not asked to move something we can't */ if (stmt->objtype != OBJECT_TABLE && stmt->objtype != OBJECT_INDEX && stmt->objtype != OBJECT_MATVIEW) ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("only tables, indexes, and materialized views exist in tablespaces"))); /* Get the orig and new tablespace OIDs */ orig_tablespaceoid = get_tablespace_oid(stmt->orig_tablespacename, false); new_tablespaceoid = get_tablespace_oid(stmt->new_tablespacename, false); /* Can't move shared relations in to or out of pg_global */ /* This is also checked by ATExecSetTableSpace, but nice to stop earlier */ if (orig_tablespaceoid == GLOBALTABLESPACE_OID || new_tablespaceoid == GLOBALTABLESPACE_OID) ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("cannot move relations in to or out of pg_global tablespace"))); /* * Must have CREATE rights on the new tablespace, unless it is the * database default tablespace (which all users implicitly have CREATE * rights on). */ if (OidIsValid(new_tablespaceoid) && new_tablespaceoid != MyDatabaseTableSpace) { AclResult aclresult; aclresult = object_aclcheck(TableSpaceRelationId, new_tablespaceoid, GetUserId(), ACL_CREATE); if (aclresult != ACLCHECK_OK) aclcheck_error(aclresult, OBJECT_TABLESPACE, get_tablespace_name(new_tablespaceoid)); } /* * Now that the checks are done, check if we should set either to * InvalidOid because it is our database's default tablespace. */ if (orig_tablespaceoid == MyDatabaseTableSpace) orig_tablespaceoid = InvalidOid; if (new_tablespaceoid == MyDatabaseTableSpace) new_tablespaceoid = InvalidOid; /* no-op */ if (orig_tablespaceoid == new_tablespaceoid) return new_tablespaceoid; /* * Walk the list of objects in the tablespace and move them. This will * only find objects in our database, of course. */ ScanKeyInit(&key[0], Anum_pg_class_reltablespace, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(orig_tablespaceoid)); rel = table_open(RelationRelationId, AccessShareLock); scan = table_beginscan_catalog(rel, 1, key); while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL) { Form_pg_class relForm = (Form_pg_class) GETSTRUCT(tuple); Oid relOid = relForm->oid; /* * Do not move objects in pg_catalog as part of this, if an admin * really wishes to do so, they can issue the individual ALTER * commands directly. * * Also, explicitly avoid any shared tables, temp tables, TOAST (TOAST * will be moved with the main table). * * Conflict log tables are system-managed for logical replication and * cannot be altered directly, so skip them as well; otherwise a * single such table in the source tablespace would abort the whole * bulk move. */ if (IsCatalogNamespace(relForm->relnamespace) || relForm->relisshared || isAnyTempNamespace(relForm->relnamespace) || IsToastNamespace(relForm->relnamespace) || IsConflictLogTableNamespace(relForm->relnamespace)) continue; /* Only move the object type requested */ if ((stmt->objtype == OBJECT_TABLE && relForm->relkind != RELKIND_RELATION && relForm->relkind != RELKIND_PARTITIONED_TABLE) || (stmt->objtype == OBJECT_INDEX && relForm->relkind != RELKIND_INDEX && relForm->relkind != RELKIND_PARTITIONED_INDEX) || (stmt->objtype == OBJECT_MATVIEW && relForm->relkind != RELKIND_MATVIEW)) continue; /* Check if we are only moving objects owned by certain roles */ if (role_oids != NIL && !list_member_oid(role_oids, relForm->relowner)) continue; /* * Handle permissions-checking here since we are locking the tables * and also to avoid doing a bunch of work only to fail part-way. Note * that permissions will also be checked by AlterTableInternal(). * * Caller must be considered an owner on the table to move it. */ if (!object_ownercheck(RelationRelationId, relOid, GetUserId())) aclcheck_error(ACLCHECK_NOT_OWNER, get_relkind_objtype(get_rel_relkind(relOid)), NameStr(relForm->relname)); if (stmt->nowait && !ConditionalLockRelationOid(relOid, AccessExclusiveLock)) ereport(ERROR, (errcode(ERRCODE_OBJECT_IN_USE), errmsg("aborting because lock on relation \"%s.%s\" is not available", get_namespace_name(relForm->relnamespace), NameStr(relForm->relname)))); else LockRelationOid(relOid, AccessExclusiveLock); /* Add to our list of objects to move */ relations = lappend_oid(relations, relOid); } table_endscan(scan); table_close(rel, AccessShareLock); if (relations == NIL) ereport(NOTICE, (errcode(ERRCODE_NO_DATA_FOUND), errmsg("no matching relations in tablespace \"%s\" found", orig_tablespaceoid == InvalidOid ? "(database default)" : get_tablespace_name(orig_tablespaceoid)))); /* Everything is locked, loop through and move all of the relations. */ foreach(l, relations) { List *cmds = NIL; AlterTableCmd *cmd = makeNode(AlterTableCmd); cmd->subtype = AT_SetTableSpace; cmd->name = stmt->new_tablespacename; cmds = lappend(cmds, cmd); EventTriggerAlterTableStart((Node *) stmt); /* OID is set by AlterTableInternal */ AlterTableInternal(lfirst_oid(l), cmds, false); EventTriggerAlterTableEnd(); } return new_tablespaceoid; } static void index_copy_data(Relation rel, RelFileLocator newrlocator) { SMgrRelation dstrel; /* * Since we copy the file directly without looking at the shared buffers, * we'd better first flush out any pages of the source relation that are * in shared buffers. We assume no new changes will be made while we are * holding exclusive lock on the rel. */ FlushRelationBuffers(rel); /* * Create and copy all forks of the relation, and schedule unlinking of * old physical files. * * NOTE: any conflict in relfilenumber value will be caught in * RelationCreateStorage(). */ dstrel = RelationCreateStorage(newrlocator, rel->rd_rel->relpersistence, true); /* copy main fork */ RelationCopyStorage(RelationGetSmgr(rel), dstrel, MAIN_FORKNUM, rel->rd_rel->relpersistence); /* copy those extra forks that exist */ for (ForkNumber forkNum = MAIN_FORKNUM + 1; forkNum <= MAX_FORKNUM; forkNum++) { if (smgrexists(RelationGetSmgr(rel), forkNum)) { smgrcreate(dstrel, forkNum, false); /* * WAL log creation if the relation is persistent, or this is the * init fork of an unlogged relation. */ if (RelationIsPermanent(rel) || (rel->rd_rel->relpersistence == RELPERSISTENCE_UNLOGGED && forkNum == INIT_FORKNUM)) log_smgrcreate(&newrlocator, forkNum); RelationCopyStorage(RelationGetSmgr(rel), dstrel, forkNum, rel->rd_rel->relpersistence); } } /* drop old relation, and close new one */ RelationDropStorage(rel); smgrclose(dstrel); } /* * ALTER TABLE ENABLE/DISABLE TRIGGER * * We just pass this off to trigger.c. */ static void ATExecEnableDisableTrigger(Relation rel, const char *trigname, char fires_when, bool skip_system, bool recurse, LOCKMODE lockmode) { EnableDisableTrigger(rel, trigname, InvalidOid, fires_when, skip_system, recurse, lockmode); InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), 0); } /* * ALTER TABLE ENABLE/DISABLE RULE * * We just pass this off to rewriteDefine.c. */ static void ATExecEnableDisableRule(Relation rel, const char *rulename, char fires_when, LOCKMODE lockmode) { EnableDisableRule(rel, rulename, fires_when); InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), 0); } /* * Preparation phase of [NO] INHERIT * * Check the relation defined as a child. */ static void ATPrepChangeInherit(Relation child_rel) { if (child_rel->rd_rel->reloftype) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot change inheritance of typed table"))); if (child_rel->rd_rel->relispartition) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot change inheritance of a partition"))); } /* * ALTER TABLE INHERIT * * Return the address of the new parent relation. */ static ObjectAddress ATExecAddInherit(Relation child_rel, RangeVar *parent, LOCKMODE lockmode) { Relation parent_rel; List *children; ObjectAddress address; const char *trigger_name; /* * A self-exclusive lock is needed here. See the similar case in * MergeAttributes() for a full explanation. */ parent_rel = table_openrv(parent, ShareUpdateExclusiveLock); /* * Must be owner of both parent and child -- child was checked by * ATSimplePermissions call in ATPrepCmd */ ATSimplePermissions(AT_AddInherit, parent_rel, ATT_TABLE | ATT_PARTITIONED_TABLE | ATT_FOREIGN_TABLE); /* Permanent rels cannot inherit from temporary ones */ if (parent_rel->rd_rel->relpersistence == RELPERSISTENCE_TEMP && child_rel->rd_rel->relpersistence != RELPERSISTENCE_TEMP) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot inherit from temporary relation \"%s\"", RelationGetRelationName(parent_rel)))); /* If parent rel is temp, it must belong to this session */ if (RELATION_IS_OTHER_TEMP(parent_rel)) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot inherit from temporary relation of another session"))); /* Ditto for the child */ if (RELATION_IS_OTHER_TEMP(child_rel)) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot inherit to temporary relation of another session"))); /* Prevent partitioned tables from becoming inheritance parents */ if (parent_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot inherit from partitioned table \"%s\"", parent->relname))); /* Likewise for partitions */ if (parent_rel->rd_rel->relispartition) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot inherit from a partition"))); /* * Prevent circularity by seeing if proposed parent inherits from child. * (In particular, this disallows making a rel inherit from itself.) * * This is not completely bulletproof because of race conditions: in * multi-level inheritance trees, someone else could concurrently be * making another inheritance link that closes the loop but does not join * either of the rels we have locked. Preventing that seems to require * exclusive locks on the entire inheritance tree, which is a cure worse * than the disease. find_all_inheritors() will cope with circularity * anyway, so don't sweat it too much. * * We use weakest lock we can on child's children, namely AccessShareLock. */ children = find_all_inheritors(RelationGetRelid(child_rel), AccessShareLock, NULL); if (list_member_oid(children, RelationGetRelid(parent_rel))) ereport(ERROR, (errcode(ERRCODE_DUPLICATE_TABLE), errmsg("circular inheritance not allowed"), errdetail("\"%s\" is already a child of \"%s\".", parent->relname, RelationGetRelationName(child_rel)))); /* * If child_rel has row-level triggers with transition tables, we * currently don't allow it to become an inheritance child. See also * prohibitions in ATExecAttachPartition() and CreateTrigger(). */ trigger_name = FindTriggerIncompatibleWithInheritance(child_rel->trigdesc); if (trigger_name != NULL) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("trigger \"%s\" prevents table \"%s\" from becoming an inheritance child", trigger_name, RelationGetRelationName(child_rel)), errdetail("ROW triggers with transition tables are not supported in inheritance hierarchies."))); /* OK to create inheritance */ CreateInheritance(child_rel, parent_rel, false); ObjectAddressSet(address, RelationRelationId, RelationGetRelid(parent_rel)); /* keep our lock on the parent relation until commit */ table_close(parent_rel, NoLock); return address; } /* * CreateInheritance * Catalog manipulation portion of creating inheritance between a child * table and a parent table. * * This verifies that all the columns and check constraints of the parent * appear in the child and that they have the same data types and expressions. * * Common to ATExecAddInherit() and ATExecAttachPartition(). */ static void CreateInheritance(Relation child_rel, Relation parent_rel, bool ispartition) { Relation catalogRelation; SysScanDesc scan; ScanKeyData key; HeapTuple inheritsTuple; int32 inhseqno; /* Note: get RowExclusiveLock because we will write pg_inherits below. */ catalogRelation = table_open(InheritsRelationId, RowExclusiveLock); /* * Check for duplicates in the list of parents, and determine the highest * inhseqno already present; we'll use the next one for the new parent. * Also, if proposed child is a partition, it cannot already be * inheriting. * * Note: we do not reject the case where the child already inherits from * the parent indirectly; CREATE TABLE doesn't reject comparable cases. */ ScanKeyInit(&key, Anum_pg_inherits_inhrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(child_rel))); scan = systable_beginscan(catalogRelation, InheritsRelidSeqnoIndexId, true, NULL, 1, &key); /* inhseqno sequences start at 1 */ inhseqno = 0; while (HeapTupleIsValid(inheritsTuple = systable_getnext(scan))) { Form_pg_inherits inh = (Form_pg_inherits) GETSTRUCT(inheritsTuple); if (inh->inhparent == RelationGetRelid(parent_rel)) ereport(ERROR, (errcode(ERRCODE_DUPLICATE_TABLE), errmsg("relation \"%s\" would be inherited from more than once", RelationGetRelationName(parent_rel)))); if (inh->inhseqno > inhseqno) inhseqno = inh->inhseqno; } systable_endscan(scan); /* Match up the columns and bump attinhcount as needed */ MergeAttributesIntoExisting(child_rel, parent_rel, ispartition); /* Match up the constraints and bump coninhcount as needed */ MergeConstraintsIntoExisting(child_rel, parent_rel); /* * OK, it looks valid. Make the catalog entries that show inheritance. */ StoreCatalogInheritance1(RelationGetRelid(child_rel), RelationGetRelid(parent_rel), inhseqno + 1, catalogRelation, parent_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE); /* Now we're done with pg_inherits */ table_close(catalogRelation, RowExclusiveLock); } /* * Obtain the source-text form of the constraint expression for a check * constraint, given its pg_constraint tuple */ static char * decompile_conbin(HeapTuple contup, TupleDesc tupdesc) { Form_pg_constraint con; bool isnull; Datum attr; Datum expr; con = (Form_pg_constraint) GETSTRUCT(contup); attr = heap_getattr(contup, Anum_pg_constraint_conbin, tupdesc, &isnull); if (isnull) elog(ERROR, "null conbin for constraint %u", con->oid); expr = DirectFunctionCall2(pg_get_expr, attr, ObjectIdGetDatum(con->conrelid)); return TextDatumGetCString(expr); } /* * Determine whether two check constraints are functionally equivalent * * The test we apply is to see whether they reverse-compile to the same * source string. This insulates us from issues like whether attributes * have the same physical column numbers in parent and child relations. * * Note that we ignore enforceability as there are cases where constraints * with differing enforceability are allowed. */ static bool constraints_equivalent(HeapTuple a, HeapTuple b, TupleDesc tupleDesc) { Form_pg_constraint acon = (Form_pg_constraint) GETSTRUCT(a); Form_pg_constraint bcon = (Form_pg_constraint) GETSTRUCT(b); if (acon->condeferrable != bcon->condeferrable || acon->condeferred != bcon->condeferred || strcmp(decompile_conbin(a, tupleDesc), decompile_conbin(b, tupleDesc)) != 0) return false; else return true; } /* * Check columns in child table match up with columns in parent, and increment * their attinhcount. * * Called by CreateInheritance * * Currently all parent columns must be found in child. Missing columns are an * error. One day we might consider creating new columns like CREATE TABLE * does. However, that is widely unpopular --- in the common use case of * partitioned tables it's a foot-gun. * * The data type must match exactly. If the parent column is NOT NULL then * the child must be as well. Defaults are not compared, however. */ static void MergeAttributesIntoExisting(Relation child_rel, Relation parent_rel, bool ispartition) { Relation attrrel; TupleDesc parent_desc; attrrel = table_open(AttributeRelationId, RowExclusiveLock); parent_desc = RelationGetDescr(parent_rel); for (AttrNumber parent_attno = 1; parent_attno <= parent_desc->natts; parent_attno++) { Form_pg_attribute parent_att = TupleDescAttr(parent_desc, parent_attno - 1); char *parent_attname = NameStr(parent_att->attname); HeapTuple tuple; /* Ignore dropped columns in the parent. */ if (parent_att->attisdropped) continue; /* Find same column in child (matching on column name). */ tuple = SearchSysCacheCopyAttName(RelationGetRelid(child_rel), parent_attname); if (HeapTupleIsValid(tuple)) { Form_pg_attribute child_att = (Form_pg_attribute) GETSTRUCT(tuple); if (parent_att->atttypid != child_att->atttypid || parent_att->atttypmod != child_att->atttypmod) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("child table \"%s\" has different type for column \"%s\"", RelationGetRelationName(child_rel), parent_attname))); if (parent_att->attcollation != child_att->attcollation) ereport(ERROR, (errcode(ERRCODE_COLLATION_MISMATCH), errmsg("child table \"%s\" has different collation for column \"%s\"", RelationGetRelationName(child_rel), parent_attname))); /* * If the parent has a not-null constraint that's not NO INHERIT, * make sure the child has one too. * * Other constraints are checked elsewhere. */ if (parent_att->attnotnull && !child_att->attnotnull) { HeapTuple contup; contup = findNotNullConstraintAttnum(RelationGetRelid(parent_rel), parent_att->attnum); if (HeapTupleIsValid(contup) && !((Form_pg_constraint) GETSTRUCT(contup))->connoinherit) ereport(ERROR, errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("column \"%s\" in child table \"%s\" must be marked NOT NULL", parent_attname, RelationGetRelationName(child_rel))); } /* * Child column must be generated if and only if parent column is. */ if (parent_att->attgenerated && !child_att->attgenerated) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("column \"%s\" in child table must be a generated column", parent_attname))); if (child_att->attgenerated && !parent_att->attgenerated) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("column \"%s\" in child table must not be a generated column", parent_attname))); if (parent_att->attgenerated && child_att->attgenerated && child_att->attgenerated != parent_att->attgenerated) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("column \"%s\" inherits from generated column of different kind", parent_attname), errdetail("Parent column is %s, child column is %s.", parent_att->attgenerated == ATTRIBUTE_GENERATED_STORED ? "STORED" : "VIRTUAL", child_att->attgenerated == ATTRIBUTE_GENERATED_STORED ? "STORED" : "VIRTUAL"))); /* * Regular inheritance children are independent enough not to * inherit identity columns. But partitions are integral part of * a partitioned table and inherit identity column. */ if (ispartition) child_att->attidentity = parent_att->attidentity; /* * OK, bump the child column's inheritance count. (If we fail * later on, this change will just roll back.) */ if (pg_add_s16_overflow(child_att->attinhcount, 1, &child_att->attinhcount)) ereport(ERROR, errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED), errmsg("too many inheritance parents")); /* * In case of partitions, we must enforce that value of attislocal * is same in all partitions. (Note: there are only inherited * attributes in partitions) */ if (parent_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) { Assert(child_att->attinhcount == 1); child_att->attislocal = false; } CatalogTupleUpdate(attrrel, &tuple->t_self, tuple); heap_freetuple(tuple); } else { ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("child table is missing column \"%s\"", parent_attname))); } } table_close(attrrel, RowExclusiveLock); } /* * Check constraints in child table match up with constraints in parent, * and increment their coninhcount. * * Constraints that are marked ONLY in the parent are ignored. * * Called by CreateInheritance * * Currently all constraints in parent must be present in the child. One day we * may consider adding new constraints like CREATE TABLE does. * * XXX This is O(N^2) which may be an issue with tables with hundreds of * constraints. As long as tables have more like 10 constraints it shouldn't be * a problem though. Even 100 constraints ought not be the end of the world. * * XXX See MergeWithExistingConstraint too if you change this code. */ static void MergeConstraintsIntoExisting(Relation child_rel, Relation parent_rel) { Relation constraintrel; SysScanDesc parent_scan; ScanKeyData parent_key; HeapTuple parent_tuple; Oid parent_relid = RelationGetRelid(parent_rel); AttrMap *attmap; constraintrel = table_open(ConstraintRelationId, RowExclusiveLock); /* Outer loop scans through the parent's constraint definitions */ ScanKeyInit(&parent_key, Anum_pg_constraint_conrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(parent_relid)); parent_scan = systable_beginscan(constraintrel, ConstraintRelidTypidNameIndexId, true, NULL, 1, &parent_key); attmap = build_attrmap_by_name(RelationGetDescr(parent_rel), RelationGetDescr(child_rel), true); while (HeapTupleIsValid(parent_tuple = systable_getnext(parent_scan))) { Form_pg_constraint parent_con = (Form_pg_constraint) GETSTRUCT(parent_tuple); SysScanDesc child_scan; ScanKeyData child_key; HeapTuple child_tuple; AttrNumber parent_attno; bool found = false; if (parent_con->contype != CONSTRAINT_CHECK && parent_con->contype != CONSTRAINT_NOTNULL) continue; /* if the parent's constraint is marked NO INHERIT, it's not inherited */ if (parent_con->connoinherit) continue; if (parent_con->contype == CONSTRAINT_NOTNULL) parent_attno = extractNotNullColumn(parent_tuple); else parent_attno = InvalidAttrNumber; /* Search for a child constraint matching this one */ ScanKeyInit(&child_key, Anum_pg_constraint_conrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(child_rel))); child_scan = systable_beginscan(constraintrel, ConstraintRelidTypidNameIndexId, true, NULL, 1, &child_key); while (HeapTupleIsValid(child_tuple = systable_getnext(child_scan))) { Form_pg_constraint child_con = (Form_pg_constraint) GETSTRUCT(child_tuple); HeapTuple child_copy; if (child_con->contype != parent_con->contype) continue; /* * CHECK constraint are matched by constraint name, NOT NULL ones * by attribute number. */ if (child_con->contype == CONSTRAINT_CHECK) { if (strcmp(NameStr(parent_con->conname), NameStr(child_con->conname)) != 0) continue; } else if (child_con->contype == CONSTRAINT_NOTNULL) { Form_pg_attribute parent_attr; Form_pg_attribute child_attr; AttrNumber child_attno; parent_attr = TupleDescAttr(parent_rel->rd_att, parent_attno - 1); child_attno = extractNotNullColumn(child_tuple); if (parent_attno != attmap->attnums[child_attno - 1]) continue; child_attr = TupleDescAttr(child_rel->rd_att, child_attno - 1); /* there shouldn't be constraints on dropped columns */ if (parent_attr->attisdropped || child_attr->attisdropped) elog(ERROR, "found not-null constraint on dropped columns"); } if (child_con->contype == CONSTRAINT_CHECK && !constraints_equivalent(parent_tuple, child_tuple, RelationGetDescr(constraintrel))) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("child table \"%s\" has different definition for check constraint \"%s\"", RelationGetRelationName(child_rel), NameStr(parent_con->conname)))); /* * If the child constraint is "no inherit" then cannot merge */ if (child_con->connoinherit) ereport(ERROR, (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), errmsg("constraint \"%s\" conflicts with non-inherited constraint on child table \"%s\"", NameStr(child_con->conname), RelationGetRelationName(child_rel)))); /* * If the child constraint is "not valid" then cannot merge with a * valid parent constraint */ if (parent_con->convalidated && child_con->conenforced && !child_con->convalidated) ereport(ERROR, (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), errmsg("constraint \"%s\" conflicts with NOT VALID constraint on child table \"%s\"", NameStr(child_con->conname), RelationGetRelationName(child_rel)))); /* * A NOT ENFORCED child constraint cannot be merged with an * ENFORCED parent constraint. However, the reverse is allowed, * where the child constraint is ENFORCED. */ if (parent_con->conenforced && !child_con->conenforced) ereport(ERROR, (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), errmsg("constraint \"%s\" conflicts with NOT ENFORCED constraint on child table \"%s\"", NameStr(child_con->conname), RelationGetRelationName(child_rel)))); /* * OK, bump the child constraint's inheritance count. (If we fail * later on, this change will just roll back.) */ child_copy = heap_copytuple(child_tuple); child_con = (Form_pg_constraint) GETSTRUCT(child_copy); if (pg_add_s16_overflow(child_con->coninhcount, 1, &child_con->coninhcount)) ereport(ERROR, errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED), errmsg("too many inheritance parents")); /* * In case of partitions, an inherited constraint must be * inherited only once since it cannot have multiple parents and * it is never considered local. */ if (parent_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) { Assert(child_con->coninhcount == 1); child_con->conislocal = false; } CatalogTupleUpdate(constraintrel, &child_copy->t_self, child_copy); heap_freetuple(child_copy); found = true; break; } systable_endscan(child_scan); if (!found) { if (parent_con->contype == CONSTRAINT_NOTNULL) ereport(ERROR, errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("column \"%s\" in child table \"%s\" must be marked NOT NULL", get_attname(parent_relid, extractNotNullColumn(parent_tuple), false), RelationGetRelationName(child_rel))); ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("child table is missing constraint \"%s\"", NameStr(parent_con->conname)))); } } systable_endscan(parent_scan); table_close(constraintrel, RowExclusiveLock); } /* * ALTER TABLE NO INHERIT * * Return value is the address of the relation that is no longer parent. */ static ObjectAddress ATExecDropInherit(Relation rel, RangeVar *parent, LOCKMODE lockmode) { ObjectAddress address; Relation parent_rel; /* * AccessShareLock on the parent is probably enough, seeing that DROP * TABLE doesn't lock parent tables at all. We need some lock since we'll * be inspecting the parent's schema. */ parent_rel = table_openrv(parent, AccessShareLock); /* * We don't bother to check ownership of the parent table --- ownership of * the child is presumed enough rights. */ /* Off to RemoveInheritance() where most of the work happens */ RemoveInheritance(rel, parent_rel, false); ObjectAddressSet(address, RelationRelationId, RelationGetRelid(parent_rel)); /* keep our lock on the parent relation until commit */ table_close(parent_rel, NoLock); return address; } /* * MarkInheritDetached * * Set inhdetachpending for a partition, for ATExecDetachPartition * in concurrent mode. While at it, verify that no other partition is * already pending detach. */ static void MarkInheritDetached(Relation child_rel, Relation parent_rel) { Relation catalogRelation; SysScanDesc scan; ScanKeyData key; HeapTuple inheritsTuple; bool found = false; Assert(parent_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE); /* * Find pg_inherits entries by inhparent. (We need to scan them all in * order to verify that no other partition is pending detach.) */ catalogRelation = table_open(InheritsRelationId, RowExclusiveLock); ScanKeyInit(&key, Anum_pg_inherits_inhparent, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(parent_rel))); scan = systable_beginscan(catalogRelation, InheritsParentIndexId, true, NULL, 1, &key); while (HeapTupleIsValid(inheritsTuple = systable_getnext(scan))) { Form_pg_inherits inhForm; inhForm = (Form_pg_inherits) GETSTRUCT(inheritsTuple); if (inhForm->inhdetachpending) ereport(ERROR, errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("partition \"%s\" already pending detach in partitioned table \"%s.%s\"", get_rel_name(inhForm->inhrelid), get_namespace_name(parent_rel->rd_rel->relnamespace), RelationGetRelationName(parent_rel)), errhint("Use ALTER TABLE ... DETACH PARTITION ... FINALIZE to complete the pending detach operation.")); if (inhForm->inhrelid == RelationGetRelid(child_rel)) { HeapTuple newtup; newtup = heap_copytuple(inheritsTuple); ((Form_pg_inherits) GETSTRUCT(newtup))->inhdetachpending = true; CatalogTupleUpdate(catalogRelation, &inheritsTuple->t_self, newtup); found = true; heap_freetuple(newtup); /* keep looking, to ensure we catch others pending detach */ } } /* Done */ systable_endscan(scan); table_close(catalogRelation, RowExclusiveLock); if (!found) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_TABLE), errmsg("relation \"%s\" is not a partition of relation \"%s\"", RelationGetRelationName(child_rel), RelationGetRelationName(parent_rel)))); } /* * RemoveInheritance * * Drop a parent from the child's parents. This just adjusts the attinhcount * and attislocal of the columns and removes the pg_inherit and pg_depend * entries. expect_detached is passed down to DeleteInheritsTuple, q.v.. * * If attinhcount goes to 0 then attislocal gets set to true. If it goes back * up attislocal stays true, which means if a child is ever removed from a * parent then its columns will never be automatically dropped which may * surprise. But at least we'll never surprise by dropping columns someone * isn't expecting to be dropped which would actually mean data loss. * * coninhcount and conislocal for inherited constraints are adjusted in * exactly the same way. * * Common to ATExecDropInherit() and ATExecDetachPartition(). */ static void RemoveInheritance(Relation child_rel, Relation parent_rel, bool expect_detached) { Relation catalogRelation; SysScanDesc scan; ScanKeyData key[3]; HeapTuple attributeTuple, constraintTuple; AttrMap *attmap; List *connames; List *nncolumns; bool found; bool is_partitioning; is_partitioning = (parent_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE); found = DeleteInheritsTuple(RelationGetRelid(child_rel), RelationGetRelid(parent_rel), expect_detached, RelationGetRelationName(child_rel)); if (!found) { if (is_partitioning) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_TABLE), errmsg("relation \"%s\" is not a partition of relation \"%s\"", RelationGetRelationName(child_rel), RelationGetRelationName(parent_rel)))); else ereport(ERROR, (errcode(ERRCODE_UNDEFINED_TABLE), errmsg("relation \"%s\" is not a parent of relation \"%s\"", RelationGetRelationName(parent_rel), RelationGetRelationName(child_rel)))); } /* * Search through child columns looking for ones matching parent rel */ catalogRelation = table_open(AttributeRelationId, RowExclusiveLock); ScanKeyInit(&key[0], Anum_pg_attribute_attrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(child_rel))); scan = systable_beginscan(catalogRelation, AttributeRelidNumIndexId, true, NULL, 1, key); while (HeapTupleIsValid(attributeTuple = systable_getnext(scan))) { Form_pg_attribute att = (Form_pg_attribute) GETSTRUCT(attributeTuple); /* Ignore if dropped or not inherited */ if (att->attisdropped) continue; if (att->attinhcount <= 0) continue; if (SearchSysCacheExistsAttName(RelationGetRelid(parent_rel), NameStr(att->attname))) { /* Decrement inhcount and possibly set islocal to true */ HeapTuple copyTuple = heap_copytuple(attributeTuple); Form_pg_attribute copy_att = (Form_pg_attribute) GETSTRUCT(copyTuple); copy_att->attinhcount--; if (copy_att->attinhcount == 0) copy_att->attislocal = true; CatalogTupleUpdate(catalogRelation, ©Tuple->t_self, copyTuple); heap_freetuple(copyTuple); } } systable_endscan(scan); table_close(catalogRelation, RowExclusiveLock); /* * Likewise, find inherited check and not-null constraints and disinherit * them. To do this, we first need a list of the names of the parent's * check constraints. (We cheat a bit by only checking for name matches, * assuming that the expressions will match.) * * For NOT NULL columns, we store column numbers to match, mapping them in * to the child rel's attribute numbers. */ attmap = build_attrmap_by_name(RelationGetDescr(child_rel), RelationGetDescr(parent_rel), false); catalogRelation = table_open(ConstraintRelationId, RowExclusiveLock); ScanKeyInit(&key[0], Anum_pg_constraint_conrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(parent_rel))); scan = systable_beginscan(catalogRelation, ConstraintRelidTypidNameIndexId, true, NULL, 1, key); connames = NIL; nncolumns = NIL; while (HeapTupleIsValid(constraintTuple = systable_getnext(scan))) { Form_pg_constraint con = (Form_pg_constraint) GETSTRUCT(constraintTuple); if (con->connoinherit) continue; if (con->contype == CONSTRAINT_CHECK) connames = lappend(connames, pstrdup(NameStr(con->conname))); if (con->contype == CONSTRAINT_NOTNULL) { AttrNumber parent_attno = extractNotNullColumn(constraintTuple); nncolumns = lappend_int(nncolumns, attmap->attnums[parent_attno - 1]); } } systable_endscan(scan); /* Now scan the child's constraints to find matches */ ScanKeyInit(&key[0], Anum_pg_constraint_conrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(child_rel))); scan = systable_beginscan(catalogRelation, ConstraintRelidTypidNameIndexId, true, NULL, 1, key); while (HeapTupleIsValid(constraintTuple = systable_getnext(scan))) { Form_pg_constraint con = (Form_pg_constraint) GETSTRUCT(constraintTuple); bool match = false; /* * Match CHECK constraints by name, not-null constraints by column * number, and ignore all others. */ if (con->contype == CONSTRAINT_CHECK) { foreach_ptr(char, chkname, connames) { if (con->contype == CONSTRAINT_CHECK && strcmp(NameStr(con->conname), chkname) == 0) { match = true; connames = foreach_delete_current(connames, chkname); break; } } } else if (con->contype == CONSTRAINT_NOTNULL) { AttrNumber child_attno = extractNotNullColumn(constraintTuple); foreach_int(prevattno, nncolumns) { if (prevattno == child_attno) { match = true; nncolumns = foreach_delete_current(nncolumns, prevattno); break; } } } else continue; if (match) { /* Decrement inhcount and possibly set islocal to true */ HeapTuple copyTuple = heap_copytuple(constraintTuple); Form_pg_constraint copy_con = (Form_pg_constraint) GETSTRUCT(copyTuple); if (copy_con->coninhcount <= 0) /* shouldn't happen */ elog(ERROR, "relation %u has non-inherited constraint \"%s\"", RelationGetRelid(child_rel), NameStr(copy_con->conname)); copy_con->coninhcount--; if (copy_con->coninhcount == 0) copy_con->conislocal = true; CatalogTupleUpdate(catalogRelation, ©Tuple->t_self, copyTuple); heap_freetuple(copyTuple); } } /* We should have matched all constraints */ if (connames != NIL || nncolumns != NIL) elog(ERROR, "%d unmatched constraints while removing inheritance from \"%s\" to \"%s\"", list_length(connames) + list_length(nncolumns), RelationGetRelationName(child_rel), RelationGetRelationName(parent_rel)); systable_endscan(scan); table_close(catalogRelation, RowExclusiveLock); drop_parent_dependency(RelationGetRelid(child_rel), RelationRelationId, RelationGetRelid(parent_rel), child_dependency_type(is_partitioning)); /* * Post alter hook of this inherits. Since object_access_hook doesn't take * multiple object identifiers, we relay oid of parent relation using * auxiliary_id argument. */ InvokeObjectPostAlterHookArg(InheritsRelationId, RelationGetRelid(child_rel), 0, RelationGetRelid(parent_rel), false); } /* * Drop the dependency created by StoreCatalogInheritance1 (CREATE TABLE * INHERITS/ALTER TABLE INHERIT -- refclassid will be RelationRelationId) or * heap_create_with_catalog (CREATE TABLE OF/ALTER TABLE OF -- refclassid will * be TypeRelationId). There's no convenient way to do this, so go trawling * through pg_depend. */ static void drop_parent_dependency(Oid relid, Oid refclassid, Oid refobjid, DependencyType deptype) { Relation catalogRelation; SysScanDesc scan; ScanKeyData key[3]; HeapTuple depTuple; catalogRelation = table_open(DependRelationId, RowExclusiveLock); ScanKeyInit(&key[0], Anum_pg_depend_classid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationRelationId)); ScanKeyInit(&key[1], Anum_pg_depend_objid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(relid)); ScanKeyInit(&key[2], Anum_pg_depend_objsubid, BTEqualStrategyNumber, F_INT4EQ, Int32GetDatum(0)); scan = systable_beginscan(catalogRelation, DependDependerIndexId, true, NULL, 3, key); while (HeapTupleIsValid(depTuple = systable_getnext(scan))) { Form_pg_depend dep = (Form_pg_depend) GETSTRUCT(depTuple); if (dep->refclassid == refclassid && dep->refobjid == refobjid && dep->refobjsubid == 0 && dep->deptype == deptype) CatalogTupleDelete(catalogRelation, &depTuple->t_self); } systable_endscan(scan); table_close(catalogRelation, RowExclusiveLock); } /* * ALTER TABLE OF * * Attach a table to a composite type, as though it had been created with CREATE * TABLE OF. All attname, atttypid, atttypmod and attcollation must match. The * subject table must not have inheritance parents. These restrictions ensure * that you cannot create a configuration impossible with CREATE TABLE OF alone. * * The address of the type is returned. */ static ObjectAddress ATExecAddOf(Relation rel, const TypeName *ofTypename, LOCKMODE lockmode) { Oid relid = RelationGetRelid(rel); Type typetuple; Form_pg_type typeform; Oid typeid; Relation inheritsRelation, relationRelation; SysScanDesc scan; ScanKeyData key; AttrNumber table_attno, type_attno; TupleDesc typeTupleDesc, tableTupleDesc; ObjectAddress tableobj, typeobj; HeapTuple classtuple; AclResult aclresult; /* Validate the type. */ typetuple = typenameType(NULL, ofTypename, NULL); check_of_type(typetuple); typeform = (Form_pg_type) GETSTRUCT(typetuple); typeid = typeform->oid; aclresult = object_aclcheck(TypeRelationId, typeid, GetUserId(), ACL_USAGE); if (aclresult != ACLCHECK_OK) aclcheck_error_type(aclresult, typeid); /* Fail if the table has any inheritance parents. */ inheritsRelation = table_open(InheritsRelationId, AccessShareLock); ScanKeyInit(&key, Anum_pg_inherits_inhrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(relid)); scan = systable_beginscan(inheritsRelation, InheritsRelidSeqnoIndexId, true, NULL, 1, &key); if (HeapTupleIsValid(systable_getnext(scan))) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("typed tables cannot inherit"))); systable_endscan(scan); table_close(inheritsRelation, AccessShareLock); /* * Check the tuple descriptors for compatibility. Unlike inheritance, we * require that the order also match. However, attnotnull need not match. */ typeTupleDesc = lookup_rowtype_tupdesc(typeid, -1); tableTupleDesc = RelationGetDescr(rel); table_attno = 1; for (type_attno = 1; type_attno <= typeTupleDesc->natts; type_attno++) { Form_pg_attribute type_attr, table_attr; const char *type_attname, *table_attname; /* Get the next non-dropped type attribute. */ type_attr = TupleDescAttr(typeTupleDesc, type_attno - 1); if (type_attr->attisdropped) continue; type_attname = NameStr(type_attr->attname); /* Get the next non-dropped table attribute. */ do { if (table_attno > tableTupleDesc->natts) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("table is missing column \"%s\"", type_attname))); table_attr = TupleDescAttr(tableTupleDesc, table_attno - 1); table_attno++; } while (table_attr->attisdropped); table_attname = NameStr(table_attr->attname); /* Compare name. */ if (strncmp(table_attname, type_attname, NAMEDATALEN) != 0) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("table has column \"%s\" where type requires \"%s\"", table_attname, type_attname))); /* Compare type. */ if (table_attr->atttypid != type_attr->atttypid || table_attr->atttypmod != type_attr->atttypmod || table_attr->attcollation != type_attr->attcollation) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("table \"%s\" has different type for column \"%s\"", RelationGetRelationName(rel), type_attname))); } ReleaseTupleDesc(typeTupleDesc); /* Any remaining columns at the end of the table had better be dropped. */ for (; table_attno <= tableTupleDesc->natts; table_attno++) { Form_pg_attribute table_attr = TupleDescAttr(tableTupleDesc, table_attno - 1); if (!table_attr->attisdropped) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("table has extra column \"%s\"", NameStr(table_attr->attname)))); } /* If the table was already typed, drop the existing dependency. */ if (rel->rd_rel->reloftype) drop_parent_dependency(relid, TypeRelationId, rel->rd_rel->reloftype, DEPENDENCY_NORMAL); /* Record a dependency on the new type. */ tableobj.classId = RelationRelationId; tableobj.objectId = relid; tableobj.objectSubId = 0; typeobj.classId = TypeRelationId; typeobj.objectId = typeid; typeobj.objectSubId = 0; recordDependencyOn(&tableobj, &typeobj, DEPENDENCY_NORMAL); /* Update pg_class.reloftype */ relationRelation = table_open(RelationRelationId, RowExclusiveLock); classtuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relid)); if (!HeapTupleIsValid(classtuple)) elog(ERROR, "cache lookup failed for relation %u", relid); ((Form_pg_class) GETSTRUCT(classtuple))->reloftype = typeid; CatalogTupleUpdate(relationRelation, &classtuple->t_self, classtuple); InvokeObjectPostAlterHook(RelationRelationId, relid, 0); heap_freetuple(classtuple); table_close(relationRelation, RowExclusiveLock); ReleaseSysCache(typetuple); return typeobj; } /* * ALTER TABLE NOT OF * * Detach a typed table from its originating type. Just clear reloftype and * remove the dependency. */ static void ATExecDropOf(Relation rel, LOCKMODE lockmode) { Oid relid = RelationGetRelid(rel); Relation relationRelation; HeapTuple tuple; if (!OidIsValid(rel->rd_rel->reloftype)) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is not a typed table", RelationGetRelationName(rel)))); /* * We don't bother to check ownership of the type --- ownership of the * table is presumed enough rights. No lock required on the type, either. */ drop_parent_dependency(relid, TypeRelationId, rel->rd_rel->reloftype, DEPENDENCY_NORMAL); /* Clear pg_class.reloftype */ relationRelation = table_open(RelationRelationId, RowExclusiveLock); tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relid)); if (!HeapTupleIsValid(tuple)) elog(ERROR, "cache lookup failed for relation %u", relid); ((Form_pg_class) GETSTRUCT(tuple))->reloftype = InvalidOid; CatalogTupleUpdate(relationRelation, &tuple->t_self, tuple); InvokeObjectPostAlterHook(RelationRelationId, relid, 0); heap_freetuple(tuple); table_close(relationRelation, RowExclusiveLock); } /* * relation_mark_replica_identity: Update a table's replica identity * * Iff ri_type = REPLICA_IDENTITY_INDEX, indexOid must be the Oid of a suitable * index. Otherwise, it must be InvalidOid. * * Caller had better hold an exclusive lock on the relation, as the results * of running two of these concurrently wouldn't be pretty. */ static void relation_mark_replica_identity(Relation rel, char ri_type, Oid indexOid, bool is_internal) { Relation pg_index; Relation pg_class; HeapTuple pg_class_tuple; HeapTuple pg_index_tuple; Form_pg_class pg_class_form; Form_pg_index pg_index_form; ListCell *index; /* * Check whether relreplident has changed, and update it if so. */ pg_class = table_open(RelationRelationId, RowExclusiveLock); pg_class_tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(RelationGetRelid(rel))); if (!HeapTupleIsValid(pg_class_tuple)) elog(ERROR, "cache lookup failed for relation \"%s\"", RelationGetRelationName(rel)); pg_class_form = (Form_pg_class) GETSTRUCT(pg_class_tuple); if (pg_class_form->relreplident != ri_type) { pg_class_form->relreplident = ri_type; CatalogTupleUpdate(pg_class, &pg_class_tuple->t_self, pg_class_tuple); } table_close(pg_class, RowExclusiveLock); heap_freetuple(pg_class_tuple); /* * Update the per-index indisreplident flags correctly. */ pg_index = table_open(IndexRelationId, RowExclusiveLock); foreach(index, RelationGetIndexList(rel)) { Oid thisIndexOid = lfirst_oid(index); bool dirty = false; pg_index_tuple = SearchSysCacheCopy1(INDEXRELID, ObjectIdGetDatum(thisIndexOid)); if (!HeapTupleIsValid(pg_index_tuple)) elog(ERROR, "cache lookup failed for index %u", thisIndexOid); pg_index_form = (Form_pg_index) GETSTRUCT(pg_index_tuple); if (thisIndexOid == indexOid) { /* Set the bit if not already set. */ if (!pg_index_form->indisreplident) { dirty = true; pg_index_form->indisreplident = true; } } else { /* Unset the bit if set. */ if (pg_index_form->indisreplident) { dirty = true; pg_index_form->indisreplident = false; } } if (dirty) { CatalogTupleUpdate(pg_index, &pg_index_tuple->t_self, pg_index_tuple); InvokeObjectPostAlterHookArg(IndexRelationId, thisIndexOid, 0, InvalidOid, is_internal); /* * Invalidate the relcache for the table, so that after we commit * all sessions will refresh the table's replica identity index * before attempting any UPDATE or DELETE on the table. (If we * changed the table's pg_class row above, then a relcache inval * is already queued due to that; but we might not have.) */ CacheInvalidateRelcache(rel); } heap_freetuple(pg_index_tuple); } table_close(pg_index, RowExclusiveLock); } /* * ALTER TABLE <name> REPLICA IDENTITY ... */ static void ATExecReplicaIdentity(Relation rel, ReplicaIdentityStmt *stmt, LOCKMODE lockmode) { Oid indexOid; Relation indexRel; int key; if (stmt->identity_type == REPLICA_IDENTITY_DEFAULT) { relation_mark_replica_identity(rel, stmt->identity_type, InvalidOid, true); return; } else if (stmt->identity_type == REPLICA_IDENTITY_FULL) { relation_mark_replica_identity(rel, stmt->identity_type, InvalidOid, true); return; } else if (stmt->identity_type == REPLICA_IDENTITY_NOTHING) { relation_mark_replica_identity(rel, stmt->identity_type, InvalidOid, true); return; } else if (stmt->identity_type == REPLICA_IDENTITY_INDEX) { /* fallthrough */ ; } else elog(ERROR, "unexpected identity type %u", stmt->identity_type); /* Check that the index exists */ indexOid = get_relname_relid(stmt->name, rel->rd_rel->relnamespace); if (!OidIsValid(indexOid)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_OBJECT), errmsg("index \"%s\" for table \"%s\" does not exist", stmt->name, RelationGetRelationName(rel)))); indexRel = index_open(indexOid, ShareLock); /* Check that the index is on the relation we're altering. */ if (indexRel->rd_index == NULL || indexRel->rd_index->indrelid != RelationGetRelid(rel)) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is not an index for table \"%s\"", RelationGetRelationName(indexRel), RelationGetRelationName(rel)))); /* * The AM must support uniqueness, and the index must in fact be unique. * If we have a WITHOUT OVERLAPS constraint (identified by uniqueness + * exclusion), we can use that too. */ if ((!indexRel->rd_indam->amcanunique || !indexRel->rd_index->indisunique) && !(indexRel->rd_index->indisunique && indexRel->rd_index->indisexclusion)) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot use non-unique index \"%s\" as replica identity", RelationGetRelationName(indexRel)))); /* Deferred indexes are not guaranteed to be always unique. */ if (!indexRel->rd_index->indimmediate) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot use non-immediate index \"%s\" as replica identity", RelationGetRelationName(indexRel)))); /* Expression indexes aren't supported. */ if (RelationGetIndexExpressions(indexRel) != NIL) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot use expression index \"%s\" as replica identity", RelationGetRelationName(indexRel)))); /* Predicate indexes aren't supported. */ if (RelationGetIndexPredicate(indexRel) != NIL) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot use partial index \"%s\" as replica identity", RelationGetRelationName(indexRel)))); /* Check index for nullable columns. */ for (key = 0; key < IndexRelationGetNumberOfKeyAttributes(indexRel); key++) { int16 attno = indexRel->rd_index->indkey.values[key]; Form_pg_attribute attr; /* * Reject any other system columns. (Going forward, we'll disallow * indexes containing such columns in the first place, but they might * exist in older branches.) */ if (attno <= 0) ereport(ERROR, (errcode(ERRCODE_INVALID_COLUMN_REFERENCE), errmsg("index \"%s\" cannot be used as replica identity because column %d is a system column", RelationGetRelationName(indexRel), attno))); attr = TupleDescAttr(rel->rd_att, attno - 1); if (!attr->attnotnull) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("index \"%s\" cannot be used as replica identity because column \"%s\" is nullable", RelationGetRelationName(indexRel), NameStr(attr->attname)))); } /* This index is suitable for use as a replica identity. Mark it. */ relation_mark_replica_identity(rel, stmt->identity_type, indexOid, true); index_close(indexRel, NoLock); } /* * ALTER TABLE ENABLE/DISABLE ROW LEVEL SECURITY */ static void ATExecSetRowSecurity(Relation rel, bool rls) { Relation pg_class; Oid relid; HeapTuple tuple; relid = RelationGetRelid(rel); /* Pull the record for this relation and update it */ pg_class = table_open(RelationRelationId, RowExclusiveLock); tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relid)); if (!HeapTupleIsValid(tuple)) elog(ERROR, "cache lookup failed for relation %u", relid); ((Form_pg_class) GETSTRUCT(tuple))->relrowsecurity = rls; CatalogTupleUpdate(pg_class, &tuple->t_self, tuple); InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), 0); table_close(pg_class, RowExclusiveLock); heap_freetuple(tuple); } /* * ALTER TABLE FORCE/NO FORCE ROW LEVEL SECURITY */ static void ATExecForceNoForceRowSecurity(Relation rel, bool force_rls) { Relation pg_class; Oid relid; HeapTuple tuple; relid = RelationGetRelid(rel); pg_class = table_open(RelationRelationId, RowExclusiveLock); tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relid)); if (!HeapTupleIsValid(tuple)) elog(ERROR, "cache lookup failed for relation %u", relid); ((Form_pg_class) GETSTRUCT(tuple))->relforcerowsecurity = force_rls; CatalogTupleUpdate(pg_class, &tuple->t_self, tuple); InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), 0); table_close(pg_class, RowExclusiveLock); heap_freetuple(tuple); } /* * ALTER FOREIGN TABLE <name> OPTIONS (...) */ static void ATExecGenericOptions(Relation rel, List *options) { Relation ftrel; ForeignServer *server; ForeignDataWrapper *fdw; HeapTuple tuple; bool isnull; Datum repl_val[Natts_pg_foreign_table]; bool repl_null[Natts_pg_foreign_table]; bool repl_repl[Natts_pg_foreign_table]; Datum datum; Form_pg_foreign_table tableform; if (options == NIL) return; ftrel = table_open(ForeignTableRelationId, RowExclusiveLock); tuple = SearchSysCacheCopy1(FOREIGNTABLEREL, ObjectIdGetDatum(rel->rd_id)); if (!HeapTupleIsValid(tuple)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_OBJECT), errmsg("foreign table \"%s\" does not exist", RelationGetRelationName(rel)))); tableform = (Form_pg_foreign_table) GETSTRUCT(tuple); server = GetForeignServer(tableform->ftserver); fdw = GetForeignDataWrapper(server->fdwid); memset(repl_val, 0, sizeof(repl_val)); memset(repl_null, false, sizeof(repl_null)); memset(repl_repl, false, sizeof(repl_repl)); /* Extract the current options */ datum = SysCacheGetAttr(FOREIGNTABLEREL, tuple, Anum_pg_foreign_table_ftoptions, &isnull); if (isnull) datum = PointerGetDatum(NULL); /* Transform the options */ datum = transformGenericOptions(ForeignTableRelationId, datum, options, fdw->fdwvalidator); if (DatumGetPointer(datum) != NULL) repl_val[Anum_pg_foreign_table_ftoptions - 1] = datum; else repl_null[Anum_pg_foreign_table_ftoptions - 1] = true; repl_repl[Anum_pg_foreign_table_ftoptions - 1] = true; /* Everything looks good - update the tuple */ tuple = heap_modify_tuple(tuple, RelationGetDescr(ftrel), repl_val, repl_null, repl_repl); CatalogTupleUpdate(ftrel, &tuple->t_self, tuple); /* * Invalidate relcache so that all sessions will refresh any cached plans * that might depend on the old options. */ CacheInvalidateRelcache(rel); InvokeObjectPostAlterHook(ForeignTableRelationId, RelationGetRelid(rel), 0); table_close(ftrel, RowExclusiveLock); heap_freetuple(tuple); } /* * ALTER TABLE ALTER COLUMN SET COMPRESSION * * Return value is the address of the modified column */ static ObjectAddress ATExecSetCompression(Relation rel, const char *column, Node *newValue, LOCKMODE lockmode) { Relation attrel; HeapTuple tuple; Form_pg_attribute atttableform; AttrNumber attnum; char *compression; char cmethod; ObjectAddress address; compression = strVal(newValue); attrel = table_open(AttributeRelationId, RowExclusiveLock); /* copy the cache entry so we can scribble on it below */ tuple = SearchSysCacheCopyAttName(RelationGetRelid(rel), column); if (!HeapTupleIsValid(tuple)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" of relation \"%s\" does not exist", column, RelationGetRelationName(rel)))); /* prevent them from altering a system attribute */ atttableform = (Form_pg_attribute) GETSTRUCT(tuple); attnum = atttableform->attnum; if (attnum <= 0) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot alter system column \"%s\"", column))); /* * Check that column type is compressible, then get the attribute * compression method code */ cmethod = GetAttributeCompression(atttableform->atttypid, compression); /* update pg_attribute entry */ atttableform->attcompression = cmethod; CatalogTupleUpdate(attrel, &tuple->t_self, tuple); InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), attnum); /* * Apply the change to indexes as well (only for simple index columns, * matching behavior of index.c ConstructTupleDescriptor()). */ SetIndexStorageProperties(rel, attrel, attnum, false, 0, true, cmethod, lockmode); heap_freetuple(tuple); table_close(attrel, RowExclusiveLock); /* make changes visible */ CommandCounterIncrement(); ObjectAddressSubSet(address, RelationRelationId, RelationGetRelid(rel), attnum); return address; } /* * Preparation phase for SET LOGGED/UNLOGGED * * This verifies that we're not trying to change a temp table. Also, * existing foreign key constraints are checked to avoid ending up with * permanent tables referencing unlogged tables. */ static void ATPrepChangePersistence(AlteredTableInfo *tab, Relation rel, bool toLogged) { Relation pg_constraint; HeapTuple tuple; SysScanDesc scan; ScanKeyData skey[1]; /* * Disallow changing status for a temp table. Also verify whether we can * get away with doing nothing; in such cases we don't need to run the * checks below, either. */ switch (rel->rd_rel->relpersistence) { case RELPERSISTENCE_TEMP: ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("cannot change logged status of table \"%s\" because it is temporary", RelationGetRelationName(rel)), errtable(rel))); break; case RELPERSISTENCE_PERMANENT: if (toLogged) /* nothing to do */ return; break; case RELPERSISTENCE_UNLOGGED: if (!toLogged) /* nothing to do */ return; break; } /* * Check that the table is not part of any publication when changing to * UNLOGGED, as UNLOGGED tables can't be published. */ if (!toLogged && GetRelationIncludedPublications(RelationGetRelid(rel)) != NIL) ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("cannot change table \"%s\" to unlogged because it is part of a publication", RelationGetRelationName(rel)), errdetail("Unlogged relations cannot be replicated."))); /* * Check existing foreign key constraints to preserve the invariant that * permanent tables cannot reference unlogged ones. Self-referencing * foreign keys can safely be ignored. */ pg_constraint = table_open(ConstraintRelationId, AccessShareLock); /* * Scan conrelid if changing to permanent, else confrelid. This also * determines whether a useful index exists. */ ScanKeyInit(&skey[0], toLogged ? Anum_pg_constraint_conrelid : Anum_pg_constraint_confrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(rel))); scan = systable_beginscan(pg_constraint, toLogged ? ConstraintRelidTypidNameIndexId : InvalidOid, true, NULL, 1, skey); while (HeapTupleIsValid(tuple = systable_getnext(scan))) { Form_pg_constraint con = (Form_pg_constraint) GETSTRUCT(tuple); if (con->contype == CONSTRAINT_FOREIGN) { Oid foreignrelid; Relation foreignrel; /* the opposite end of what we used as scankey */ foreignrelid = toLogged ? con->confrelid : con->conrelid; /* ignore if self-referencing */ if (RelationGetRelid(rel) == foreignrelid) continue; foreignrel = relation_open(foreignrelid, AccessShareLock); if (toLogged) { if (!RelationIsPermanent(foreignrel)) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("could not change table \"%s\" to logged because it references unlogged table \"%s\"", RelationGetRelationName(rel), RelationGetRelationName(foreignrel)), errtableconstraint(rel, NameStr(con->conname)))); } else { if (RelationIsPermanent(foreignrel)) ereport(ERROR, (errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("could not change table \"%s\" to unlogged because it references logged table \"%s\"", RelationGetRelationName(rel), RelationGetRelationName(foreignrel)), errtableconstraint(rel, NameStr(con->conname)))); } relation_close(foreignrel, AccessShareLock); } } systable_endscan(scan); table_close(pg_constraint, AccessShareLock); /* force rewrite if necessary; see comment in ATRewriteTables */ tab->rewrite |= AT_REWRITE_ALTER_PERSISTENCE; if (toLogged) tab->newrelpersistence = RELPERSISTENCE_PERMANENT; else tab->newrelpersistence = RELPERSISTENCE_UNLOGGED; tab->chgPersistence = true; } /* * Execute ALTER TABLE SET SCHEMA */ ObjectAddress AlterTableNamespace(AlterObjectSchemaStmt *stmt, Oid *oldschema) { Relation rel; Oid relid; Oid oldNspOid; Oid nspOid; RangeVar *newrv; ObjectAddresses *objsMoved; ObjectAddress myself; relid = RangeVarGetRelidExtended(stmt->relation, AccessExclusiveLock, stmt->missing_ok ? RVR_MISSING_OK : 0, RangeVarCallbackForAlterRelation, stmt); if (!OidIsValid(relid)) { ereport(NOTICE, (errmsg("relation \"%s\" does not exist, skipping", stmt->relation->relname))); return InvalidObjectAddress; } rel = relation_open(relid, NoLock); oldNspOid = RelationGetNamespace(rel); /* If it's an owned sequence, disallow moving it by itself. */ if (rel->rd_rel->relkind == RELKIND_SEQUENCE) { Oid tableId; int32 colId; if (sequenceIsOwned(relid, DEPENDENCY_AUTO, &tableId, &colId) || sequenceIsOwned(relid, DEPENDENCY_INTERNAL, &tableId, &colId)) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot move an owned sequence into another schema"), errdetail("Sequence \"%s\" is linked to table \"%s\".", RelationGetRelationName(rel), get_rel_name(tableId)))); } /* Get and lock schema OID and check its permissions. */ newrv = makeRangeVar(stmt->newschema, RelationGetRelationName(rel), -1); nspOid = RangeVarGetAndCheckCreationNamespace(newrv, NoLock, NULL); /* common checks on switching namespaces */ CheckSetNamespace(oldNspOid, nspOid); objsMoved = new_object_addresses(); AlterTableNamespaceInternal(rel, oldNspOid, nspOid, objsMoved); free_object_addresses(objsMoved); ObjectAddressSet(myself, RelationRelationId, relid); if (oldschema) *oldschema = oldNspOid; /* close rel, but keep lock until commit */ relation_close(rel, NoLock); return myself; } /* * The guts of relocating a table or materialized view to another namespace: * besides moving the relation itself, its dependent objects are relocated to * the new schema. */ void AlterTableNamespaceInternal(Relation rel, Oid oldNspOid, Oid nspOid, ObjectAddresses *objsMoved) { Relation classRel; Assert(objsMoved != NULL); /* OK, modify the pg_class row and pg_depend entry */ classRel = table_open(RelationRelationId, RowExclusiveLock); AlterRelationNamespaceInternal(classRel, RelationGetRelid(rel), oldNspOid, nspOid, true, objsMoved); /* Fix the table's row type too, if it has one */ if (OidIsValid(rel->rd_rel->reltype)) AlterTypeNamespaceInternal(rel->rd_rel->reltype, nspOid, false, /* isImplicitArray */ false, /* ignoreDependent */ false, /* errorOnTableType */ objsMoved); /* Fix other dependent stuff */ AlterIndexNamespaces(classRel, rel, oldNspOid, nspOid, objsMoved); AlterSeqNamespaces(classRel, rel, oldNspOid, nspOid, objsMoved, AccessExclusiveLock); AlterConstraintNamespaces(RelationGetRelid(rel), oldNspOid, nspOid, false, objsMoved); table_close(classRel, RowExclusiveLock); } /* * The guts of relocating a relation to another namespace: fix the pg_class * entry, and the pg_depend entry if any. Caller must already have * opened and write-locked pg_class. */ void AlterRelationNamespaceInternal(Relation classRel, Oid relOid, Oid oldNspOid, Oid newNspOid, bool hasDependEntry, ObjectAddresses *objsMoved) { HeapTuple classTup; Form_pg_class classForm; ObjectAddress thisobj; bool already_done = false; /* no rel lock for relkind=c so use LOCKTAG_TUPLE */ classTup = SearchSysCacheLockedCopy1(RELOID, ObjectIdGetDatum(relOid)); if (!HeapTupleIsValid(classTup)) elog(ERROR, "cache lookup failed for relation %u", relOid); classForm = (Form_pg_class) GETSTRUCT(classTup); Assert(classForm->relnamespace == oldNspOid); thisobj.classId = RelationRelationId; thisobj.objectId = relOid; thisobj.objectSubId = 0; /* * If the object has already been moved, don't move it again. If it's * already in the right place, don't move it, but still fire the object * access hook. */ already_done = object_address_present(&thisobj, objsMoved); if (!already_done && oldNspOid != newNspOid) { ItemPointerData otid = classTup->t_self; /* check for duplicate name (more friendly than unique-index failure) */ if (get_relname_relid(NameStr(classForm->relname), newNspOid) != InvalidOid) ereport(ERROR, (errcode(ERRCODE_DUPLICATE_TABLE), errmsg("relation \"%s\" already exists in schema \"%s\"", NameStr(classForm->relname), get_namespace_name(newNspOid)))); /* classTup is a copy, so OK to scribble on */ classForm->relnamespace = newNspOid; CatalogTupleUpdate(classRel, &otid, classTup); UnlockTuple(classRel, &otid, InplaceUpdateTupleLock); /* Update dependency on schema if caller said so */ if (hasDependEntry && changeDependencyFor(RelationRelationId, relOid, NamespaceRelationId, oldNspOid, newNspOid) != 1) elog(ERROR, "could not change schema dependency for relation \"%s\"", NameStr(classForm->relname)); } else UnlockTuple(classRel, &classTup->t_self, InplaceUpdateTupleLock); if (!already_done) { add_exact_object_address(&thisobj, objsMoved); InvokeObjectPostAlterHook(RelationRelationId, relOid, 0); } heap_freetuple(classTup); } /* * Move all indexes for the specified relation to another namespace. * * Note: we assume adequate permission checking was done by the caller, * and that the caller has a suitable lock on the owning relation. */ static void AlterIndexNamespaces(Relation classRel, Relation rel, Oid oldNspOid, Oid newNspOid, ObjectAddresses *objsMoved) { List *indexList; ListCell *l; indexList = RelationGetIndexList(rel); foreach(l, indexList) { Oid indexOid = lfirst_oid(l); ObjectAddress thisobj; thisobj.classId = RelationRelationId; thisobj.objectId = indexOid; thisobj.objectSubId = 0; /* * Note: currently, the index will not have its own dependency on the * namespace, so we don't need to do changeDependencyFor(). There's no * row type in pg_type, either. * * XXX this objsMoved test may be pointless -- surely we have a single * dependency link from a relation to each index? */ if (!object_address_present(&thisobj, objsMoved)) { AlterRelationNamespaceInternal(classRel, indexOid, oldNspOid, newNspOid, false, objsMoved); add_exact_object_address(&thisobj, objsMoved); } } list_free(indexList); } /* * Move all identity and SERIAL-column sequences of the specified relation to another * namespace. * * Note: we assume adequate permission checking was done by the caller, * and that the caller has a suitable lock on the owning relation. */ static void AlterSeqNamespaces(Relation classRel, Relation rel, Oid oldNspOid, Oid newNspOid, ObjectAddresses *objsMoved, LOCKMODE lockmode) { Relation depRel; SysScanDesc scan; ScanKeyData key[2]; HeapTuple tup; /* * SERIAL sequences are those having an auto dependency on one of the * table's columns (we don't care *which* column, exactly). */ depRel = table_open(DependRelationId, AccessShareLock); ScanKeyInit(&key[0], Anum_pg_depend_refclassid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationRelationId)); ScanKeyInit(&key[1], Anum_pg_depend_refobjid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(rel))); /* we leave refobjsubid unspecified */ scan = systable_beginscan(depRel, DependReferenceIndexId, true, NULL, 2, key); while (HeapTupleIsValid(tup = systable_getnext(scan))) { Form_pg_depend depForm = (Form_pg_depend) GETSTRUCT(tup); Relation seqRel; /* skip dependencies other than auto dependencies on columns */ if (depForm->refobjsubid == 0 || depForm->classid != RelationRelationId || depForm->objsubid != 0 || !(depForm->deptype == DEPENDENCY_AUTO || depForm->deptype == DEPENDENCY_INTERNAL)) continue; /* Use relation_open just in case it's an index */ seqRel = relation_open(depForm->objid, lockmode); /* skip non-sequence relations */ if (RelationGetForm(seqRel)->relkind != RELKIND_SEQUENCE) { /* No need to keep the lock */ relation_close(seqRel, lockmode); continue; } /* Fix the pg_class and pg_depend entries */ AlterRelationNamespaceInternal(classRel, depForm->objid, oldNspOid, newNspOid, true, objsMoved); /* * Sequences used to have entries in pg_type, but no longer do. If we * ever re-instate that, we'll need to move the pg_type entry to the * new namespace, too (using AlterTypeNamespaceInternal). */ Assert(RelationGetForm(seqRel)->reltype == InvalidOid); /* Now we can close it. Keep the lock till end of transaction. */ relation_close(seqRel, NoLock); } systable_endscan(scan); relation_close(depRel, AccessShareLock); } /* * This code supports * CREATE TEMP TABLE ... ON COMMIT { DROP | PRESERVE ROWS | DELETE ROWS } * * Because we only support this for TEMP tables, it's sufficient to remember * the state in a backend-local data structure. */ /* * Register a newly-created relation's ON COMMIT action. */ void register_on_commit_action(Oid relid, OnCommitAction action) { OnCommitItem *oc; MemoryContext oldcxt; /* * We needn't bother registering the relation unless there is an ON COMMIT * action we need to take. */ if (action == ONCOMMIT_NOOP || action == ONCOMMIT_PRESERVE_ROWS) return; oldcxt = MemoryContextSwitchTo(CacheMemoryContext); oc = palloc_object(OnCommitItem); oc->relid = relid; oc->oncommit = action; oc->creating_subid = GetCurrentSubTransactionId(); oc->deleting_subid = InvalidSubTransactionId; /* * We use lcons() here so that ON COMMIT actions are processed in reverse * order of registration. That might not be essential but it seems * reasonable. */ on_commits = lcons(oc, on_commits); MemoryContextSwitchTo(oldcxt); } /* * Unregister any ON COMMIT action when a relation is deleted. * * Actually, we only mark the OnCommitItem entry as to be deleted after commit. */ void remove_on_commit_action(Oid relid) { ListCell *l; foreach(l, on_commits) { OnCommitItem *oc = (OnCommitItem *) lfirst(l); if (oc->relid == relid) { oc->deleting_subid = GetCurrentSubTransactionId(); break; } } } /* * Perform ON COMMIT actions. * * This is invoked just before actually committing, since it's possible * to encounter errors. */ void PreCommit_on_commit_actions(void) { ListCell *l; List *oids_to_truncate = NIL; List *oids_to_drop = NIL; foreach(l, on_commits) { OnCommitItem *oc = (OnCommitItem *) lfirst(l); /* Ignore entry if already dropped in this xact */ if (oc->deleting_subid != InvalidSubTransactionId) continue; switch (oc->oncommit) { case ONCOMMIT_NOOP: case ONCOMMIT_PRESERVE_ROWS: /* Do nothing (there shouldn't be such entries, actually) */ break; case ONCOMMIT_DELETE_ROWS: /* * If this transaction hasn't accessed any temporary * relations, we can skip truncating ON COMMIT DELETE ROWS * tables, as they must still be empty. */ if ((MyXactFlags & XACT_FLAGS_ACCESSEDTEMPNAMESPACE)) oids_to_truncate = lappend_oid(oids_to_truncate, oc->relid); break; case ONCOMMIT_DROP: oids_to_drop = lappend_oid(oids_to_drop, oc->relid); break; } } /* * Truncate relations before dropping so that all dependencies between * relations are removed after they are worked on. Doing it like this * might be a waste as it is possible that a relation being truncated will * be dropped anyway due to its parent being dropped, but this makes the * code more robust because of not having to re-check that the relation * exists at truncation time. */ if (oids_to_truncate != NIL) heap_truncate(oids_to_truncate); if (oids_to_drop != NIL) { ObjectAddresses *targetObjects = new_object_addresses(); foreach(l, oids_to_drop) { ObjectAddress object; object.classId = RelationRelationId; object.objectId = lfirst_oid(l); object.objectSubId = 0; Assert(!object_address_present(&object, targetObjects)); add_exact_object_address(&object, targetObjects); } /* * Object deletion might involve toast table access (to clean up * toasted catalog entries), so ensure we have a valid snapshot. */ PushActiveSnapshot(GetTransactionSnapshot()); /* * Since this is an automatic drop, rather than one directly initiated * by the user, we pass the PERFORM_DELETION_INTERNAL flag. */ performMultipleDeletions(targetObjects, DROP_CASCADE, PERFORM_DELETION_INTERNAL | PERFORM_DELETION_QUIETLY); PopActiveSnapshot(); #ifdef USE_ASSERT_CHECKING /* * Note that table deletion will call remove_on_commit_action, so the * entry should get marked as deleted. */ foreach(l, on_commits) { OnCommitItem *oc = (OnCommitItem *) lfirst(l); if (oc->oncommit != ONCOMMIT_DROP) continue; Assert(oc->deleting_subid != InvalidSubTransactionId); } #endif } } /* * Post-commit or post-abort cleanup for ON COMMIT management. * * All we do here is remove no-longer-needed OnCommitItem entries. * * During commit, remove entries that were deleted during this transaction; * during abort, remove those created during this transaction. */ void AtEOXact_on_commit_actions(bool isCommit) { ListCell *cur_item; foreach(cur_item, on_commits) { OnCommitItem *oc = (OnCommitItem *) lfirst(cur_item); if (isCommit ? oc->deleting_subid != InvalidSubTransactionId : oc->creating_subid != InvalidSubTransactionId) { /* cur_item must be removed */ on_commits = foreach_delete_current(on_commits, cur_item); pfree(oc); } else { /* cur_item must be preserved */ oc->creating_subid = InvalidSubTransactionId; oc->deleting_subid = InvalidSubTransactionId; } } } /* * Post-subcommit or post-subabort cleanup for ON COMMIT management. * * During subabort, we can immediately remove entries created during this * subtransaction. During subcommit, just relabel entries marked during * this subtransaction as being the parent's responsibility. */ void AtEOSubXact_on_commit_actions(bool isCommit, SubTransactionId mySubid, SubTransactionId parentSubid) { ListCell *cur_item; foreach(cur_item, on_commits) { OnCommitItem *oc = (OnCommitItem *) lfirst(cur_item); if (!isCommit && oc->creating_subid == mySubid) { /* cur_item must be removed */ on_commits = foreach_delete_current(on_commits, cur_item); pfree(oc); } else { /* cur_item must be preserved */ if (oc->creating_subid == mySubid) oc->creating_subid = parentSubid; if (oc->deleting_subid == mySubid) oc->deleting_subid = isCommit ? parentSubid : InvalidSubTransactionId; } } } /* * This is intended as a callback for RangeVarGetRelidExtended(). It allows * the relation to be locked only if (1) it's a plain or partitioned table, * materialized view, or TOAST table and (2) the current user is the owner (or * the superuser) or has been granted MAINTAIN. This meets the * permission-checking needs of CLUSTER, REINDEX TABLE, and REFRESH * MATERIALIZED VIEW; we expose it here so that it can be used by all. */ void RangeVarCallbackMaintainsTable(const RangeVar *relation, Oid relId, Oid oldRelId, void *arg) { char relkind; AclResult aclresult; /* Nothing to do if the relation was not found. */ if (!OidIsValid(relId)) return; /* * If the relation does exist, check whether it's an index. But note that * the relation might have been dropped between the time we did the name * lookup and now. In that case, there's nothing to do. */ relkind = get_rel_relkind(relId); if (!relkind) return; if (relkind != RELKIND_RELATION && relkind != RELKIND_TOASTVALUE && relkind != RELKIND_MATVIEW && relkind != RELKIND_PARTITIONED_TABLE) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is not a table or materialized view", relation->relname))); /* Check permissions */ aclresult = pg_class_aclcheck(relId, GetUserId(), ACL_MAINTAIN); if (aclresult != ACLCHECK_OK) aclcheck_error(aclresult, get_relkind_objtype(get_rel_relkind(relId)), relation->relname); } /* * Callback to RangeVarGetRelidExtended() for TRUNCATE processing. */ static void RangeVarCallbackForTruncate(const RangeVar *relation, Oid relId, Oid oldRelId, void *arg) { HeapTuple tuple; /* Nothing to do if the relation was not found. */ if (!OidIsValid(relId)) return; tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relId)); if (!HeapTupleIsValid(tuple)) /* should not happen */ elog(ERROR, "cache lookup failed for relation %u", relId); truncate_check_rel(relId, (Form_pg_class) GETSTRUCT(tuple)); truncate_check_perms(relId, (Form_pg_class) GETSTRUCT(tuple)); ReleaseSysCache(tuple); } /* * Callback for RangeVarGetRelidExtended(). Checks that the current user is * the owner of the relation, or superuser. */ void RangeVarCallbackOwnsRelation(const RangeVar *relation, Oid relId, Oid oldRelId, void *arg) { HeapTuple tuple; /* Nothing to do if the relation was not found. */ if (!OidIsValid(relId)) return; tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relId)); if (!HeapTupleIsValid(tuple)) /* should not happen */ elog(ERROR, "cache lookup failed for relation %u", relId); if (!object_ownercheck(RelationRelationId, relId, GetUserId())) aclcheck_error(ACLCHECK_NOT_OWNER, get_relkind_objtype(get_rel_relkind(relId)), relation->relname); /* * Conflict log tables are used internally for logical replication * conflict logging and should not be modified directly, as it could * disrupt conflict logging. */ if (IsConflictLogTableClass((Form_pg_class) GETSTRUCT(tuple))) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot change conflict log table \"%s\"", relation->relname), errdetail("Conflict log tables are system-managed tables for logical replication conflicts."))); if (!allowSystemTableMods && IsSystemClass(relId, (Form_pg_class) GETSTRUCT(tuple))) ereport(ERROR, (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), errmsg("permission denied: \"%s\" is a system catalog", relation->relname))); ReleaseSysCache(tuple); } /* * Common RangeVarGetRelid callback for rename, set schema, and alter table * processing. */ static void RangeVarCallbackForAlterRelation(const RangeVar *rv, Oid relid, Oid oldrelid, void *arg) { Node *stmt = (Node *) arg; ObjectType reltype; HeapTuple tuple; Form_pg_class classform; AclResult aclresult; char relkind; tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relid)); if (!HeapTupleIsValid(tuple)) return; /* concurrently dropped */ classform = (Form_pg_class) GETSTRUCT(tuple); relkind = classform->relkind; /* Must own relation. */ if (!object_ownercheck(RelationRelationId, relid, GetUserId())) aclcheck_error(ACLCHECK_NOT_OWNER, get_relkind_objtype(get_rel_relkind(relid)), rv->relname); /* * Conflict log tables are used internally for logical replication * conflict logging and should not be altered directly, as it could * disrupt conflict logging. */ if (IsConflictLogTableClass(classform)) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot alter conflict log table \"%s\"", rv->relname), errdetail("Conflict log tables are system-managed tables for logical replication conflicts."))); /* No system table modifications unless explicitly allowed. */ if (!allowSystemTableMods && IsSystemClass(relid, classform)) ereport(ERROR, (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), errmsg("permission denied: \"%s\" is a system catalog", rv->relname))); /* * Extract the specified relation type from the statement parse tree. * * Also, for ALTER .. RENAME, check permissions: the user must (still) * have CREATE rights on the containing namespace. */ if (IsA(stmt, RenameStmt)) { aclresult = object_aclcheck(NamespaceRelationId, classform->relnamespace, GetUserId(), ACL_CREATE); if (aclresult != ACLCHECK_OK) aclcheck_error(aclresult, OBJECT_SCHEMA, get_namespace_name(classform->relnamespace)); reltype = ((RenameStmt *) stmt)->renameType; } else if (IsA(stmt, AlterObjectSchemaStmt)) reltype = ((AlterObjectSchemaStmt *) stmt)->objectType; else if (IsA(stmt, AlterTableStmt)) reltype = ((AlterTableStmt *) stmt)->objtype; else { elog(ERROR, "unrecognized node type: %d", (int) nodeTag(stmt)); reltype = OBJECT_TABLE; /* placate compiler */ } /* * For compatibility with prior releases, we allow ALTER TABLE to be used * with most other types of relations (but not composite types). We allow * similar flexibility for ALTER INDEX in the case of RENAME, but not * otherwise. Otherwise, the user must select the correct form of the * command for the relation at issue. */ if (reltype == OBJECT_SEQUENCE && relkind != RELKIND_SEQUENCE) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is not a sequence", rv->relname))); if (reltype == OBJECT_VIEW && relkind != RELKIND_VIEW) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is not a view", rv->relname))); if (reltype == OBJECT_MATVIEW && relkind != RELKIND_MATVIEW) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is not a materialized view", rv->relname))); if (reltype == OBJECT_FOREIGN_TABLE && relkind != RELKIND_FOREIGN_TABLE) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is not a foreign table", rv->relname))); if (reltype == OBJECT_TYPE && relkind != RELKIND_COMPOSITE_TYPE) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is not a composite type", rv->relname))); if (reltype == OBJECT_PROPGRAPH && relkind != RELKIND_PROPGRAPH) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is not a property graph", rv->relname))); if (reltype == OBJECT_INDEX && relkind != RELKIND_INDEX && relkind != RELKIND_PARTITIONED_INDEX && !IsA(stmt, RenameStmt)) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is not an index", rv->relname))); /* * Don't allow ALTER TABLE on composite types. We want people to use ALTER * TYPE for that. */ if (reltype != OBJECT_TYPE && relkind == RELKIND_COMPOSITE_TYPE) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is a composite type", rv->relname), /* translator: %s is an SQL ALTER command */ errhint("Use %s instead.", "ALTER TYPE"))); /* * Don't allow ALTER TABLE .. SET SCHEMA on relations that can't be moved * to a different schema, such as indexes and TOAST tables. */ if (IsA(stmt, AlterObjectSchemaStmt)) { if (relkind == RELKIND_INDEX || relkind == RELKIND_PARTITIONED_INDEX) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot change schema of index \"%s\"", rv->relname), errhint("Change the schema of the table instead."))); else if (relkind == RELKIND_COMPOSITE_TYPE) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot change schema of composite type \"%s\"", rv->relname), /* translator: %s is an SQL ALTER command */ errhint("Use %s instead.", "ALTER TYPE"))); else if (relkind == RELKIND_TOASTVALUE) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot change schema of TOAST table \"%s\"", rv->relname), errhint("Change the schema of the table instead."))); } ReleaseSysCache(tuple); } /* * Transform any expressions present in the partition key * * Returns a transformed PartitionSpec. */ static PartitionSpec * transformPartitionSpec(Relation rel, PartitionSpec *partspec) { PartitionSpec *newspec; ParseState *pstate; ParseNamespaceItem *nsitem; ListCell *l; newspec = makeNode(PartitionSpec); newspec->strategy = partspec->strategy; newspec->partParams = NIL; newspec->location = partspec->location; /* Check valid number of columns for strategy */ if (partspec->strategy == PARTITION_STRATEGY_LIST && list_length(partspec->partParams) != 1) ereport(ERROR, (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), errmsg("cannot use \"list\" partition strategy with more than one column"))); /* * Create a dummy ParseState and insert the target relation as its sole * rangetable entry. We need a ParseState for transformExpr. */ pstate = make_parsestate(NULL); nsitem = addRangeTableEntryForRelation(pstate, rel, AccessShareLock, NULL, false, true); addNSItemToQuery(pstate, nsitem, true, true, true); /* take care of any partition expressions */ foreach(l, partspec->partParams) { PartitionElem *pelem = lfirst_node(PartitionElem, l); if (pelem->expr) { /* Copy, to avoid scribbling on the input */ pelem = copyObject(pelem); /* Now do parse transformation of the expression */ pelem->expr = transformExpr(pstate, pelem->expr, EXPR_KIND_PARTITION_EXPRESSION); /* we have to fix its collations too */ assign_expr_collations(pstate, pelem->expr); } newspec->partParams = lappend(newspec->partParams, pelem); } return newspec; } /* * Compute per-partition-column information from a list of PartitionElems. * Expressions in the PartitionElems must be parse-analyzed already. */ static void ComputePartitionAttrs(ParseState *pstate, Relation rel, List *partParams, AttrNumber *partattrs, List **partexprs, Oid *partopclass, Oid *partcollation, PartitionStrategy strategy) { int attn; ListCell *lc; Oid am_oid; attn = 0; foreach(lc, partParams) { PartitionElem *pelem = lfirst_node(PartitionElem, lc); Oid atttype; Oid attcollation; if (pelem->name != NULL) { /* Simple attribute reference */ HeapTuple atttuple; Form_pg_attribute attform; atttuple = SearchSysCacheAttName(RelationGetRelid(rel), pelem->name); if (!HeapTupleIsValid(atttuple)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_COLUMN), errmsg("column \"%s\" named in partition key does not exist", pelem->name), parser_errposition(pstate, pelem->location))); attform = (Form_pg_attribute) GETSTRUCT(atttuple); if (attform->attnum <= 0) ereport(ERROR, (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), errmsg("cannot use system column \"%s\" in partition key", pelem->name), parser_errposition(pstate, pelem->location))); /* * Stored generated columns cannot work: They are computed after * BEFORE triggers, but partition routing is done before all * triggers. Maybe virtual generated columns could be made to * work, but then they would need to be handled as an expression * below. */ if (attform->attgenerated) ereport(ERROR, (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), errmsg("cannot use generated column in partition key"), errdetail("Column \"%s\" is a generated column.", pelem->name), parser_errposition(pstate, pelem->location))); partattrs[attn] = attform->attnum; atttype = attform->atttypid; attcollation = attform->attcollation; ReleaseSysCache(atttuple); } else { /* Expression */ Node *expr = pelem->expr; char partattname[16]; Bitmapset *expr_attrs = NULL; int i; Assert(expr != NULL); atttype = exprType(expr); attcollation = exprCollation(expr); /* * The expression must be of a storable type (e.g., not RECORD). * The test is the same as for whether a table column is of a safe * type (which is why we needn't check for the non-expression * case). */ snprintf(partattname, sizeof(partattname), "%d", attn + 1); CheckAttributeType(partattname, atttype, attcollation, NIL, CHKATYPE_IS_PARTKEY); /* * Strip any top-level COLLATE clause. This ensures that we treat * "x COLLATE y" and "(x COLLATE y)" alike. */ while (IsA(expr, CollateExpr)) expr = (Node *) ((CollateExpr *) expr)->arg; /* * Examine all the columns in the partition key expression. When * the whole-row reference is present, examine all the columns of * the partitioned table. */ pull_varattnos(expr, 1, &expr_attrs); if (bms_is_member(0 - FirstLowInvalidHeapAttributeNumber, expr_attrs)) { expr_attrs = bms_add_range(expr_attrs, 1 - FirstLowInvalidHeapAttributeNumber, RelationGetNumberOfAttributes(rel) - FirstLowInvalidHeapAttributeNumber); expr_attrs = bms_del_member(expr_attrs, 0 - FirstLowInvalidHeapAttributeNumber); } i = -1; while ((i = bms_next_member(expr_attrs, i)) >= 0) { AttrNumber attno = i + FirstLowInvalidHeapAttributeNumber; Assert(attno != 0); /* * Cannot allow system column references, since that would * make partition routing impossible: their values won't be * known yet when we need to do that. */ if (attno < 0) ereport(ERROR, (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), errmsg("partition key expressions cannot contain system column references"))); /* * Stored generated columns cannot work: They are computed * after BEFORE triggers, but partition routing is done before * all triggers. Virtual generated columns could probably * work, but it would require more work elsewhere (for example * SET EXPRESSION would need to check whether the column is * used in partition keys). Seems safer to prohibit for now. */ if (TupleDescAttr(RelationGetDescr(rel), attno - 1)->attgenerated) ereport(ERROR, (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), errmsg("cannot use generated column in partition key"), errdetail("Column \"%s\" is a generated column.", get_attname(RelationGetRelid(rel), attno, false)), parser_errposition(pstate, pelem->location))); } if (IsA(expr, Var) && ((Var *) expr)->varattno > 0) { /* * User wrote "(column)" or "(column COLLATE something)". * Treat it like simple attribute anyway. */ partattrs[attn] = ((Var *) expr)->varattno; } else { partattrs[attn] = 0; /* marks the column as expression */ *partexprs = lappend(*partexprs, expr); /* * transformPartitionSpec() should have already rejected * subqueries, aggregates, window functions, and SRFs, based * on the EXPR_KIND_ for partition expressions. */ /* * Preprocess the expression before checking for mutability. * This is essential for the reasons described in * contain_mutable_functions_after_planning. However, we call * expression_planner for ourselves rather than using that * function, because if constant-folding reduces the * expression to a constant, we'd like to know that so we can * complain below. * * Like contain_mutable_functions_after_planning, assume that * expression_planner won't scribble on its input, so this * won't affect the partexprs entry we saved above. */ expr = (Node *) expression_planner((Expr *) expr); /* * Partition expressions cannot contain mutable functions, * because a given row must always map to the same partition * as long as there is no change in the partition boundary * structure. */ if (contain_mutable_functions(expr)) ereport(ERROR, (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), errmsg("functions in partition key expression must be marked IMMUTABLE"))); /* * While it is not exactly *wrong* for a partition expression * to be a constant, it seems better to reject such keys. */ if (IsA(expr, Const)) ereport(ERROR, (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), errmsg("cannot use constant expression as partition key"))); } } /* * Apply collation override if any */ if (pelem->collation) attcollation = get_collation_oid(pelem->collation, false); /* * Check we have a collation iff it's a collatable type. The only * expected failures here are (1) COLLATE applied to a noncollatable * type, or (2) partition expression had an unresolved collation. But * we might as well code this to be a complete consistency check. */ if (type_is_collatable(atttype)) { if (!OidIsValid(attcollation)) ereport(ERROR, (errcode(ERRCODE_INDETERMINATE_COLLATION), errmsg("could not determine which collation to use for partition expression"), errhint("Use the COLLATE clause to set the collation explicitly."))); } else { if (OidIsValid(attcollation)) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("collations are not supported by type %s", format_type_be(atttype)))); } partcollation[attn] = attcollation; /* * Identify the appropriate operator class. For list and range * partitioning, we use a btree operator class; hash partitioning uses * a hash operator class. */ if (strategy == PARTITION_STRATEGY_HASH) am_oid = HASH_AM_OID; else am_oid = BTREE_AM_OID; if (!pelem->opclass) { partopclass[attn] = GetDefaultOpClass(atttype, am_oid); if (!OidIsValid(partopclass[attn])) { if (strategy == PARTITION_STRATEGY_HASH) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_OBJECT), errmsg("data type %s has no default operator class for access method \"%s\"", format_type_be(atttype), "hash"), errhint("You must specify a hash operator class or define a default hash operator class for the data type."))); else ereport(ERROR, (errcode(ERRCODE_UNDEFINED_OBJECT), errmsg("data type %s has no default operator class for access method \"%s\"", format_type_be(atttype), "btree"), errhint("You must specify a btree operator class or define a default btree operator class for the data type."))); } } else partopclass[attn] = ResolveOpClass(pelem->opclass, atttype, am_oid == HASH_AM_OID ? "hash" : "btree", am_oid); attn++; } } /* * PartConstraintImpliedByRelConstraint * Do scanrel's existing constraints imply the partition constraint? * * "Existing constraints" include its check constraints and column-level * not-null constraints. partConstraint describes the partition constraint, * in implicit-AND form. */ bool PartConstraintImpliedByRelConstraint(Relation scanrel, List *partConstraint) { List *existConstraint = NIL; TupleConstr *constr = RelationGetDescr(scanrel)->constr; int i; if (constr && constr->has_not_null) { int natts = scanrel->rd_att->natts; for (i = 1; i <= natts; i++) { CompactAttribute *att = TupleDescCompactAttr(scanrel->rd_att, i - 1); /* invalid not-null constraint must be ignored here */ if (att->attnullability == ATTNULLABLE_VALID && !att->attisdropped) { Form_pg_attribute wholeatt = TupleDescAttr(scanrel->rd_att, i - 1); NullTest *ntest = makeNode(NullTest); ntest->arg = (Expr *) makeVar(1, i, wholeatt->atttypid, wholeatt->atttypmod, wholeatt->attcollation, 0); ntest->nulltesttype = IS_NOT_NULL; /* * argisrow=false is correct even for a composite column, * because attnotnull does not represent a SQL-spec IS NOT * NULL test in such a case, just IS DISTINCT FROM NULL. */ ntest->argisrow = false; ntest->location = -1; existConstraint = lappend(existConstraint, ntest); } } } return ConstraintImpliedByRelConstraint(scanrel, partConstraint, existConstraint); } /* * ConstraintImpliedByRelConstraint * Do scanrel's existing constraints imply the given constraint? * * testConstraint is the constraint to validate. provenConstraint is a * caller-provided list of conditions which this function may assume * to be true. Both provenConstraint and testConstraint must be in * implicit-AND form, must only contain immutable clauses, and must * contain only Vars with varno = 1. */ bool ConstraintImpliedByRelConstraint(Relation scanrel, List *testConstraint, List *provenConstraint) { List *existConstraint = list_copy(provenConstraint); TupleConstr *constr = RelationGetDescr(scanrel)->constr; int num_check, i; num_check = (constr != NULL) ? constr->num_check : 0; for (i = 0; i < num_check; i++) { Node *cexpr; /* * If this constraint hasn't been fully validated yet, we must ignore * it here. */ if (!constr->check[i].ccvalid) continue; /* * NOT ENFORCED constraints are always marked as invalid, which should * have been ignored. */ Assert(constr->check[i].ccenforced); cexpr = stringToNode(constr->check[i].ccbin); /* * Run each expression through const-simplification and * canonicalization. It is necessary, because we will be comparing it * to similarly-processed partition constraint expressions, and may * fail to detect valid matches without this. */ cexpr = eval_const_expressions(NULL, cexpr); cexpr = (Node *) canonicalize_qual((Expr *) cexpr, true); existConstraint = list_concat(existConstraint, make_ands_implicit((Expr *) cexpr)); } /* * Try to make the proof. Since we are comparing CHECK constraints, we * need to use weak implication, i.e., we assume existConstraint is * not-false and try to prove the same for testConstraint. * * Note that predicate_implied_by assumes its first argument is known * immutable. That should always be true for both NOT NULL and partition * constraints, so we don't test it here. */ return predicate_implied_by(testConstraint, existConstraint, true); } /* * QueuePartitionConstraintValidation * * Add an entry to wqueue to have the given partition constraint validated by * Phase 3, for the given relation, and all its children. * * We first verify whether the given constraint is implied by pre-existing * relation constraints; if it is, there's no need to scan the table to * validate, so don't queue in that case. */ static void QueuePartitionConstraintValidation(List **wqueue, Relation scanrel, List *partConstraint, bool validate_default) { /* * Based on the table's existing constraints, determine whether or not we * may skip scanning the table. */ if (PartConstraintImpliedByRelConstraint(scanrel, partConstraint)) { if (!validate_default) ereport(DEBUG1, (errmsg_internal("partition constraint for table \"%s\" is implied by existing constraints", RelationGetRelationName(scanrel)))); else ereport(DEBUG1, (errmsg_internal("updated partition constraint for default partition \"%s\" is implied by existing constraints", RelationGetRelationName(scanrel)))); return; } /* * Constraints proved insufficient. For plain relations, queue a * validation item now; for partitioned tables, recurse to process each * partition. */ if (scanrel->rd_rel->relkind == RELKIND_RELATION) { AlteredTableInfo *tab; /* Grab a work queue entry. */ tab = ATGetQueueEntry(wqueue, scanrel); Assert(tab->partition_constraint == NULL); tab->partition_constraint = (Expr *) linitial(partConstraint); tab->validate_default = validate_default; } else if (scanrel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) { PartitionDesc partdesc = RelationGetPartitionDesc(scanrel, true); int i; for (i = 0; i < partdesc->nparts; i++) { Relation part_rel; List *thisPartConstraint; /* * This is the minimum lock we need to prevent deadlocks. */ part_rel = table_open(partdesc->oids[i], AccessExclusiveLock); /* * Adjust the constraint for scanrel so that it matches this * partition's attribute numbers. */ thisPartConstraint = map_partition_varattnos(partConstraint, 1, part_rel, scanrel); QueuePartitionConstraintValidation(wqueue, part_rel, thisPartConstraint, validate_default); table_close(part_rel, NoLock); /* keep lock till commit */ } } } /* * attachPartitionTable: attach a new partition to the partitioned table * * wqueue: the ALTER TABLE work queue; can be NULL when not running as part * of an ALTER TABLE sequence. * rel: partitioned relation; * attachrel: relation of attached partition; * bound: bounds of attached relation. */ static void attachPartitionTable(List **wqueue, Relation rel, Relation attachrel, PartitionBoundSpec *bound) { /* * Create an inheritance; the relevant checks are performed inside the * function. */ CreateInheritance(attachrel, rel, true); /* Update the pg_class entry. */ StorePartitionBound(attachrel, rel, bound); /* Ensure there exists a correct set of indexes in the partition. */ AttachPartitionEnsureIndexes(wqueue, rel, attachrel); /* and triggers */ CloneRowTriggersToPartition(rel, attachrel); /* * Clone foreign key constraints. Callee is responsible for setting up * for phase 3 constraint verification. */ CloneForeignKeyConstraints(wqueue, rel, attachrel); } /* * ALTER TABLE <name> ATTACH PARTITION <partition-name> FOR VALUES * * Return the address of the newly attached partition. */ static ObjectAddress ATExecAttachPartition(List **wqueue, Relation rel, PartitionCmd *cmd, AlterTableUtilityContext *context) { Relation attachrel, catalog; List *attachrel_children; List *partConstraint; SysScanDesc scan; ScanKeyData skey; AttrNumber attno; int natts; TupleDesc tupleDesc; ObjectAddress address; const char *trigger_name; Oid defaultPartOid; List *partBoundConstraint; List *exceptpuboids = NIL; ParseState *pstate = make_parsestate(NULL); pstate->p_sourcetext = context->queryString; /* * We must lock the default partition if one exists, because attaching a * new partition will change its partition constraint. */ defaultPartOid = get_default_oid_from_partdesc(RelationGetPartitionDesc(rel, true)); if (OidIsValid(defaultPartOid)) LockRelationOid(defaultPartOid, AccessExclusiveLock); attachrel = table_openrv(cmd->name, AccessExclusiveLock); /* * XXX I think it'd be a good idea to grab locks on all tables referenced * by FKs at this point also. */ /* * Must be owner of both parent and source table -- parent was checked by * ATSimplePermissions call in ATPrepCmd */ ATSimplePermissions(AT_AttachPartition, attachrel, ATT_TABLE | ATT_PARTITIONED_TABLE | ATT_FOREIGN_TABLE); /* A partition can only have one parent */ if (attachrel->rd_rel->relispartition) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("\"%s\" is already a partition", RelationGetRelationName(attachrel)))); if (OidIsValid(attachrel->rd_rel->reloftype)) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot attach a typed table as partition"))); /* * Disallow attaching a partition if the table is referenced in a * publication EXCEPT clause. Changing the partition hierarchy could alter * the effective publication membership. */ exceptpuboids = GetRelationExcludedPublications(RelationGetRelid(attachrel)); if (exceptpuboids != NIL) { bool first = true; StringInfoData pubnames; initStringInfo(&pubnames); foreach_oid(pubid, exceptpuboids) { char *pubname = get_publication_name(pubid, false); if (first) appendStringInfo(&pubnames, _("\"%s\""), pubname); else appendStringInfo(&pubnames, _(", \"%s\""), pubname); first = false; } ereport(ERROR, errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg_plural("cannot attach table \"%s\" as partition because it is referenced in publication %s EXCEPT clause", "cannot attach table \"%s\" as partition because it is referenced in publications %s EXCEPT clause", list_length(exceptpuboids), RelationGetRelationName(attachrel), pubnames.data), errdetail("The publication EXCEPT clause cannot contain tables that are partitions."), errhint("Change the publication's EXCEPT clause using ALTER PUBLICATION ... SET ALL TABLES.")); } list_free(exceptpuboids); /* * Table being attached should not already be part of inheritance; either * as a child table... */ catalog = table_open(InheritsRelationId, AccessShareLock); ScanKeyInit(&skey, Anum_pg_inherits_inhrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(attachrel))); scan = systable_beginscan(catalog, InheritsRelidSeqnoIndexId, true, NULL, 1, &skey); if (HeapTupleIsValid(systable_getnext(scan))) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot attach inheritance child as partition"))); systable_endscan(scan); /* ...or as a parent table (except the case when it is partitioned) */ ScanKeyInit(&skey, Anum_pg_inherits_inhparent, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(attachrel))); scan = systable_beginscan(catalog, InheritsParentIndexId, true, NULL, 1, &skey); if (HeapTupleIsValid(systable_getnext(scan)) && attachrel->rd_rel->relkind == RELKIND_RELATION) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot attach inheritance parent as partition"))); systable_endscan(scan); table_close(catalog, AccessShareLock); /* * Prevent circularity by seeing if rel is a partition of attachrel. (In * particular, this disallows making a rel a partition of itself.) * * We do that by checking if rel is a member of the list of attachrel's * partitions provided the latter is partitioned at all. We want to avoid * having to construct this list again, so we request the strongest lock * on all partitions. We need the strongest lock, because we may decide * to scan them if we find out that the table being attached (or its leaf * partitions) may contain rows that violate the partition constraint. If * the table has a constraint that would prevent such rows, which by * definition is present in all the partitions, we need not scan the * table, nor its partitions. But we cannot risk a deadlock by taking a * weaker lock now and the stronger one only when needed. */ attachrel_children = find_all_inheritors(RelationGetRelid(attachrel), AccessExclusiveLock, NULL); if (list_member_oid(attachrel_children, RelationGetRelid(rel))) ereport(ERROR, (errcode(ERRCODE_DUPLICATE_TABLE), errmsg("circular inheritance not allowed"), errdetail("\"%s\" is already a child of \"%s\".", RelationGetRelationName(rel), RelationGetRelationName(attachrel)))); /* If the parent is permanent, so must be all of its partitions. */ if (rel->rd_rel->relpersistence != RELPERSISTENCE_TEMP && attachrel->rd_rel->relpersistence == RELPERSISTENCE_TEMP) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot attach a temporary relation as partition of permanent relation \"%s\"", RelationGetRelationName(rel)))); /* Temp parent cannot have a partition that is itself not a temp */ if (rel->rd_rel->relpersistence == RELPERSISTENCE_TEMP && attachrel->rd_rel->relpersistence != RELPERSISTENCE_TEMP) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot attach a permanent relation as partition of temporary relation \"%s\"", RelationGetRelationName(rel)))); /* If the parent is temp, it must belong to this session */ if (RELATION_IS_OTHER_TEMP(rel)) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot attach as partition of temporary relation of another session"))); /* Ditto for the partition */ if (RELATION_IS_OTHER_TEMP(attachrel)) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot attach temporary relation of another session as partition"))); /* * Check if attachrel has any identity columns or any columns that aren't * in the parent. */ tupleDesc = RelationGetDescr(attachrel); natts = tupleDesc->natts; for (attno = 1; attno <= natts; attno++) { Form_pg_attribute attribute = TupleDescAttr(tupleDesc, attno - 1); char *attributeName = NameStr(attribute->attname); /* Ignore dropped */ if (attribute->attisdropped) continue; if (attribute->attidentity) ereport(ERROR, errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("table \"%s\" being attached contains an identity column \"%s\"", RelationGetRelationName(attachrel), attributeName), errdetail("The new partition may not contain an identity column.")); /* Try to find the column in parent (matching on column name) */ if (!SearchSysCacheExists2(ATTNAME, ObjectIdGetDatum(RelationGetRelid(rel)), CStringGetDatum(attributeName))) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("table \"%s\" contains column \"%s\" not found in parent \"%s\"", RelationGetRelationName(attachrel), attributeName, RelationGetRelationName(rel)), errdetail("The new partition may contain only the columns present in parent."))); } /* * If child_rel has row-level triggers with transition tables, we * currently don't allow it to become a partition. See also prohibitions * in ATExecAddInherit() and CreateTrigger(). */ trigger_name = FindTriggerIncompatibleWithInheritance(attachrel->trigdesc); if (trigger_name != NULL) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("trigger \"%s\" prevents table \"%s\" from becoming a partition", trigger_name, RelationGetRelationName(attachrel)), errdetail("ROW triggers with transition tables are not supported on partitions."))); /* * Check that the new partition's bound is valid and does not overlap any * of existing partitions of the parent - note that it does not return on * error. */ check_new_partition_bound(RelationGetRelationName(attachrel), rel, cmd->bound, pstate); attachPartitionTable(wqueue, rel, attachrel, cmd->bound); /* * Generate a partition constraint from the partition bound specification. * If the parent itself is a partition, make sure to include its * constraint as well. */ partBoundConstraint = get_qual_from_partbound(rel, cmd->bound); /* * Use list_concat_copy() to avoid modifying partBoundConstraint in place, * since it's needed later to construct the constraint expression for * validating against the default partition, if any. */ partConstraint = list_concat_copy(partBoundConstraint, RelationGetPartitionQual(rel)); /* Skip validation if there are no constraints to validate. */ if (partConstraint) { /* * Run the partition quals through const-simplification similar to * check constraints. We skip canonicalize_qual, though, because * partition quals should be in canonical form already. */ partConstraint = (List *) eval_const_expressions(NULL, (Node *) partConstraint); /* XXX this sure looks wrong */ partConstraint = list_make1(make_ands_explicit(partConstraint)); /* * Adjust the generated constraint to match this partition's attribute * numbers. */ partConstraint = map_partition_varattnos(partConstraint, 1, attachrel, rel); /* Validate partition constraints against the table being attached. */ QueuePartitionConstraintValidation(wqueue, attachrel, partConstraint, false); } /* * If we're attaching a partition other than the default partition and a * default one exists, then that partition's partition constraint changes, * so add an entry to the work queue to validate it, too. (We must not do * this when the partition being attached is the default one; we already * did it above!) */ if (OidIsValid(defaultPartOid)) { Relation defaultrel; List *defPartConstraint; Assert(!cmd->bound->is_default); /* we already hold a lock on the default partition */ defaultrel = table_open(defaultPartOid, NoLock); defPartConstraint = get_proposed_default_constraint(partBoundConstraint); /* * Map the Vars in the constraint expression from rel's attnos to * defaultrel's. */ defPartConstraint = map_partition_varattnos(defPartConstraint, 1, defaultrel, rel); QueuePartitionConstraintValidation(wqueue, defaultrel, defPartConstraint, true); /* keep our lock until commit. */ table_close(defaultrel, NoLock); } ObjectAddressSet(address, RelationRelationId, RelationGetRelid(attachrel)); /* * If the partition we just attached is partitioned itself, invalidate * relcache for all descendent partitions too to ensure that their * rd_partcheck expression trees are rebuilt; partitions already locked at * the beginning of this function. */ if (attachrel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) { ListCell *l; foreach(l, attachrel_children) { CacheInvalidateRelcacheByRelid(lfirst_oid(l)); } } /* keep our lock until commit */ table_close(attachrel, NoLock); return address; } /* * AttachPartitionEnsureIndexes * subroutine for ATExecAttachPartition to create/match indexes * * Enforce the indexing rule for partitioned tables during ALTER TABLE / ATTACH * PARTITION: every partition must have an index attached to each index on the * partitioned table. */ static void AttachPartitionEnsureIndexes(List **wqueue, Relation rel, Relation attachrel) { List *idxes; List *attachRelIdxs; Relation *attachrelIdxRels; IndexInfo **attachInfos; ListCell *cell; MemoryContext cxt; MemoryContext oldcxt; cxt = AllocSetContextCreate(CurrentMemoryContext, "AttachPartitionEnsureIndexes", ALLOCSET_DEFAULT_SIZES); oldcxt = MemoryContextSwitchTo(cxt); idxes = RelationGetIndexList(rel); attachRelIdxs = RelationGetIndexList(attachrel); attachrelIdxRels = palloc_array(Relation, list_length(attachRelIdxs)); attachInfos = palloc_array(IndexInfo *, list_length(attachRelIdxs)); /* Build arrays of all existing indexes and their IndexInfos */ foreach_oid(cldIdxId, attachRelIdxs) { int i = foreach_current_index(cldIdxId); attachrelIdxRels[i] = index_open(cldIdxId, AccessShareLock); attachInfos[i] = BuildIndexInfo(attachrelIdxRels[i]); } /* * If we're attaching a foreign table, we must fail if any of the indexes * is a constraint index; otherwise, there's nothing to do here. Do this * before starting work, to avoid wasting the effort of building a few * non-unique indexes before coming across a unique one. */ if (attachrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) { foreach(cell, idxes) { Oid idx = lfirst_oid(cell); Relation idxRel = index_open(idx, AccessShareLock); if (idxRel->rd_index->indisunique || idxRel->rd_index->indisprimary) ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot attach foreign table \"%s\" as partition of partitioned table \"%s\"", RelationGetRelationName(attachrel), RelationGetRelationName(rel)), errdetail("Partitioned table \"%s\" contains unique indexes.", RelationGetRelationName(rel)))); index_close(idxRel, AccessShareLock); } goto out; } /* * For each index on the partitioned table, find a matching one in the * partition-to-be; if one is not found, create one. */ foreach(cell, idxes) { Oid idx = lfirst_oid(cell); Relation idxRel = index_open(idx, AccessShareLock); IndexInfo *info; AttrMap *attmap; bool found = false; Oid constraintOid; /* * Ignore indexes in the partitioned table other than partitioned * indexes. */ if (idxRel->rd_rel->relkind != RELKIND_PARTITIONED_INDEX) { index_close(idxRel, AccessShareLock); continue; } /* construct an indexinfo to compare existing indexes against */ info = BuildIndexInfo(idxRel); attmap = build_attrmap_by_name(RelationGetDescr(attachrel), RelationGetDescr(rel), false); constraintOid = get_relation_idx_constraint_oid(RelationGetRelid(rel), idx); /* * Scan the list of existing indexes in the partition-to-be, and mark * the first matching, valid, unattached one we find, if any, as * partition of the parent index. If we find one, we're done. */ for (int i = 0; i < list_length(attachRelIdxs); i++) { Oid cldIdxId = RelationGetRelid(attachrelIdxRels[i]); Oid cldConstrOid = InvalidOid; /* does this index have a parent? if so, can't use it */ if (attachrelIdxRels[i]->rd_rel->relispartition) continue; /* If this index is invalid, can't use it */ if (!attachrelIdxRels[i]->rd_index->indisvalid) continue; if (CompareIndexInfo(attachInfos[i], info, attachrelIdxRels[i]->rd_indcollation, idxRel->rd_indcollation, attachrelIdxRels[i]->rd_opfamily, idxRel->rd_opfamily, attmap)) { /* * If this index is being created in the parent because of a * constraint, then the child needs to have a constraint also, * so look for one. If there is no such constraint, this * index is no good, so keep looking. */ if (OidIsValid(constraintOid)) { cldConstrOid = get_relation_idx_constraint_oid(RelationGetRelid(attachrel), cldIdxId); /* no dice */ if (!OidIsValid(cldConstrOid)) continue; /* Ensure they're both the same type of constraint */ if (get_constraint_type(constraintOid) != get_constraint_type(cldConstrOid)) continue; } /* bingo. */ IndexSetParentIndex(attachrelIdxRels[i], idx); if (OidIsValid(constraintOid)) ConstraintSetParentConstraint(cldConstrOid, constraintOid, RelationGetRelid(attachrel)); found = true; CommandCounterIncrement(); break; } } /* * If no suitable index was found in the partition-to-be, create one * now. Note that if this is a PK, not-null constraints must already * exist. */ if (!found) { IndexStmt *stmt; Oid conOid; stmt = generateClonedIndexStmt(NULL, idxRel, attmap, &conOid); DefineIndex(NULL, RelationGetRelid(attachrel), stmt, InvalidOid, RelationGetRelid(idxRel), conOid, -1, true, false, false, false, false); } index_close(idxRel, AccessShareLock); } out: /* Clean up. */ for (int i = 0; i < list_length(attachRelIdxs); i++) index_close(attachrelIdxRels[i], AccessShareLock); MemoryContextSwitchTo(oldcxt); MemoryContextDelete(cxt); } /* * CloneRowTriggersToPartition * subroutine for ATExecAttachPartition/DefineRelation to create row * triggers on partitions */ static void CloneRowTriggersToPartition(Relation parent, Relation partition) { Relation pg_trigger; ScanKeyData key; SysScanDesc scan; HeapTuple tuple; MemoryContext perTupCxt; ScanKeyInit(&key, Anum_pg_trigger_tgrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(parent))); pg_trigger = table_open(TriggerRelationId, RowExclusiveLock); scan = systable_beginscan(pg_trigger, TriggerRelidNameIndexId, true, NULL, 1, &key); perTupCxt = AllocSetContextCreate(CurrentMemoryContext, "clone trig", ALLOCSET_SMALL_SIZES); while (HeapTupleIsValid(tuple = systable_getnext(scan))) { Form_pg_trigger trigForm = (Form_pg_trigger) GETSTRUCT(tuple); CreateTrigStmt *trigStmt; Node *qual = NULL; Datum value; bool isnull; List *cols = NIL; List *trigargs = NIL; MemoryContext oldcxt; /* * Ignore statement-level triggers; those are not cloned. */ if (!TRIGGER_FOR_ROW(trigForm->tgtype)) continue; /* * Don't clone internal triggers, because the constraint cloning code * will. */ if (trigForm->tgisinternal) continue; /* * Complain if we find an unexpected trigger type. */ if (!TRIGGER_FOR_BEFORE(trigForm->tgtype) && !TRIGGER_FOR_AFTER(trigForm->tgtype)) elog(ERROR, "unexpected trigger \"%s\" found", NameStr(trigForm->tgname)); /* Use short-lived context for CREATE TRIGGER */ oldcxt = MemoryContextSwitchTo(perTupCxt); /* * If there is a WHEN clause, generate a 'cooked' version of it that's * appropriate for the partition. */ value = heap_getattr(tuple, Anum_pg_trigger_tgqual, RelationGetDescr(pg_trigger), &isnull); if (!isnull) { qual = stringToNode(TextDatumGetCString(value)); qual = (Node *) map_partition_varattnos((List *) qual, PRS2_OLD_VARNO, partition, parent); qual = (Node *) map_partition_varattnos((List *) qual, PRS2_NEW_VARNO, partition, parent); } /* * If there is a column list, transform it to a list of column names. * Note we don't need to map this list in any way ... */ if (trigForm->tgattr.dim1 > 0) { int i; for (i = 0; i < trigForm->tgattr.dim1; i++) { Form_pg_attribute col; col = TupleDescAttr(parent->rd_att, trigForm->tgattr.values[i] - 1); cols = lappend(cols, makeString(pstrdup(NameStr(col->attname)))); } } /* Reconstruct trigger arguments list. */ if (trigForm->tgnargs > 0) { char *p; value = heap_getattr(tuple, Anum_pg_trigger_tgargs, RelationGetDescr(pg_trigger), &isnull); if (isnull) elog(ERROR, "tgargs is null for trigger \"%s\" in partition \"%s\"", NameStr(trigForm->tgname), RelationGetRelationName(partition)); p = (char *) VARDATA_ANY(DatumGetByteaPP(value)); for (int i = 0; i < trigForm->tgnargs; i++) { trigargs = lappend(trigargs, makeString(pstrdup(p))); p += strlen(p) + 1; } } trigStmt = makeNode(CreateTrigStmt); trigStmt->replace = false; trigStmt->isconstraint = OidIsValid(trigForm->tgconstraint); trigStmt->trigname = NameStr(trigForm->tgname); trigStmt->relation = NULL; trigStmt->funcname = NULL; /* passed separately */ trigStmt->args = trigargs; trigStmt->row = true; trigStmt->timing = trigForm->tgtype & TRIGGER_TYPE_TIMING_MASK; trigStmt->events = trigForm->tgtype & TRIGGER_TYPE_EVENT_MASK; trigStmt->columns = cols; trigStmt->whenClause = NULL; /* passed separately */ trigStmt->transitionRels = NIL; /* not supported at present */ trigStmt->deferrable = trigForm->tgdeferrable; trigStmt->initdeferred = trigForm->tginitdeferred; trigStmt->constrrel = NULL; /* passed separately */ CreateTriggerFiringOn(trigStmt, NULL, RelationGetRelid(partition), trigForm->tgconstrrelid, InvalidOid, InvalidOid, trigForm->tgfoid, trigForm->oid, qual, false, true, trigForm->tgenabled); MemoryContextSwitchTo(oldcxt); MemoryContextReset(perTupCxt); } MemoryContextDelete(perTupCxt); systable_endscan(scan); table_close(pg_trigger, RowExclusiveLock); } /* * ALTER TABLE DETACH PARTITION * * Return the address of the relation that is no longer a partition of rel. * * If concurrent mode is requested, we run in two transactions. A side- * effect is that this command cannot run in a multi-part ALTER TABLE. * Currently, that's enforced by the grammar. * * The strategy for concurrency is to first modify the partition's * pg_inherit catalog row to make it visible to everyone that the * partition is detached, lock the partition against writes, and commit * the transaction; anyone who requests the partition descriptor from * that point onwards has to ignore such a partition. In a second * transaction, we wait until all transactions that could have seen the * partition as attached are gone, then we remove the rest of partition * metadata (pg_inherits and pg_class.relpartbounds). */ static ObjectAddress ATExecDetachPartition(List **wqueue, AlteredTableInfo *tab, Relation rel, RangeVar *name, bool concurrent) { Relation partRel; ObjectAddress address; Oid defaultPartOid; /* * We must lock the default partition, because detaching this partition * will change its partition constraint. */ defaultPartOid = get_default_oid_from_partdesc(RelationGetPartitionDesc(rel, true)); if (OidIsValid(defaultPartOid)) { /* * Concurrent detaching when a default partition exists is not * supported. The main problem is that the default partition * constraint would change. And there's a definitional problem: what * should happen to the tuples that are being inserted that belong to * the partition being detached? Putting them on the partition being * detached would be wrong, since they'd become "lost" after the * detaching completes but we cannot put them in the default partition * either until we alter its partition constraint. * * I think we could solve this problem if we effected the constraint * change before committing the first transaction. But the lock would * have to remain AEL and it would cause concurrent query planning to * be blocked, so changing it that way would be even worse. */ if (concurrent) ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("cannot detach partitions concurrently when a default partition exists"))); LockRelationOid(defaultPartOid, AccessExclusiveLock); } /* * In concurrent mode, the partition is locked with share-update-exclusive * in the first transaction. This allows concurrent transactions to be * doing DML to the partition. */ partRel = table_openrv(name, concurrent ? ShareUpdateExclusiveLock : AccessExclusiveLock); /* * Check inheritance conditions and either delete the pg_inherits row (in * non-concurrent mode) or just set the inhdetachpending flag. */ if (!concurrent) RemoveInheritance(partRel, rel, false); else MarkInheritDetached(partRel, rel); /* * Ensure that foreign keys still hold after this detach. This keeps * locks on the referencing tables, which prevents concurrent transactions * from adding rows that we wouldn't see. For this to work in concurrent * mode, it is critical that the partition appears as no longer attached * for the RI queries as soon as the first transaction commits. */ ATDetachCheckNoForeignKeyRefs(partRel); /* * Concurrent mode has to work harder; first we add a new constraint to * the partition that matches the partition constraint. Then we close our * existing transaction, and in a new one wait for all processes to catch * up on the catalog updates we've done so far; at that point we can * complete the operation. */ if (concurrent) { Oid partrelid, parentrelid; LOCKTAG tag; char *parentrelname; char *partrelname; /* * We're almost done now; the only traces that remain are the * pg_inherits tuple and the partition's relpartbounds. Before we can * remove those, we need to wait until all transactions that know that * this is a partition are gone. */ /* * Remember relation OIDs to re-acquire them later; and relation names * too, for error messages if something is dropped in between. */ partrelid = RelationGetRelid(partRel); parentrelid = RelationGetRelid(rel); parentrelname = MemoryContextStrdup(PortalContext, RelationGetRelationName(rel)); partrelname = MemoryContextStrdup(PortalContext, RelationGetRelationName(partRel)); /* Invalidate relcache entries for the parent -- must be before close */ CacheInvalidateRelcache(rel); table_close(partRel, NoLock); table_close(rel, NoLock); tab->rel = NULL; /* Make updated catalog entry visible */ PopActiveSnapshot(); CommitTransactionCommand(); StartTransactionCommand(); /* * Now wait. This ensures that all queries that were planned * including the partition are finished before we remove the rest of * catalog entries. We don't need or indeed want to acquire this * lock, though -- that would block later queries. * * We don't need to concern ourselves with waiting for a lock on the * partition itself, since we will acquire AccessExclusiveLock below. */ SET_LOCKTAG_RELATION(tag, MyDatabaseId, parentrelid); WaitForLockersMultiple(list_make1(&tag), AccessExclusiveLock, false); /* * Now acquire locks in both relations again. Note they may have been * removed in the meantime, so care is required. */ rel = try_relation_open(parentrelid, ShareUpdateExclusiveLock); partRel = try_relation_open(partrelid, AccessExclusiveLock); /* If the relations aren't there, something bad happened; bail out */ if (rel == NULL) { if (partRel != NULL) /* shouldn't happen */ elog(WARNING, "dangling partition \"%s\" remains, can't fix", partrelname); ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("partitioned table \"%s\" was removed concurrently", parentrelname))); } if (partRel == NULL) ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("partition \"%s\" was removed concurrently", partrelname))); tab->rel = rel; } /* * Detaching the partition might involve TOAST table access, so ensure we * have a valid snapshot. */ PushActiveSnapshot(GetTransactionSnapshot()); /* Do the final part of detaching */ DetachPartitionFinalize(rel, partRel, concurrent, defaultPartOid); PopActiveSnapshot(); ObjectAddressSet(address, RelationRelationId, RelationGetRelid(partRel)); /* keep our lock until commit */ table_close(partRel, NoLock); return address; } /* * Second part of ALTER TABLE .. DETACH. * * This is separate so that it can be run independently when the second * transaction of the concurrent algorithm fails (crash or abort). */ static void DetachPartitionFinalize(Relation rel, Relation partRel, bool concurrent, Oid defaultPartOid) { Relation classRel; List *fks; ListCell *cell; List *indexes; Datum new_val[Natts_pg_class]; bool new_null[Natts_pg_class], new_repl[Natts_pg_class]; HeapTuple tuple, newtuple; Relation trigrel = NULL; List *fkoids = NIL; if (concurrent) { /* * We can remove the pg_inherits row now. (In the non-concurrent case, * this was already done). */ RemoveInheritance(partRel, rel, true); } /* Drop any triggers that were cloned on creation/attach. */ DropClonedTriggersFromPartition(RelationGetRelid(partRel)); /* * Detach any foreign keys that are inherited. This includes creating * additional action triggers. */ fks = copyObject(RelationGetFKeyList(partRel)); if (fks != NIL) trigrel = table_open(TriggerRelationId, RowExclusiveLock); /* * It's possible that the partition being detached has a foreign key that * references a partitioned table. When that happens, there are multiple * pg_constraint rows for the partition: one points to the partitioned * table itself, while the others point to each of its partitions. Only * the topmost one is to be considered here; the child constraints must be * left alone, because conceptually those aren't coming from our parent * partitioned table, but from this partition itself. * * We implement this by collecting all the constraint OIDs in a first scan * of the FK array, and skipping in the loop below those constraints whose * parents are listed here. */ foreach_node(ForeignKeyCacheInfo, fk, fks) fkoids = lappend_oid(fkoids, fk->conoid); foreach(cell, fks) { ForeignKeyCacheInfo *fk = lfirst(cell); HeapTuple contup; Form_pg_constraint conform; contup = SearchSysCache1(CONSTROID, ObjectIdGetDatum(fk->conoid)); if (!HeapTupleIsValid(contup)) elog(ERROR, "cache lookup failed for constraint %u", fk->conoid); conform = (Form_pg_constraint) GETSTRUCT(contup); /* * Consider only inherited foreign keys, and only if their parents * aren't in the list. */ if (conform->contype != CONSTRAINT_FOREIGN || !OidIsValid(conform->conparentid) || list_member_oid(fkoids, conform->conparentid)) { ReleaseSysCache(contup); continue; } /* * The constraint on this table must be marked no longer a child of * the parent's constraint, as do its check triggers. */ ConstraintSetParentConstraint(fk->conoid, InvalidOid, InvalidOid); /* * Also, look up the partition's "check" triggers corresponding to the * ENFORCED constraint being detached and detach them from the parent * triggers. NOT ENFORCED constraints do not have these triggers; * therefore, this step is not needed. */ if (fk->conenforced) { Oid insertTriggerOid, updateTriggerOid; GetForeignKeyCheckTriggers(trigrel, fk->conoid, fk->confrelid, fk->conrelid, &insertTriggerOid, &updateTriggerOid); Assert(OidIsValid(insertTriggerOid)); TriggerSetParentTrigger(trigrel, insertTriggerOid, InvalidOid, RelationGetRelid(partRel)); Assert(OidIsValid(updateTriggerOid)); TriggerSetParentTrigger(trigrel, updateTriggerOid, InvalidOid, RelationGetRelid(partRel)); } /* * Lastly, create the action triggers on the referenced table, using * addFkRecurseReferenced, which requires some elaborate setup (so put * it in a separate block). While at it, if the table is partitioned, * that function will recurse to create the pg_constraint rows and * action triggers for each partition. * * Note there's no need to do addFkConstraint() here, because the * pg_constraint row already exists. */ { Constraint *fkconstraint; int numfks; AttrNumber conkey[INDEX_MAX_KEYS]; AttrNumber confkey[INDEX_MAX_KEYS]; Oid conpfeqop[INDEX_MAX_KEYS]; Oid conppeqop[INDEX_MAX_KEYS]; Oid conffeqop[INDEX_MAX_KEYS]; int numfkdelsetcols; AttrNumber confdelsetcols[INDEX_MAX_KEYS]; Relation refdRel; DeconstructFkConstraintRow(contup, &numfks, conkey, confkey, conpfeqop, conppeqop, conffeqop, &numfkdelsetcols, confdelsetcols); /* Create a synthetic node we'll use throughout */ fkconstraint = makeNode(Constraint); fkconstraint->contype = CONSTRAINT_FOREIGN; fkconstraint->conname = pstrdup(NameStr(conform->conname)); fkconstraint->deferrable = conform->condeferrable; fkconstraint->initdeferred = conform->condeferred; fkconstraint->is_enforced = conform->conenforced; fkconstraint->skip_validation = true; fkconstraint->initially_valid = conform->convalidated; /* a few irrelevant fields omitted here */ fkconstraint->pktable = NULL; fkconstraint->fk_attrs = NIL; fkconstraint->pk_attrs = NIL; fkconstraint->fk_matchtype = conform->confmatchtype; fkconstraint->fk_upd_action = conform->confupdtype; fkconstraint->fk_del_action = conform->confdeltype; fkconstraint->fk_del_set_cols = NIL; fkconstraint->old_conpfeqop = NIL; fkconstraint->old_pktable_oid = InvalidOid; fkconstraint->location = -1; /* set up colnames, used to generate the constraint name */ for (int i = 0; i < numfks; i++) { Form_pg_attribute att; att = TupleDescAttr(RelationGetDescr(partRel), conkey[i] - 1); fkconstraint->fk_attrs = lappend(fkconstraint->fk_attrs, makeString(NameStr(att->attname))); } refdRel = table_open(fk->confrelid, ShareRowExclusiveLock); addFkRecurseReferenced(fkconstraint, partRel, refdRel, conform->conindid, fk->conoid, numfks, confkey, conkey, conpfeqop, conppeqop, conffeqop, numfkdelsetcols, confdelsetcols, true, InvalidOid, InvalidOid, conform->conperiod); table_close(refdRel, NoLock); /* keep lock till end of xact */ } ReleaseSysCache(contup); } list_free_deep(fks); if (trigrel) table_close(trigrel, RowExclusiveLock); /* * Any sub-constraints that are in the referenced-side of a larger * constraint have to be removed. This partition is no longer part of the * key space of the constraint. */ foreach(cell, GetParentedForeignKeyRefs(partRel)) { Oid constrOid = lfirst_oid(cell); ObjectAddress constraint; ConstraintSetParentConstraint(constrOid, InvalidOid, InvalidOid); deleteDependencyRecordsForClass(ConstraintRelationId, constrOid, ConstraintRelationId, DEPENDENCY_INTERNAL); CommandCounterIncrement(); ObjectAddressSet(constraint, ConstraintRelationId, constrOid); performDeletion(&constraint, DROP_RESTRICT, 0); } /* Now we can detach indexes */ indexes = RelationGetIndexList(partRel); foreach(cell, indexes) { Oid idxid = lfirst_oid(cell); Oid parentidx; Relation idx; Oid constrOid; Oid parentConstrOid; if (!has_superclass(idxid)) continue; parentidx = get_partition_parent(idxid, false); Assert((IndexGetRelation(parentidx, false) == RelationGetRelid(rel))); idx = index_open(idxid, AccessExclusiveLock); IndexSetParentIndex(idx, InvalidOid); /* * If there's a constraint associated with the index, detach it too. * Careful: it is possible for a constraint index in a partition to be * the child of a non-constraint index, so verify whether the parent * index does actually have a constraint. */ constrOid = get_relation_idx_constraint_oid(RelationGetRelid(partRel), idxid); parentConstrOid = get_relation_idx_constraint_oid(RelationGetRelid(rel), parentidx); if (OidIsValid(parentConstrOid) && OidIsValid(constrOid)) ConstraintSetParentConstraint(constrOid, InvalidOid, InvalidOid); index_close(idx, NoLock); } /* Update pg_class tuple */ classRel = table_open(RelationRelationId, RowExclusiveLock); tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(RelationGetRelid(partRel))); if (!HeapTupleIsValid(tuple)) elog(ERROR, "cache lookup failed for relation %u", RelationGetRelid(partRel)); Assert(((Form_pg_class) GETSTRUCT(tuple))->relispartition); /* Clear relpartbound and reset relispartition */ memset(new_val, 0, sizeof(new_val)); memset(new_null, false, sizeof(new_null)); memset(new_repl, false, sizeof(new_repl)); new_val[Anum_pg_class_relpartbound - 1] = (Datum) 0; new_null[Anum_pg_class_relpartbound - 1] = true; new_repl[Anum_pg_class_relpartbound - 1] = true; newtuple = heap_modify_tuple(tuple, RelationGetDescr(classRel), new_val, new_null, new_repl); ((Form_pg_class) GETSTRUCT(newtuple))->relispartition = false; CatalogTupleUpdate(classRel, &newtuple->t_self, newtuple); heap_freetuple(newtuple); table_close(classRel, RowExclusiveLock); /* * Drop identity property from all identity columns of partition. */ for (int attno = 0; attno < RelationGetNumberOfAttributes(partRel); attno++) { Form_pg_attribute attr = TupleDescAttr(partRel->rd_att, attno); if (!attr->attisdropped && attr->attidentity) ATExecDropIdentity(partRel, NameStr(attr->attname), false, AccessExclusiveLock, true, true); } if (OidIsValid(defaultPartOid)) { /* * If the relation being detached is the default partition itself, * remove it from the parent's pg_partitioned_table entry. * * If not, we must invalidate default partition's relcache entry, as * in StorePartitionBound: its partition constraint depends on every * other partition's partition constraint. */ if (RelationGetRelid(partRel) == defaultPartOid) update_default_partition_oid(RelationGetRelid(rel), InvalidOid); else CacheInvalidateRelcacheByRelid(defaultPartOid); } /* * Invalidate the parent's relcache so that the partition is no longer * included in its partition descriptor. */ CacheInvalidateRelcache(rel); /* * If the partition we just detached is partitioned itself, invalidate * relcache for all descendent partitions too to ensure that their * rd_partcheck expression trees are rebuilt; must lock partitions before * doing so, using the same lockmode as what partRel has been locked with * by the caller. */ if (partRel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) { List *children; children = find_all_inheritors(RelationGetRelid(partRel), AccessExclusiveLock, NULL); foreach(cell, children) { CacheInvalidateRelcacheByRelid(lfirst_oid(cell)); } } } /* * ALTER TABLE ... DETACH PARTITION ... FINALIZE * * To use when a DETACH PARTITION command previously did not run to * completion; this completes the detaching process. */ static ObjectAddress ATExecDetachPartitionFinalize(Relation rel, RangeVar *name) { Relation partRel; ObjectAddress address; Snapshot snap = GetActiveSnapshot(); partRel = table_openrv(name, AccessExclusiveLock); /* * Wait until existing snapshots are gone. This is important if the * second transaction of DETACH PARTITION CONCURRENTLY is canceled: the * user could immediately run DETACH FINALIZE without actually waiting for * existing transactions. We must not complete the detach action until * all such queries are complete (otherwise we would present them with an * inconsistent view of catalogs). */ WaitForOlderSnapshots(snap->xmin, false); DetachPartitionFinalize(rel, partRel, true, InvalidOid); ObjectAddressSet(address, RelationRelationId, RelationGetRelid(partRel)); table_close(partRel, NoLock); return address; } /* * DropClonedTriggersFromPartition * subroutine for ATExecDetachPartition to remove any triggers that were * cloned to the partition when it was created-as-partition or attached. * This undoes what CloneRowTriggersToPartition did. */ static void DropClonedTriggersFromPartition(Oid partitionId) { ScanKeyData skey; SysScanDesc scan; HeapTuple trigtup; Relation tgrel; ObjectAddresses *objects; objects = new_object_addresses(); /* * Scan pg_trigger to search for all triggers on this rel. */ ScanKeyInit(&skey, Anum_pg_trigger_tgrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(partitionId)); tgrel = table_open(TriggerRelationId, RowExclusiveLock); scan = systable_beginscan(tgrel, TriggerRelidNameIndexId, true, NULL, 1, &skey); while (HeapTupleIsValid(trigtup = systable_getnext(scan))) { Form_pg_trigger pg_trigger = (Form_pg_trigger) GETSTRUCT(trigtup); ObjectAddress trig; /* Ignore triggers that weren't cloned */ if (!OidIsValid(pg_trigger->tgparentid)) continue; /* * Ignore internal triggers that are implementation objects of foreign * keys, because these will be detached when the foreign keys * themselves are. */ if (OidIsValid(pg_trigger->tgconstrrelid)) continue; /* * This is ugly, but necessary: remove the dependency markings on the * trigger so that it can be removed. */ deleteDependencyRecordsForClass(TriggerRelationId, pg_trigger->oid, TriggerRelationId, DEPENDENCY_PARTITION_PRI); deleteDependencyRecordsForClass(TriggerRelationId, pg_trigger->oid, RelationRelationId, DEPENDENCY_PARTITION_SEC); /* remember this trigger to remove it below */ ObjectAddressSet(trig, TriggerRelationId, pg_trigger->oid); add_exact_object_address(&trig, objects); } /* make the dependency removal visible to the deletion below */ CommandCounterIncrement(); performMultipleDeletions(objects, DROP_RESTRICT, PERFORM_DELETION_INTERNAL); /* done */ free_object_addresses(objects); systable_endscan(scan); table_close(tgrel, RowExclusiveLock); } /* * Before acquiring lock on an index, acquire the same lock on the owning * table. */ struct AttachIndexCallbackState { Oid partitionOid; Oid parentTblOid; bool lockedParentTbl; }; static void RangeVarCallbackForAttachIndex(const RangeVar *rv, Oid relOid, Oid oldRelOid, void *arg) { struct AttachIndexCallbackState *state; Form_pg_class classform; HeapTuple tuple; state = (struct AttachIndexCallbackState *) arg; if (!state->lockedParentTbl) { LockRelationOid(state->parentTblOid, AccessShareLock); state->lockedParentTbl = true; } /* * If we previously locked some other heap, and the name we're looking up * no longer refers to an index on that relation, release the now-useless * lock. XXX maybe we should do *after* we verify whether the index does * not actually belong to the same relation ... */ if (relOid != oldRelOid && OidIsValid(state->partitionOid)) { UnlockRelationOid(state->partitionOid, AccessShareLock); state->partitionOid = InvalidOid; } /* Didn't find a relation, so no need for locking or permission checks. */ if (!OidIsValid(relOid)) return; tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relOid)); if (!HeapTupleIsValid(tuple)) return; /* concurrently dropped, so nothing to do */ classform = (Form_pg_class) GETSTRUCT(tuple); if (classform->relkind != RELKIND_PARTITIONED_INDEX && classform->relkind != RELKIND_INDEX) ereport(ERROR, (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), errmsg("\"%s\" is not an index", rv->relname))); ReleaseSysCache(tuple); /* * Since we need only examine the heap's tupledesc, an access share lock * on it (preventing any DDL) is sufficient. */ state->partitionOid = IndexGetRelation(relOid, false); LockRelationOid(state->partitionOid, AccessShareLock); } /* * ALTER INDEX i1 ATTACH PARTITION i2 */ static ObjectAddress ATExecAttachPartitionIdx(List **wqueue, Relation parentIdx, RangeVar *name) { Relation partIdx; Relation partTbl; Relation parentTbl; ObjectAddress address; Oid partIdxId; Oid currParent; struct AttachIndexCallbackState state; /* * We need to obtain lock on the index 'name' to modify it, but we also * need to read its owning table's tuple descriptor -- so we need to lock * both. To avoid deadlocks, obtain lock on the table before doing so on * the index. Furthermore, we need to examine the parent table of the * partition, so lock that one too. */ state.partitionOid = InvalidOid; state.parentTblOid = parentIdx->rd_index->indrelid; state.lockedParentTbl = false; partIdxId = RangeVarGetRelidExtended(name, AccessExclusiveLock, 0, RangeVarCallbackForAttachIndex, &state); /* Not there? */ if (!OidIsValid(partIdxId)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_OBJECT), errmsg("index \"%s\" does not exist", name->relname))); /* no deadlock risk: RangeVarGetRelidExtended already acquired the lock */ partIdx = relation_open(partIdxId, AccessExclusiveLock); /* we already hold locks on both tables, so this is safe: */ parentTbl = relation_open(parentIdx->rd_index->indrelid, AccessShareLock); partTbl = relation_open(partIdx->rd_index->indrelid, NoLock); ObjectAddressSet(address, RelationRelationId, RelationGetRelid(partIdx)); /* * Check if the index is already attached to the correct parent, * ultimately attempting one round of validation if already the case. */ currParent = partIdx->rd_rel->relispartition ? get_partition_parent(partIdxId, false) : InvalidOid; if (currParent != RelationGetRelid(parentIdx)) { IndexInfo *childInfo; IndexInfo *parentInfo; AttrMap *attmap; bool found; int i; PartitionDesc partDesc; Oid constraintOid, cldConstrId = InvalidOid; /* * If this partition already has an index attached, refuse the * operation. */ refuseDupeIndexAttach(parentIdx, partIdx, partTbl); if (OidIsValid(currParent)) ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("cannot attach index \"%s\" as a partition of index \"%s\"", RelationGetRelationName(partIdx), RelationGetRelationName(parentIdx)), errdetail("Index \"%s\" is already attached to another index.", RelationGetRelationName(partIdx)))); /* Make sure it indexes a partition of the other index's table */ partDesc = RelationGetPartitionDesc(parentTbl, true); found = false; for (i = 0; i < partDesc->nparts; i++) { if (partDesc->oids[i] == state.partitionOid) { found = true; break; } } if (!found) ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("cannot attach index \"%s\" as a partition of index \"%s\"", RelationGetRelationName(partIdx), RelationGetRelationName(parentIdx)), errdetail("Index \"%s\" is not an index on any partition of table \"%s\".", RelationGetRelationName(partIdx), RelationGetRelationName(parentTbl)))); /* Ensure the indexes are compatible */ childInfo = BuildIndexInfo(partIdx); parentInfo = BuildIndexInfo(parentIdx); attmap = build_attrmap_by_name(RelationGetDescr(partTbl), RelationGetDescr(parentTbl), false); if (!CompareIndexInfo(childInfo, parentInfo, partIdx->rd_indcollation, parentIdx->rd_indcollation, partIdx->rd_opfamily, parentIdx->rd_opfamily, attmap)) ereport(ERROR, (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), errmsg("cannot attach index \"%s\" as a partition of index \"%s\"", RelationGetRelationName(partIdx), RelationGetRelationName(parentIdx)), errdetail("The index definitions do not match."))); /* * If there is a constraint in the parent, make sure there is one in * the child too. */ constraintOid = get_relation_idx_constraint_oid(RelationGetRelid(parentTbl), RelationGetRelid(parentIdx)); if (OidIsValid(constraintOid)) { cldConstrId = get_relation_idx_constraint_oid(RelationGetRelid(partTbl), partIdxId); if (!OidIsValid(cldConstrId)) ereport(ERROR, (errcode(ERRCODE_INVALID_OBJECT_DEFINITION), errmsg("cannot attach index \"%s\" as a partition of index \"%s\"", RelationGetRelationName(partIdx), RelationGetRelationName(parentIdx)), errdetail("The index \"%s\" belongs to a constraint in table \"%s\" but no constraint exists for index \"%s\".", RelationGetRelationName(parentIdx), RelationGetRelationName(parentTbl), RelationGetRelationName(partIdx)))); } /* * If it's a primary key, make sure the columns in the partition are * NOT NULL. */ if (parentIdx->rd_index->indisprimary) verifyPartitionIndexNotNull(childInfo, partTbl); /* All good -- do it */ IndexSetParentIndex(partIdx, RelationGetRelid(parentIdx)); if (OidIsValid(constraintOid)) ConstraintSetParentConstraint(cldConstrId, constraintOid, RelationGetRelid(partTbl)); free_attrmap(attmap); validatePartitionedIndex(parentIdx, parentTbl); } else if (!parentIdx->rd_index->indisvalid) { /* * The index is attached, but the parent is still invalid; see if it * can be validated now. */ validatePartitionedIndex(parentIdx, parentTbl); } relation_close(parentTbl, AccessShareLock); /* keep these locks till commit */ relation_close(partTbl, NoLock); relation_close(partIdx, NoLock); return address; } /* * Verify whether the given partition already contains an index attached * to the given partitioned index. If so, raise an error. */ static void refuseDupeIndexAttach(Relation parentIdx, Relation partIdx, Relation partitionTbl) { Oid existingIdx; existingIdx = index_get_partition(partitionTbl, RelationGetRelid(parentIdx)); if (OidIsValid(existingIdx)) ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("cannot attach index \"%s\" as a partition of index \"%s\"", RelationGetRelationName(partIdx), RelationGetRelationName(parentIdx)), errdetail("Another index \"%s\" is already attached for partition \"%s\".", get_rel_name(existingIdx), RelationGetRelationName(partitionTbl)))); } /* * Verify whether the set of attached partition indexes to a parent index on * a partitioned table is complete. If it is, mark the parent index valid. * * This should be called each time a partition index is attached. */ static void validatePartitionedIndex(Relation partedIdx, Relation partedTbl) { Relation inheritsRel; SysScanDesc scan; ScanKeyData key; int tuples = 0; HeapTuple inhTup; bool updated = false; Assert(partedIdx->rd_rel->relkind == RELKIND_PARTITIONED_INDEX); /* * Scan pg_inherits for this parent index. Count each valid index we find * (verifying the pg_index entry for each), and if we reach the total * amount we expect, we can mark this parent index as valid. */ inheritsRel = table_open(InheritsRelationId, AccessShareLock); ScanKeyInit(&key, Anum_pg_inherits_inhparent, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(partedIdx))); scan = systable_beginscan(inheritsRel, InheritsParentIndexId, true, NULL, 1, &key); while ((inhTup = systable_getnext(scan)) != NULL) { Form_pg_inherits inhForm = (Form_pg_inherits) GETSTRUCT(inhTup); HeapTuple indTup; Form_pg_index indexForm; indTup = SearchSysCache1(INDEXRELID, ObjectIdGetDatum(inhForm->inhrelid)); if (!HeapTupleIsValid(indTup)) elog(ERROR, "cache lookup failed for index %u", inhForm->inhrelid); indexForm = (Form_pg_index) GETSTRUCT(indTup); if (indexForm->indisvalid) tuples += 1; ReleaseSysCache(indTup); } /* Done with pg_inherits */ systable_endscan(scan); table_close(inheritsRel, AccessShareLock); /* * If we found as many inherited indexes as the partitioned table has * partitions, we're good; update pg_index to set indisvalid. */ if (tuples == RelationGetPartitionDesc(partedTbl, true)->nparts) { Relation idxRel; HeapTuple indTup; Form_pg_index indexForm; idxRel = table_open(IndexRelationId, RowExclusiveLock); indTup = SearchSysCacheCopy1(INDEXRELID, ObjectIdGetDatum(RelationGetRelid(partedIdx))); if (!HeapTupleIsValid(indTup)) elog(ERROR, "cache lookup failed for index %u", RelationGetRelid(partedIdx)); indexForm = (Form_pg_index) GETSTRUCT(indTup); indexForm->indisvalid = true; updated = true; CatalogTupleUpdate(idxRel, &indTup->t_self, indTup); table_close(idxRel, RowExclusiveLock); heap_freetuple(indTup); } /* * If this index is in turn a partition of a larger index, validating it * might cause the parent to become valid also. Try that. */ if (updated && partedIdx->rd_rel->relispartition) { Oid parentIdxId, parentTblId; Relation parentIdx, parentTbl; /* make sure we see the validation we just did */ CommandCounterIncrement(); parentIdxId = get_partition_parent(RelationGetRelid(partedIdx), false); parentTblId = get_partition_parent(RelationGetRelid(partedTbl), false); parentIdx = relation_open(parentIdxId, AccessExclusiveLock); parentTbl = relation_open(parentTblId, AccessExclusiveLock); Assert(!parentIdx->rd_index->indisvalid); validatePartitionedIndex(parentIdx, parentTbl); relation_close(parentIdx, AccessExclusiveLock); relation_close(parentTbl, AccessExclusiveLock); } } /* * When attaching an index as a partition of a partitioned index which is a * primary key, verify that all the columns in the partition are marked NOT * NULL. */ static void verifyPartitionIndexNotNull(IndexInfo *iinfo, Relation partition) { for (int i = 0; i < iinfo->ii_NumIndexKeyAttrs; i++) { Form_pg_attribute att = TupleDescAttr(RelationGetDescr(partition), iinfo->ii_IndexAttrNumbers[i] - 1); if (!att->attnotnull) ereport(ERROR, errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("invalid primary key definition"), errdetail("Column \"%s\" of relation \"%s\" is not marked NOT NULL.", NameStr(att->attname), RelationGetRelationName(partition))); } } /* * Return an OID list of constraints that reference the given relation * that are marked as having a parent constraints. */ static List * GetParentedForeignKeyRefs(Relation partition) { Relation pg_constraint; HeapTuple tuple; SysScanDesc scan; ScanKeyData key[2]; List *constraints = NIL; /* * If no indexes, or no columns are referenceable by FKs, we can avoid the * scan. */ if (RelationGetIndexList(partition) == NIL || bms_is_empty(RelationGetIndexAttrBitmap(partition, INDEX_ATTR_BITMAP_KEY))) return NIL; /* Search for constraints referencing this table */ pg_constraint = table_open(ConstraintRelationId, AccessShareLock); ScanKeyInit(&key[0], Anum_pg_constraint_confrelid, BTEqualStrategyNumber, F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(partition))); ScanKeyInit(&key[1], Anum_pg_constraint_contype, BTEqualStrategyNumber, F_CHAREQ, CharGetDatum(CONSTRAINT_FOREIGN)); /* XXX This is a seqscan, as we don't have a usable index */ scan = systable_beginscan(pg_constraint, InvalidOid, true, NULL, 2, key); while ((tuple = systable_getnext(scan)) != NULL) { Form_pg_constraint constrForm = (Form_pg_constraint) GETSTRUCT(tuple); /* * We only need to process constraints that are part of larger ones. */ if (!OidIsValid(constrForm->conparentid)) continue; constraints = lappend_oid(constraints, constrForm->oid); } systable_endscan(scan); table_close(pg_constraint, AccessShareLock); return constraints; } /* * During DETACH PARTITION, verify that any foreign keys pointing to the * partitioned table would not become invalid. An error is raised if any * referenced values exist. */ static void ATDetachCheckNoForeignKeyRefs(Relation partition) { List *constraints; ListCell *cell; constraints = GetParentedForeignKeyRefs(partition); foreach(cell, constraints) { Oid constrOid = lfirst_oid(cell); HeapTuple tuple; Form_pg_constraint constrForm; Relation rel; Trigger trig = {0}; tuple = SearchSysCache1(CONSTROID, ObjectIdGetDatum(constrOid)); if (!HeapTupleIsValid(tuple)) elog(ERROR, "cache lookup failed for constraint %u", constrOid); constrForm = (Form_pg_constraint) GETSTRUCT(tuple); Assert(OidIsValid(constrForm->conparentid)); Assert(constrForm->confrelid == RelationGetRelid(partition)); /* prevent data changes into the referencing table until commit */ rel = table_open(constrForm->conrelid, ShareLock); trig.tgoid = InvalidOid; trig.tgname = NameStr(constrForm->conname); trig.tgenabled = TRIGGER_FIRES_ON_ORIGIN; trig.tgisinternal = true; trig.tgconstrrelid = RelationGetRelid(partition); trig.tgconstrindid = constrForm->conindid; trig.tgconstraint = constrForm->oid; trig.tgdeferrable = false; trig.tginitdeferred = false; /* we needn't fill in remaining fields */ RI_PartitionRemove_Check(&trig, rel, partition); ReleaseSysCache(tuple); table_close(rel, NoLock); } } /* * resolve column compression specification to compression method. */ static char GetAttributeCompression(Oid atttypid, const char *compression) { char cmethod; if (compression == NULL || strcmp(compression, "default") == 0) return InvalidCompressionMethod; /* * To specify a nondefault method, the column data type must be toastable. * Note this says nothing about whether the column's attstorage setting * permits compression; we intentionally allow attstorage and * attcompression to be independent. But with a non-toastable type, * attstorage could not be set to a value that would permit compression. * * We don't actually need to enforce this, since nothing bad would happen * if attcompression were non-default; it would never be consulted. But * it seems more user-friendly to complain about a certainly-useless * attempt to set the property. */ if (!TypeIsToastable(atttypid)) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("column data type %s does not support compression", format_type_be(atttypid)))); cmethod = CompressionNameToMethod(compression); if (!CompressionMethodIsValid(cmethod)) ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("invalid compression method \"%s\"", compression))); return cmethod; } /* * resolve column storage specification */ static char GetAttributeStorage(Oid atttypid, const char *storagemode) { char cstorage = 0; if (pg_strcasecmp(storagemode, "plain") == 0) cstorage = TYPSTORAGE_PLAIN; else if (pg_strcasecmp(storagemode, "external") == 0) cstorage = TYPSTORAGE_EXTERNAL; else if (pg_strcasecmp(storagemode, "extended") == 0) cstorage = TYPSTORAGE_EXTENDED; else if (pg_strcasecmp(storagemode, "main") == 0) cstorage = TYPSTORAGE_MAIN; else if (pg_strcasecmp(storagemode, "default") == 0) cstorage = get_typstorage(atttypid); else ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("invalid storage type \"%s\"", storagemode))); /* * safety check: do not allow toasted storage modes unless column datatype * is TOAST-aware. */ if (!(cstorage == TYPSTORAGE_PLAIN || TypeIsToastable(atttypid))) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("column data type %s can only have storage PLAIN", format_type_be(atttypid)))); return cstorage; } /* * buildExpressionExecutionStates: build the needed expression execution states * for new partition (newPartRel) checks and initialize expressions for * generated columns. All expressions should be created in "tab" * (AlteredTableInfo structure). */ static void buildExpressionExecutionStates(AlteredTableInfo *tab, Relation newPartRel, EState *estate) { /* * Build the needed expression execution states. Here, we expect only NOT * NULL and CHECK constraint. */ foreach_ptr(NewConstraint, con, tab->constraints) { switch (con->contype) { case CONSTR_CHECK: /* * We already expanded virtual expression in * createTableConstraints. */ con->qualstate = ExecPrepareExpr((Expr *) con->qual, estate); break; case CONSTR_NOTNULL: /* Nothing to do here. */ break; default: elog(ERROR, "unrecognized constraint type: %d", (int) con->contype); } } /* Expression already planned in createTableConstraints */ foreach_ptr(NewColumnValue, ex, tab->newvals) ex->exprstate = ExecInitExpr((Expr *) ex->expr, NULL); } /* * evaluateGeneratedExpressionsAndCheckConstraints: evaluate any generated * expressions for "tab" (AlteredTableInfo structure) whose inputs come from * the new tuple (insertslot) of the new partition (newPartRel). */ static void evaluateGeneratedExpressionsAndCheckConstraints(AlteredTableInfo *tab, Relation newPartRel, TupleTableSlot *insertslot, ExprContext *econtext) { econtext->ecxt_scantuple = insertslot; foreach_ptr(NewColumnValue, ex, tab->newvals) { if (!ex->is_generated) continue; insertslot->tts_values[ex->attnum - 1] = ExecEvalExpr(ex->exprstate, econtext, &insertslot->tts_isnull[ex->attnum - 1]); } foreach_ptr(NewConstraint, con, tab->constraints) { switch (con->contype) { case CONSTR_CHECK: if (!ExecCheck(con->qualstate, econtext)) ereport(ERROR, errcode(ERRCODE_CHECK_VIOLATION), errmsg("check constraint \"%s\" of relation \"%s\" is violated by some row", con->name, RelationGetRelationName(newPartRel)), errtableconstraint(newPartRel, con->name)); break; case CONSTR_NOTNULL: case CONSTR_FOREIGN: /* Nothing to do here */ break; default: elog(ERROR, "unrecognized constraint type: %d", (int) con->contype); } } } /* * getAttributesList: build a list of columns (ColumnDef) based on parent_rel */ static List * getAttributesList(Relation parent_rel) { AttrNumber parent_attno; TupleDesc modelDesc; List *colList = NIL; modelDesc = RelationGetDescr(parent_rel); for (parent_attno = 1; parent_attno <= modelDesc->natts; parent_attno++) { Form_pg_attribute attribute = TupleDescAttr(modelDesc, parent_attno - 1); ColumnDef *def; /* Ignore dropped columns in the parent. */ if (attribute->attisdropped) continue; def = makeColumnDef(NameStr(attribute->attname), attribute->atttypid, attribute->atttypmod, attribute->attcollation); def->is_not_null = attribute->attnotnull; /* Copy identity. */ def->identity = attribute->attidentity; /* Copy attgenerated. */ def->generated = attribute->attgenerated; def->storage = attribute->attstorage; /* Likewise, copy compression. */ if (CompressionMethodIsValid(attribute->attcompression)) def->compression = pstrdup(GetCompressionMethodName(attribute->attcompression)); else def->compression = NULL; /* Add to column list. */ colList = lappend(colList, def); } return colList; } /* * createTableConstraints: * create check constraints, default values, and generated values for newRel * based on parent_rel. tab is pending-work queue for newRel, we may need it in * MergePartitionsMoveRows. */ static void createTableConstraints(List **wqueue, AlteredTableInfo *tab, Relation parent_rel, Relation newRel) { TupleDesc tupleDesc; TupleConstr *constr; AttrMap *attmap; AttrNumber parent_attno; int ccnum; List *constraints = NIL; List *cookedConstraints = NIL; tupleDesc = RelationGetDescr(parent_rel); constr = tupleDesc->constr; if (!constr) return; /* * Construct a map from the parent relation's attnos to the child rel's. * This re-checks type match, etc, although it shouldn't be possible to * have a failure since both tables are locked. */ attmap = build_attrmap_by_name(RelationGetDescr(newRel), tupleDesc, false); /* Cycle for default values. */ for (parent_attno = 1; parent_attno <= tupleDesc->natts; parent_attno++) { Form_pg_attribute attribute = TupleDescAttr(tupleDesc, parent_attno - 1); /* Ignore dropped columns in the parent. */ if (attribute->attisdropped) continue; /* Copy the default, if present, and it should be copied. */ if (attribute->atthasdef) { Node *this_default = NULL; bool found_whole_row; AttrNumber num; Node *def; NewColumnValue *newval; if (attribute->attgenerated == ATTRIBUTE_GENERATED_VIRTUAL) this_default = build_generation_expression(parent_rel, attribute->attnum); else { this_default = TupleDescGetDefault(tupleDesc, attribute->attnum); if (this_default == NULL) elog(ERROR, "default expression not found for attribute %d of relation \"%s\"", attribute->attnum, RelationGetRelationName(parent_rel)); } num = attmap->attnums[parent_attno - 1]; def = map_variable_attnos(this_default, 1, 0, attmap, InvalidOid, &found_whole_row); if (found_whole_row && attribute->attgenerated != '\0') elog(ERROR, "cannot convert whole-row table reference"); /* Add a pre-cooked default expression. */ StoreAttrDefault(newRel, num, def, false); /* * Stored generated column expressions in parent_rel might * reference the tableoid. newRel, parent_rel tableoid clear is * not the same. If so, these stored generated columns require * recomputation for newRel within MergePartitionsMoveRows. */ if (attribute->attgenerated == ATTRIBUTE_GENERATED_STORED) { newval = palloc0_object(NewColumnValue); newval->attnum = num; newval->expr = expression_planner((Expr *) def); newval->is_generated = (attribute->attgenerated != '\0'); tab->newvals = lappend(tab->newvals, newval); } } } /* Cycle for CHECK constraints. */ for (ccnum = 0; ccnum < constr->num_check; ccnum++) { char *ccname = constr->check[ccnum].ccname; char *ccbin = constr->check[ccnum].ccbin; bool ccenforced = constr->check[ccnum].ccenforced; bool ccnoinherit = constr->check[ccnum].ccnoinherit; bool ccvalid = constr->check[ccnum].ccvalid; Node *ccbin_node; bool found_whole_row; Constraint *con; /* * The partitioned table can not have a NO INHERIT check constraint * (see StoreRelCheck function for details). */ Assert(!ccnoinherit); ccbin_node = map_variable_attnos(stringToNode(ccbin), 1, 0, attmap, InvalidOid, &found_whole_row); /* * For the moment we have to reject whole-row variables (as for CREATE * TABLE LIKE and inheritances). */ if (found_whole_row) elog(ERROR, "Constraint \"%s\" contains a whole-row reference to table \"%s\".", ccname, RelationGetRelationName(parent_rel)); con = makeNode(Constraint); con->contype = CONSTR_CHECK; con->conname = pstrdup(ccname); con->deferrable = false; con->initdeferred = false; con->is_enforced = ccenforced; con->skip_validation = !ccvalid; con->initially_valid = ccvalid; con->is_no_inherit = ccnoinherit; con->raw_expr = NULL; con->cooked_expr = nodeToString(ccbin_node); con->location = -1; constraints = lappend(constraints, con); } /* Install all CHECK constraints. */ cookedConstraints = AddRelationNewConstraints(newRel, NIL, constraints, false, true, false, NULL); /* Make the additional catalog changes visible. */ CommandCounterIncrement(); /* * parent_rel check constraint expression may reference tableoid, so later * in MergePartitionsMoveRows, we need to evaluate the check constraint * again for the newRel. We can check whether the check constraint * contains a tableoid reference via pull_varattnos. */ foreach_ptr(CookedConstraint, ccon, cookedConstraints) { if (!ccon->skip_validation) { Node *qual; Bitmapset *attnums = NULL; Assert(ccon->contype == CONSTR_CHECK); qual = expand_generated_columns_in_expr(ccon->expr, newRel, 1); pull_varattnos(qual, 1, &attnums); /* * Add a check only if it contains a tableoid * (TableOidAttributeNumber). */ if (bms_is_member(TableOidAttributeNumber - FirstLowInvalidHeapAttributeNumber, attnums)) { NewConstraint *newcon; newcon = palloc0_object(NewConstraint); newcon->name = ccon->name; newcon->contype = CONSTR_CHECK; newcon->qual = qual; tab->constraints = lappend(tab->constraints, newcon); } } } /* Don't need the cookedConstraints anymore. */ list_free_deep(cookedConstraints); /* Reproduce not-null constraints. */ if (constr->has_not_null) { List *nnconstraints; /* * The "include_noinh" argument is false because a partitioned table * can't have NO INHERIT constraint. */ nnconstraints = RelationGetNotNullConstraints(RelationGetRelid(parent_rel), false, false); Assert(list_length(nnconstraints) > 0); /* * We already set pg_attribute.attnotnull in createPartitionTable. No * need call set_attnotnull again. */ AddRelationNewConstraints(newRel, NIL, nnconstraints, false, true, false, NULL); } } /* * createPartitionTable: * * Create a new partition (newPartName) for the partitioned table (parent_rel). * ownerId is determined by the partition on which the operation is performed, * so it is passed separately. The new partition will inherit the access method * and persistence type from the parent table. * * Returns the created relation (locked in AccessExclusiveLock mode). */ static Relation createPartitionTable(List **wqueue, RangeVar *newPartName, Relation parent_rel, Oid ownerId) { Relation newRel; Oid newRelId; Oid existingRelid; Oid tablespaceId; TupleDesc descriptor; List *colList = NIL; Oid relamId; Oid namespaceId; AlteredTableInfo *new_partrel_tab; Form_pg_class parent_relform = parent_rel->rd_rel; /* If the existing rel is temp, it must belong to this session. */ if (RELATION_IS_OTHER_TEMP(parent_rel)) ereport(ERROR, errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot create as partition of temporary relation of another session")); /* Look up inheritance ancestors and generate the relation schema. */ colList = getAttributesList(parent_rel); /* Create a tuple descriptor from the relation schema. */ descriptor = BuildDescForRelation(colList); /* Look up the access method for the new relation. */ relamId = (parent_relform->relam != InvalidOid) ? parent_relform->relam : HEAP_TABLE_AM_OID; /* Look up the namespace in which we are supposed to create the relation. */ namespaceId = RangeVarGetAndCheckCreationNamespace(newPartName, NoLock, &existingRelid); if (OidIsValid(existingRelid)) ereport(ERROR, errcode(ERRCODE_DUPLICATE_TABLE), errmsg("relation \"%s\" already exists", newPartName->relname)); /* * We intended to create the partition with the same persistence as the * parent table, but we still need to recheck because that might be * affected by the search_path. If the parent is permanent, so must be * all of its partitions. */ if (parent_relform->relpersistence != RELPERSISTENCE_TEMP && newPartName->relpersistence == RELPERSISTENCE_TEMP) ereport(ERROR, errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot create a temporary relation as partition of permanent relation \"%s\"", RelationGetRelationName(parent_rel))); /* Permanent rels cannot be partitions belonging to a temporary parent. */ if (newPartName->relpersistence != RELPERSISTENCE_TEMP && parent_relform->relpersistence == RELPERSISTENCE_TEMP) ereport(ERROR, errcode(ERRCODE_WRONG_OBJECT_TYPE), errmsg("cannot create a permanent relation as partition of temporary relation \"%s\"", RelationGetRelationName(parent_rel))); /* * Select the tablespace for the new partition. Mirror the logic that * CREATE TABLE foo PARTITION OF ... uses in DefineRelation: take the * partitioned parent's explicit tablespace if it has one, otherwise take * default_tablespace into account, and finally use the database default. */ tablespaceId = parent_relform->reltablespace; if (!OidIsValid(tablespaceId)) tablespaceId = GetDefaultTablespace(newPartName->relpersistence, false); /* Check permissions except when using database's default */ if (OidIsValid(tablespaceId) && tablespaceId != MyDatabaseTableSpace) { AclResult aclresult; aclresult = object_aclcheck(TableSpaceRelationId, tablespaceId, GetUserId(), ACL_CREATE); if (aclresult != ACLCHECK_OK) aclcheck_error(aclresult, OBJECT_TABLESPACE, get_tablespace_name(tablespaceId)); } /* In all cases disallow placing user relations in pg_global */ if (tablespaceId == GLOBALTABLESPACE_OID) ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("only shared relations can be placed in pg_global tablespace"))); /* Create the relation. */ newRelId = heap_create_with_catalog(newPartName->relname, namespaceId, tablespaceId, InvalidOid, InvalidOid, InvalidOid, ownerId, relamId, descriptor, NIL, RELKIND_RELATION, newPartName->relpersistence, false, false, ONCOMMIT_NOOP, (Datum) 0, true, allowSystemTableMods, false, /* is_internal */ InvalidOid, NULL); /* * We must bump the command counter to make the newly-created relation * tuple visible for opening. */ CommandCounterIncrement(); /* * Create a TOAST table if the table needs one. MERGE/SPLIT PARTITION * moves rows from existing partition(s) into new partition(s), which may * carry out-of-line varlena values that the new relation must be able to * store. Also, the new partition must be able to receive out-of-line * varlena values after the DDL operation is complete. */ NewRelationCreateToastTable(newRelId, (Datum) 0); /* * Open the new partition with no lock, because we already have an * AccessExclusiveLock placed there after creation. */ newRel = table_open(newRelId, NoLock); /* Find or create a work queue entry for the newly created table. */ new_partrel_tab = ATGetQueueEntry(wqueue, newRel); /* Create constraints, default values, and generated values. */ createTableConstraints(wqueue, new_partrel_tab, parent_rel, newRel); /* * Need to call CommandCounterIncrement, so a fresh relcache entry has * newly installed constraint info. */ CommandCounterIncrement(); return newRel; } /* * MergePartitionsMoveRows: scan partitions to be merged (mergingPartitions) * of the partitioned table and move rows into the new partition * (newPartRel). We also verify check constraints against these rows. */ static void MergePartitionsMoveRows(List **wqueue, List *mergingPartitions, Relation newPartRel) { CommandId mycid; EState *estate; AlteredTableInfo *tab; ListCell *ltab; /* The FSM is empty, so don't bother using it. */ uint32 ti_options = TABLE_INSERT_SKIP_FSM; BulkInsertState bistate; /* state of bulk inserts for partition */ TupleTableSlot *dstslot; /* Find the work queue entry for the new partition table: newPartRel. */ tab = ATGetQueueEntry(wqueue, newPartRel); /* Generate the constraint and default execution states. */ estate = CreateExecutorState(); buildExpressionExecutionStates(tab, newPartRel, estate); mycid = GetCurrentCommandId(true); /* Prepare a BulkInsertState for table_tuple_insert. */ bistate = GetBulkInsertState(); /* Create the necessary tuple slot. */ dstslot = table_slot_create(newPartRel, NULL); foreach_oid(merging_oid, mergingPartitions) { ExprContext *econtext; TupleTableSlot *srcslot; TupleConversionMap *tuple_map; TableScanDesc scan; MemoryContext oldCxt; Snapshot snapshot; Relation mergingPartition; econtext = GetPerTupleExprContext(estate); /* * Partition is already locked in the transformPartitionCmdForMerge * function. */ mergingPartition = table_open(merging_oid, NoLock); /* Create a source tuple slot for the partition being merged. */ srcslot = table_slot_create(mergingPartition, NULL); /* * Map computing for moving attributes of the merged partition to the * new partition. */ tuple_map = convert_tuples_by_name(RelationGetDescr(mergingPartition), RelationGetDescr(newPartRel)); /* Scan through the rows. */ snapshot = RegisterSnapshot(GetLatestSnapshot()); scan = table_beginscan(mergingPartition, snapshot, 0, NULL, SO_NONE); /* * Switch to per-tuple memory context and reset it for each tuple * produced, so we don't leak memory. */ oldCxt = MemoryContextSwitchTo(GetPerTupleMemoryContext(estate)); while (table_scan_getnextslot(scan, ForwardScanDirection, srcslot)) { TupleTableSlot *insertslot; CHECK_FOR_INTERRUPTS(); if (tuple_map) { /* Need to use a map to copy attributes. */ insertslot = execute_attr_map_slot(tuple_map->attrMap, srcslot, dstslot); } else { slot_getallattrs(srcslot); /* Copy attributes directly. */ insertslot = dstslot; ExecClearTuple(insertslot); memcpy(insertslot->tts_values, srcslot->tts_values, sizeof(Datum) * srcslot->tts_nvalid); memcpy(insertslot->tts_isnull, srcslot->tts_isnull, sizeof(bool) * srcslot->tts_nvalid); ExecStoreVirtualTuple(insertslot); } /* * Constraints and GENERATED expressions might reference the * tableoid column, so fill tts_tableOid with the desired value. * (We must do this each time, because it gets overwritten with * newrel's OID during storing.) */ insertslot->tts_tableOid = RelationGetRelid(newPartRel); /* * Now, evaluate any generated expressions whose inputs come from * the new tuple. We assume these columns won't reference each * other, so that there's no ordering dependency. */ evaluateGeneratedExpressionsAndCheckConstraints(tab, newPartRel, insertslot, econtext); /* Write the tuple out to the new relation. */ table_tuple_insert(newPartRel, insertslot, mycid, ti_options, bistate); ResetExprContext(econtext); } MemoryContextSwitchTo(oldCxt); table_endscan(scan); UnregisterSnapshot(snapshot); if (tuple_map) free_conversion_map(tuple_map); ExecDropSingleTupleTableSlot(srcslot); table_close(mergingPartition, NoLock); } FreeExecutorState(estate); ExecDropSingleTupleTableSlot(dstslot); FreeBulkInsertState(bistate); table_finish_bulk_insert(newPartRel, ti_options); /* * We don't need to process this newPartRel since we already processed it * here, so delete the ALTER TABLE queue for it. */ foreach(ltab, *wqueue) { tab = (AlteredTableInfo *) lfirst(ltab); if (tab->relid == RelationGetRelid(newPartRel)) { *wqueue = list_delete_cell(*wqueue, ltab); break; } } } /* * detachPartitionTable: detach partition "child_rel" from partitioned table * "parent_rel" with default partition identifier "defaultPartOid" */ static void detachPartitionTable(Relation parent_rel, Relation child_rel, Oid defaultPartOid) { /* Remove the pg_inherits row first. */ RemoveInheritance(child_rel, parent_rel, false); /* * Detaching the partition might involve TOAST table access, so ensure we * have a valid snapshot. */ PushActiveSnapshot(GetTransactionSnapshot()); /* Do the final part of detaching. */ DetachPartitionFinalize(parent_rel, child_rel, false, defaultPartOid); PopActiveSnapshot(); } /* * equal_oid_lists: return true if two OID lists, each sorted in ascending * order, contain the same OIDs in the same order. */ static bool equal_oid_lists(const List *a, const List *b) { ListCell *la, *lb; if (list_length(a) != list_length(b)) return false; forboth(la, a, lb, b) { if (lfirst_oid(la) != lfirst_oid(lb)) return false; } return true; } /* * Comparator for list_sort() on a list of PartitionIndexExtDepEntry *. * Orders by parentIndexOid, then by indexOid as a tiebreaker so conflict * reports for different parent indexes are deterministic. */ static int cmp_partition_index_ext_dep(const ListCell *a, const ListCell *b) { const PartitionIndexExtDepEntry *ea = lfirst(a); const PartitionIndexExtDepEntry *eb = lfirst(b); if (ea->parentIndexOid != eb->parentIndexOid) return pg_cmp_u32(ea->parentIndexOid, eb->parentIndexOid); return pg_cmp_u32(ea->indexOid, eb->indexOid); } /* * collectPartitionIndexExtDeps: collect extension dependencies from indexes * on the given partitions. * * For each partition index that has a parent partitioned index, we collect * extension dependencies. All source partition indexes sharing the same * parent partitioned index must depend on exactly the same set of * extensions; otherwise an error is raised so that we neither silently drop * nor silently add dependencies on the merged partition's index. * * Indexes that don't have a parent partitioned index (i.e., indexes created * directly on a partition without a corresponding parent index) are skipped. * * The returned list is sorted by parentIndexOid with exactly one entry per * parent partitioned index, so applyPartitionIndexExtDeps() can scan it * linearly. */ static List * collectPartitionIndexExtDeps(List *partitionOids) { List *collected = NIL; List *result = NIL; PartitionIndexExtDepEntry *prev = NULL; /* * Phase 1: collect one entry per (partition index -> parent index) pair, * with its extension dependency OIDs sorted ascending. */ foreach_oid(partOid, partitionOids) { Relation partRel; List *indexList; /* * Use NoLock since the caller already holds AccessExclusiveLock on * these partitions. */ partRel = table_open(partOid, NoLock); indexList = RelationGetIndexList(partRel); foreach_oid(indexOid, indexList) { Oid parentIndexOid; PartitionIndexExtDepEntry *entry; if (!get_rel_relispartition(indexOid)) continue; parentIndexOid = get_partition_parent(indexOid, true); if (!OidIsValid(parentIndexOid)) continue; entry = palloc(sizeof(PartitionIndexExtDepEntry)); entry->parentIndexOid = parentIndexOid; entry->indexOid = indexOid; entry->extensionOids = getAutoExtensionsOfObject(RelationRelationId, indexOid); list_sort(entry->extensionOids, list_oid_cmp); collected = lappend(collected, entry); } list_free(indexList); table_close(partRel, NoLock); } /* * Phase 2: sort by parentIndexOid so entries sharing a parent index sit * adjacent. */ list_sort(collected, cmp_partition_index_ext_dep); /* * Phase 3: single linear pass verifying that adjacent entries sharing a * parent index have identical extension dependencies, and keeping one * representative entry per parent index. */ foreach_ptr(PartitionIndexExtDepEntry, entry, collected) { if (prev != NULL && prev->parentIndexOid == entry->parentIndexOid) { if (!equal_oid_lists(prev->extensionOids, entry->extensionOids)) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot merge partitions with conflicting extension dependencies"), errdetail("Partition indexes \"%s\" and \"%s\" depend on different extensions.", get_rel_name(prev->indexOid), get_rel_name(entry->indexOid)))); /* Duplicate entry for the same parent index; discard. */ list_free(entry->extensionOids); pfree(entry); continue; } result = lappend(result, entry); prev = entry; } list_free(collected); return result; } /* * applyPartitionIndexExtDeps: apply collected extension dependencies to * indexes on a new partition. * * For each index on the new partition, look up its parent index in the * extDepState list. If found, record extension dependencies on the new index. * extDepState is sorted by parentIndexOid, so the inner scan can bail out * as soon as it passes the target OID. */ static void applyPartitionIndexExtDeps(Oid newPartOid, List *extDepState) { Relation partRel; List *indexList; if (extDepState == NIL) return; /* * Use NoLock since the caller already holds AccessExclusiveLock on the * new partition. */ partRel = table_open(newPartOid, NoLock); indexList = RelationGetIndexList(partRel); foreach_oid(indexOid, indexList) { Oid parentIdxOid; if (!get_rel_relispartition(indexOid)) continue; parentIdxOid = get_partition_parent(indexOid, true); if (!OidIsValid(parentIdxOid)) continue; foreach_ptr(PartitionIndexExtDepEntry, entry, extDepState) { ObjectAddress indexAddr; if (entry->parentIndexOid > parentIdxOid) break; if (entry->parentIndexOid < parentIdxOid) continue; ObjectAddressSet(indexAddr, RelationRelationId, indexOid); foreach_oid(extOid, entry->extensionOids) { ObjectAddress extAddr; ObjectAddressSet(extAddr, ExtensionRelationId, extOid); recordDependencyOn(&indexAddr, &extAddr, DEPENDENCY_AUTO_EXTENSION); } break; } } list_free(indexList); table_close(partRel, NoLock); } /* * freePartitionIndexExtDeps: free memory allocated by collectPartitionIndexExtDeps. */ static void freePartitionIndexExtDeps(List *extDepState) { foreach_ptr(PartitionIndexExtDepEntry, entry, extDepState) { list_free(entry->extensionOids); pfree(entry); } list_free(extDepState); } /* * ALTER TABLE <name> MERGE PARTITIONS <partition-list> INTO <partition-name> */ static void ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel, PartitionCmd *cmd, AlterTableUtilityContext *context) { Relation newPartRel; List *mergingPartitions = NIL; List *extDepState = NIL; Oid defaultPartOid; Oid existingRelid; Oid ownerId = InvalidOid; Oid save_userid; int save_sec_context; int save_nestlevel; /* * Check ownership of merged partitions - partitions with different owners * cannot be merged. Also, collect the OIDs of these partitions during the * check. */ foreach_node(RangeVar, name, cmd->partlist) { Relation mergingPartition; /* * We are going to detach and remove this partition. We already took * AccessExclusiveLock lock on transformPartitionCmdForMerge, so here, * NoLock is fine. */ mergingPartition = table_openrv_extended(name, NoLock, false); Assert(CheckRelationLockedByMe(mergingPartition, AccessExclusiveLock, false)); if (OidIsValid(ownerId)) { /* Do the partitions being merged have different owners? */ if (ownerId != mergingPartition->rd_rel->relowner) ereport(ERROR, errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("partitions being merged have different owners")); } else ownerId = mergingPartition->rd_rel->relowner; /* Store the next merging partition into the list. */ mergingPartitions = lappend_oid(mergingPartitions, RelationGetRelid(mergingPartition)); table_close(mergingPartition, NoLock); } /* Look up the existing relation by the new partition name. */ RangeVarGetAndCheckCreationNamespace(cmd->name, NoLock, &existingRelid); /* * Check if this name is already taken. This helps us to detect the * situation when one of the merging partitions has the same name as the * new partition. Otherwise, this would fail later on anyway, but * catching this here allows us to emit a nicer error message. */ if (OidIsValid(existingRelid)) { if (list_member_oid(mergingPartitions, existingRelid)) { /* * The new partition has the same name as one of the merging * partitions. */ char tmpRelName[NAMEDATALEN]; /* Generate a temporary name. */ sprintf(tmpRelName, "merge-%u-%X-tmp", RelationGetRelid(rel), MyProcPid); /* * Rename the existing partition with a temporary name, leaving it * free for the new partition. We don't need to care about this * in the future because we're going to eventually drop the * existing partition anyway. */ RenameRelationInternal(existingRelid, tmpRelName, true, false); /* * We must bump the command counter to make the new partition * tuple visible for rename. */ CommandCounterIncrement(); } else { ereport(ERROR, errcode(ERRCODE_DUPLICATE_TABLE), errmsg("relation \"%s\" already exists", cmd->name->relname)); } } defaultPartOid = get_default_oid_from_partdesc(RelationGetPartitionDesc(rel, true)); /* * Collect extension dependencies from indexes on the merging partitions. * We must do this before detaching them, so we can restore the * dependencies on the new partition's indexes later. */ extDepState = collectPartitionIndexExtDeps(mergingPartitions); /* Detach all merging partitions. */ foreach_oid(mergingPartitionOid, mergingPartitions) { Relation child_rel; child_rel = table_open(mergingPartitionOid, NoLock); detachPartitionTable(rel, child_rel, defaultPartOid); table_close(child_rel, NoLock); } /* * Perform a preliminary check to determine whether it's safe to drop all * merging partitions before we actually do so later. After merging rows * into the new partitions via MergePartitionsMoveRows, all old partitions * need to be dropped. However, since the drop behavior is DROP_RESTRICT * and the merge process (MergePartitionsMoveRows) can be time-consuming, * performing an early check on the drop eligibility of old partitions is * preferable. */ foreach_oid(mergingPartitionOid, mergingPartitions) { ObjectAddress object; /* Get oid of the later to be dropped relation. */ object.objectId = mergingPartitionOid; object.classId = RelationRelationId; object.objectSubId = 0; performDeletionCheck(&object, DROP_RESTRICT, 0); } /* * Create a table for the new partition, using the partitioned table as a * model. */ Assert(OidIsValid(ownerId)); newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId); /* * Switch to the table owner's userid, so that any index functions are run * as that user. Also, lockdown security-restricted operations and * arrange to make GUC variable changes local to this command. * * Need to do it after determining the namespace in the * createPartitionTable() call. */ GetUserIdAndSecContext(&save_userid, &save_sec_context); SetUserIdAndSecContext(ownerId, save_sec_context | SECURITY_RESTRICTED_OPERATION); save_nestlevel = NewGUCNestLevel(); RestrictSearchPath(); /* Copy data from merged partitions to the new partition. */ MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel); /* Drop the current partitions before attaching the new one. */ foreach_oid(mergingPartitionOid, mergingPartitions) { ObjectAddress object; object.objectId = mergingPartitionOid; object.classId = RelationRelationId; object.objectSubId = 0; performDeletion(&object, DROP_RESTRICT, 0); } list_free(mergingPartitions); /* * Attach a new partition to the partitioned table. wqueue = NULL: * verification for each cloned constraint is not needed. */ attachPartitionTable(NULL, rel, newPartRel, cmd->bound); /* * Apply extension dependencies to the new partition's indexes. This * preserves any "DEPENDS ON EXTENSION" settings from the merged * partitions. */ applyPartitionIndexExtDeps(RelationGetRelid(newPartRel), extDepState); freePartitionIndexExtDeps(extDepState); /* Keep the lock until commit. */ table_close(newPartRel, NoLock); /* Roll back any GUC changes executed by index functions. */ AtEOXact_GUC(false, save_nestlevel); /* Restore the userid and security context. */ SetUserIdAndSecContext(save_userid, save_sec_context); } /* * Struct with the context of the new partition for inserting rows from the * split partition. */ typedef struct SplitPartitionContext { ExprState *partqualstate; /* expression for checking a slot for a * partition (NULL for DEFAULT partition) */ BulkInsertState bistate; /* state of bulk inserts for partition */ TupleTableSlot *dstslot; /* slot for inserting row into partition */ AlteredTableInfo *tab; /* structure with generated column expressions * and check constraint expressions. */ Relation partRel; /* relation for partition */ } SplitPartitionContext; /* * createSplitPartitionContext: create context for partition and fill it */ static SplitPartitionContext * createSplitPartitionContext(Relation partRel) { SplitPartitionContext *pc; pc = palloc0_object(SplitPartitionContext); pc->partRel = partRel; /* * Prepare a BulkInsertState for table_tuple_insert. The FSM is empty, so * don't bother using it. */ pc->bistate = GetBulkInsertState(); /* Create a destination tuple slot for the new partition. */ pc->dstslot = table_slot_create(pc->partRel, NULL); return pc; } /* * deleteSplitPartitionContext: delete context for partition */ static void deleteSplitPartitionContext(SplitPartitionContext *pc, List **wqueue, uint32 ti_options) { ListCell *ltab; ExecDropSingleTupleTableSlot(pc->dstslot); FreeBulkInsertState(pc->bistate); table_finish_bulk_insert(pc->partRel, ti_options); /* * We don't need to process this pc->partRel so delete the ALTER TABLE * queue of it. */ foreach(ltab, *wqueue) { AlteredTableInfo *tab = (AlteredTableInfo *) lfirst(ltab); if (tab->relid == RelationGetRelid(pc->partRel)) { *wqueue = list_delete_cell(*wqueue, ltab); break; } } pfree(pc); } /* * SplitPartitionMoveRows: scan split partition (splitRel) of partitioned table * (rel) and move rows into new partitions. * * New partitions description: * partlist: list of pointers to SinglePartitionSpec structures. It contains * the partition specification details for all new partitions. * newPartRels: list of Relations, new partitions created in * ATExecSplitPartition. */ static void SplitPartitionMoveRows(List **wqueue, Relation rel, Relation splitRel, List *partlist, List *newPartRels) { /* The FSM is empty, so don't bother using it. */ uint32 ti_options = TABLE_INSERT_SKIP_FSM; CommandId mycid; EState *estate; ListCell *listptr, *listptr2; TupleTableSlot *srcslot; ExprContext *econtext; TableScanDesc scan; Snapshot snapshot; MemoryContext oldCxt; List *partContexts = NIL; TupleConversionMap *tuple_map; SplitPartitionContext *defaultPartCtx = NULL, *pc; mycid = GetCurrentCommandId(true); estate = CreateExecutorState(); forboth(listptr, partlist, listptr2, newPartRels) { SinglePartitionSpec *sps = (SinglePartitionSpec *) lfirst(listptr); pc = createSplitPartitionContext((Relation) lfirst(listptr2)); /* Find the work queue entry for the new partition table: newPartRel. */ pc->tab = ATGetQueueEntry(wqueue, pc->partRel); buildExpressionExecutionStates(pc->tab, pc->partRel, estate); if (sps->bound->is_default) { /* * We should not create a structure to check the partition * constraint for the new DEFAULT partition. */ defaultPartCtx = pc; } else { List *partConstraint; /* Build expression execution states for partition check quals. */ partConstraint = get_qual_from_partbound(rel, sps->bound); partConstraint = (List *) eval_const_expressions(NULL, (Node *) partConstraint); /* Make a boolean expression for ExecCheck(). */ partConstraint = list_make1(make_ands_explicit(partConstraint)); /* * Map the vars in the constraint expression from rel's attnos to * splitRel's. */ partConstraint = map_partition_varattnos(partConstraint, 1, splitRel, rel); pc->partqualstate = ExecPrepareExpr((Expr *) linitial(partConstraint), estate); Assert(pc->partqualstate != NULL); } /* Store partition context into a list. */ partContexts = lappend(partContexts, pc); } econtext = GetPerTupleExprContext(estate); /* Create the necessary tuple slot. */ srcslot = table_slot_create(splitRel, NULL); /* * Map computing for moving attributes of the split partition to the new * partition (for the first new partition, but other new partitions can * use the same map). */ pc = (SplitPartitionContext *) lfirst(list_head(partContexts)); tuple_map = convert_tuples_by_name(RelationGetDescr(splitRel), RelationGetDescr(pc->partRel)); /* Scan through the rows. */ snapshot = RegisterSnapshot(GetLatestSnapshot()); scan = table_beginscan(splitRel, snapshot, 0, NULL, SO_NONE); /* * Switch to per-tuple memory context and reset it for each tuple * produced, so we don't leak memory. */ oldCxt = MemoryContextSwitchTo(GetPerTupleMemoryContext(estate)); while (table_scan_getnextslot(scan, ForwardScanDirection, srcslot)) { bool found = false; TupleTableSlot *insertslot; CHECK_FOR_INTERRUPTS(); econtext->ecxt_scantuple = srcslot; /* Search partition for the current slot, srcslot. */ foreach(listptr, partContexts) { pc = (SplitPartitionContext *) lfirst(listptr); /* skip DEFAULT partition */ if (pc->partqualstate && ExecCheck(pc->partqualstate, econtext)) { found = true; break; } } if (!found) { /* Use the DEFAULT partition if it exists. */ if (defaultPartCtx) pc = defaultPartCtx; else ereport(ERROR, errcode(ERRCODE_CHECK_VIOLATION), errmsg("cannot find partition for split partition row"), errtable(splitRel)); } if (tuple_map) { /* Need to use a map to copy attributes. */ insertslot = execute_attr_map_slot(tuple_map->attrMap, srcslot, pc->dstslot); } else { /* Extract data from the old tuple. */ slot_getallattrs(srcslot); /* Copy attributes directly. */ insertslot = pc->dstslot; ExecClearTuple(insertslot); memcpy(insertslot->tts_values, srcslot->tts_values, sizeof(Datum) * srcslot->tts_nvalid); memcpy(insertslot->tts_isnull, srcslot->tts_isnull, sizeof(bool) * srcslot->tts_nvalid); ExecStoreVirtualTuple(insertslot); } /* * Constraints and GENERATED expressions might reference the tableoid * column, so fill tts_tableOid with the desired value. (We must do * this each time, because it gets overwritten with newrel's OID * during storing.) */ insertslot->tts_tableOid = RelationGetRelid(pc->partRel); /* * Now, evaluate any generated expressions whose inputs come from the * new tuple. We assume these columns won't reference each other, so * that there's no ordering dependency. */ evaluateGeneratedExpressionsAndCheckConstraints(pc->tab, pc->partRel, insertslot, econtext); /* Write the tuple out to the new relation. */ table_tuple_insert(pc->partRel, insertslot, mycid, ti_options, pc->bistate); ResetExprContext(econtext); } MemoryContextSwitchTo(oldCxt); table_endscan(scan); UnregisterSnapshot(snapshot); if (tuple_map) free_conversion_map(tuple_map); ExecDropSingleTupleTableSlot(srcslot); FreeExecutorState(estate); foreach_ptr(SplitPartitionContext, spc, partContexts) deleteSplitPartitionContext(spc, wqueue, ti_options); } /* * ALTER TABLE <name> SPLIT PARTITION <partition-name> INTO <partition-list> */ static void ATExecSplitPartition(List **wqueue, AlteredTableInfo *tab, Relation rel, PartitionCmd *cmd, AlterTableUtilityContext *context) { Relation splitRel; Oid splitRelOid; ListCell *listptr, *listptr2; bool isSameName = false; char tmpRelName[NAMEDATALEN]; List *newPartRels = NIL; List *extDepState = NIL; ObjectAddress object; Oid defaultPartOid; Oid save_userid; int save_sec_context; int save_nestlevel; List *splitPartList; defaultPartOid = get_default_oid_from_partdesc(RelationGetPartitionDesc(rel, true)); /* * Partition is already locked in the transformPartitionCmdForSplit * function. */ splitRel = table_openrv(cmd->name, NoLock); splitRelOid = RelationGetRelid(splitRel); /* Check descriptions of new partitions. */ foreach_node(SinglePartitionSpec, sps, cmd->partlist) { Oid existingRelid; /* Look up the existing relation by the new partition name. */ RangeVarGetAndCheckCreationNamespace(sps->name, NoLock, &existingRelid); /* * This would fail later on anyway if the relation already exists. But * by catching it here, we can emit a nicer error message. */ if (existingRelid == splitRelOid && !isSameName) /* One new partition can have the same name as a split partition. */ isSameName = true; else if (OidIsValid(existingRelid)) ereport(ERROR, errcode(ERRCODE_DUPLICATE_TABLE), errmsg("relation \"%s\" already exists", sps->name->relname)); } /* * Collect extension dependencies from indexes on the split partition. We * must do this before detaching it, so we can restore the dependencies on * the new partitions' indexes later. */ splitPartList = list_make1_oid(splitRelOid); extDepState = collectPartitionIndexExtDeps(splitPartList); list_free(splitPartList); /* Detach the split partition. */ detachPartitionTable(rel, splitRel, defaultPartOid); /* * Perform a preliminary check to determine whether it's safe to drop the * split partition before we actually do so later. After merging rows into * the new partitions via SplitPartitionMoveRows, all old partitions need * to be dropped. However, since the drop behavior is DROP_RESTRICT and * the merge process (SplitPartitionMoveRows) can be time-consuming, * performing an early check on the drop eligibility of old partitions is * preferable. */ object.objectId = splitRelOid; object.classId = RelationRelationId; object.objectSubId = 0; performDeletionCheck(&object, DROP_RESTRICT, 0); /* * If a new partition has the same name as the split partition, then we * should rename the split partition to reuse its name. */ if (isSameName) { /* * We must bump the command counter to make the split partition tuple * visible for renaming. */ CommandCounterIncrement(); /* Rename partition. */ sprintf(tmpRelName, "split-%u-%X-tmp", RelationGetRelid(rel), MyProcPid); RenameRelationInternal(splitRelOid, tmpRelName, true, false); /* * We must bump the command counter to make the split partition tuple * visible after renaming. */ CommandCounterIncrement(); } /* Create new partitions (like a split partition), without indexes. */ foreach_node(SinglePartitionSpec, sps, cmd->partlist) { Relation newPartRel; newPartRel = createPartitionTable(wqueue, sps->name, rel, splitRel->rd_rel->relowner); newPartRels = lappend(newPartRels, newPartRel); } /* * Switch to the table owner's userid, so that any index functions are run * as that user. Also, lockdown security-restricted operations and * arrange to make GUC variable changes local to this command. * * Need to do it after determining the namespace in the * createPartitionTable() call. */ GetUserIdAndSecContext(&save_userid, &save_sec_context); SetUserIdAndSecContext(splitRel->rd_rel->relowner, save_sec_context | SECURITY_RESTRICTED_OPERATION); save_nestlevel = NewGUCNestLevel(); RestrictSearchPath(); /* Copy data from the split partition to the new partitions. */ SplitPartitionMoveRows(wqueue, rel, splitRel, cmd->partlist, newPartRels); /* Keep the lock until commit. */ table_close(splitRel, NoLock); /* Attach new partitions to the partitioned table. */ forboth(listptr, cmd->partlist, listptr2, newPartRels) { SinglePartitionSpec *sps = (SinglePartitionSpec *) lfirst(listptr); Relation newPartRel = (Relation) lfirst(listptr2); /* * wqueue = NULL: verification for each cloned constraint is not * needed. */ attachPartitionTable(NULL, rel, newPartRel, sps->bound); /* * Apply extension dependencies to the new partition's indexes. This * preserves any "DEPENDS ON EXTENSION" settings from the split * partition. */ applyPartitionIndexExtDeps(RelationGetRelid(newPartRel), extDepState); /* Keep the lock until commit. */ table_close(newPartRel, NoLock); } freePartitionIndexExtDeps(extDepState); /* Drop the split partition. */ object.classId = RelationRelationId; object.objectId = splitRelOid; object.objectSubId = 0; /* Probably DROP_CASCADE is not needed. */ performDeletion(&object, DROP_RESTRICT, 0); /* Roll back any GUC changes executed by index functions. */ AtEOXact_GUC(false, save_nestlevel); /* Restore the userid and security context. */ SetUserIdAndSecContext(save_userid, save_sec_context); }