contrib/test_decoding/expected/twophase.out - master - githubmirror/postgres

contrib/test_decoding/expected/twophase.out
271 строка10 KB
Masahiko Sawada
Fix logical decoding of empty prepared transactions.
28 июл 2026, 22:33
28 июл 2026, 22:33acaa100
-- Test prepared transactions. When two-phase-commit is enabled, transactions are
-- decoded at PREPARE time rather than at COMMIT PREPARED time.
SET synchronous_commit = on;
SELECT 'init' FROM pg_create_logical_replication_slot('regression_slot', 'test_decoding', false, true);
 ?column? 
----------
 init
(1 row)

CREATE TABLE test_prepared1(id integer primary key);
CREATE TABLE test_prepared2(id integer primary key);
-- Test that decoding happens at PREPARE time when two-phase-commit is enabled.
-- Decoding after COMMIT PREPARED must have all the commands in the transaction.
BEGIN;
INSERT INTO test_prepared1 VALUES (1);
INSERT INTO test_prepared1 VALUES (2);
-- should show nothing because the xact has not been prepared yet.
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
 data 
------
(0 rows)

PREPARE TRANSACTION 'test_prepared#1';
-- should show both the above inserts and the PREPARE TRANSACTION.
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
                        data                        
----------------------------------------------------
 BEGIN
 table public.test_prepared1: INSERT: id[integer]:1
 table public.test_prepared1: INSERT: id[integer]:2
 PREPARE TRANSACTION 'test_prepared#1'
(4 rows)

COMMIT PREPARED 'test_prepared#1';
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
               data                
-----------------------------------
 COMMIT PREPARED 'test_prepared#1'
(1 row)

-- Test that rollback of a prepared xact is decoded.
BEGIN;
INSERT INTO test_prepared1 VALUES (3);
PREPARE TRANSACTION 'test_prepared#2';
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
                        data                        
----------------------------------------------------
 BEGIN
 table public.test_prepared1: INSERT: id[integer]:3
 PREPARE TRANSACTION 'test_prepared#2'
(3 rows)

ROLLBACK PREPARED 'test_prepared#2';
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
                data                 
-------------------------------------
 ROLLBACK PREPARED 'test_prepared#2'
(1 row)

-- Test prepare of a xact containing ddl. Leaving xact uncommitted for next test.
BEGIN;
ALTER TABLE test_prepared1 ADD COLUMN data text;
INSERT INTO test_prepared1 VALUES (4, 'frakbar');
PREPARE TRANSACTION 'test_prepared#3';
-- confirm that exclusive lock from the ALTER command is held on test_prepared1 table
SELECT 'test_prepared_1' AS relation, locktype, mode
FROM pg_locks
WHERE locktype = 'relation'
  AND relation = 'test_prepared1'::regclass;
    relation     | locktype |        mode         
-----------------+----------+---------------------
 test_prepared_1 | relation | RowExclusiveLock
 test_prepared_1 | relation | AccessExclusiveLock
(2 rows)

-- The insert should show the newly altered column but not the DDL.
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
                                  data                                   
-------------------------------------------------------------------------
 BEGIN
 table public.test_prepared1: INSERT: id[integer]:4 data[text]:'frakbar'
 PREPARE TRANSACTION 'test_prepared#3'
(3 rows)

-- Test that we decode correctly while an uncommitted prepared xact
-- with ddl exists.
--
-- Use a separate table for the concurrent transaction because the lock from
-- the ALTER will stop us inserting into the other one.
--
INSERT INTO test_prepared2 VALUES (5);
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
                        data                        
----------------------------------------------------
 BEGIN
 table public.test_prepared2: INSERT: id[integer]:5
 COMMIT
(3 rows)

COMMIT PREPARED 'test_prepared#3';
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
               data                
-----------------------------------
 COMMIT PREPARED 'test_prepared#3'
(1 row)

-- make sure stuff still works
INSERT INTO test_prepared1 VALUES (6);
INSERT INTO test_prepared2 VALUES (7);
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
                                data                                
--------------------------------------------------------------------
 BEGIN
 table public.test_prepared1: INSERT: id[integer]:6 data[text]:null
 COMMIT
 BEGIN
 table public.test_prepared2: INSERT: id[integer]:7
 COMMIT
(6 rows)

-- Check 'CLUSTER' (as operation that hold exclusive lock) doesn't block
-- logical decoding.
BEGIN;
INSERT INTO test_prepared1 VALUES (8, 'othercol');
CLUSTER test_prepared1 USING test_prepared1_pkey;
INSERT INTO test_prepared1 VALUES (9, 'othercol2');
PREPARE TRANSACTION 'test_prepared_lock';
SELECT 'test_prepared1' AS relation, locktype, mode
FROM pg_locks
WHERE locktype = 'relation'
  AND relation = 'test_prepared1'::regclass;
    relation    | locktype |        mode         
----------------+----------+---------------------
 test_prepared1 | relation | RowExclusiveLock
 test_prepared1 | relation | ShareLock
 test_prepared1 | relation | AccessExclusiveLock
(3 rows)

-- The above CLUSTER command shouldn't cause a timeout on 2pc decoding.
\set env_timeout ''
\getenv env_timeout PG_TEST_TIMEOUT_DEFAULT
SELECT COALESCE(NULLIF(:'env_timeout', ''), '180') || 's' AS timeout \gset
SET statement_timeout = :'timeout';
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
                                   data                                    
---------------------------------------------------------------------------
 BEGIN
 table public.test_prepared1: INSERT: id[integer]:8 data[text]:'othercol'
 table public.test_prepared1: INSERT: id[integer]:9 data[text]:'othercol2'
 PREPARE TRANSACTION 'test_prepared_lock'
(4 rows)

RESET statement_timeout;
COMMIT PREPARED 'test_prepared_lock';
-- consume the commit
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
                 data                 
--------------------------------------
 COMMIT PREPARED 'test_prepared_lock'
(1 row)

-- Test savepoints and sub-xacts. Creating savepoints will create
-- sub-xacts implicitly.
BEGIN;
CREATE TABLE test_prepared_savepoint (a int);
INSERT INTO test_prepared_savepoint VALUES (1);
SAVEPOINT test_savepoint;
INSERT INTO test_prepared_savepoint VALUES (2);
ROLLBACK TO SAVEPOINT test_savepoint;
PREPARE TRANSACTION 'test_prepared_savepoint';
-- should show only 1, not 2
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
                            data                            
------------------------------------------------------------
 BEGIN
 table public.test_prepared_savepoint: INSERT: a[integer]:1
 PREPARE TRANSACTION 'test_prepared_savepoint'
(3 rows)

COMMIT PREPARED 'test_prepared_savepoint';
-- consume the commit
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
                   data                    
-------------------------------------------
 COMMIT PREPARED 'test_prepared_savepoint'
(1 row)

-- Test that a GID containing "_nodecode" gets decoded at commit prepared time.
BEGIN;
INSERT INTO test_prepared1 VALUES (20);
PREPARE TRANSACTION 'test_prepared_nodecode';
-- should show nothing
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
 data 
------
(0 rows)

COMMIT PREPARED 'test_prepared_nodecode';
-- should be decoded now
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
                                data                                 
---------------------------------------------------------------------
 BEGIN
 table public.test_prepared1: INSERT: id[integer]:20 data[text]:null
 COMMIT
(3 rows)

-- Test that accessing a TOAST table is permitted during the decoding of a
-- prepared transaction.
-- Create a table with a column that uses a TOASTed default value.
-- (temporarily hide query, to avoid the long CREATE TABLE stmt)
\set ECHO none
BEGIN;
INSERT INTO test_tab VALUES('test');
PREPARE TRANSACTION 'test_toast_table_access';
SELECT count(*) FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1', 'stream-changes', '1');
 count 
-------
     3
(1 row)

COMMIT PREPARED 'test_toast_table_access';
-- consume commit prepared
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1', 'stream-changes', '1');
                   data                    
-------------------------------------------
 COMMIT PREPARED 'test_toast_table_access'
(1 row)

-- Test that an empty prepared transaction should not be decoded, whether it
-- is committed or rolled back.
BEGIN;
SELECT * FROM test_prepared1 WHERE id = 1 FOR SHARE;
 id | data 
----+------
  1 | 
(1 row)

PREPARE TRANSACTION 'test_empty_transaction';
COMMIT PREPARED 'test_empty_transaction';
BEGIN;
SELECT * FROM test_prepared1 WHERE id = 1 FOR SHARE;
 id | data 
----+------
  1 | 
(1 row)

PREPARE TRANSACTION 'test_empty_transaction';
ROLLBACK PREPARED 'test_empty_transaction';
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
 data 
------
(0 rows)

-- Test 8:
-- cleanup and make sure results are also empty
DROP TABLE test_prepared1;
DROP TABLE test_prepared2;
DROP TABLE test_prepared_savepoint;
DROP TABLE test_tab;
-- show results. There should be nothing to show
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
 data 
------
(0 rows)

SELECT pg_drop_replication_slot('regression_slot');
 pg_drop_replication_slot 
--------------------------
 
(1 row)