src/test/regress/expected/write_parallel.out - master - githubmirror/postgres

src/test/regress/expected/write_parallel.out
80 строк3 KB
Thomas Munro
Enable parallelism in REFRESH MATERIALIZED VIEW.
17 мар 2021, 05:04
17 мар 2021, 05:049e7ccd9
--
-- PARALLEL
--
begin;
-- encourage use of parallel plans
set parallel_setup_cost=0;
set parallel_tuple_cost=0;
set min_parallel_table_scan_size=0;
set max_parallel_workers_per_gather=4;
--
-- Test write operations that has an underlying query that is eligible
-- for parallel plans
--
explain (costs off) create table parallel_write as
    select length(stringu1) from tenk1 group by length(stringu1);
                    QUERY PLAN                     
---------------------------------------------------
 Finalize HashAggregate
   Group Key: (length((stringu1)::text))
   ->  Gather
         Workers Planned: 4
         ->  Partial HashAggregate
               Group Key: length((stringu1)::text)
               ->  Parallel Seq Scan on tenk1
(7 rows)

create table parallel_write as
    select length(stringu1) from tenk1 group by length(stringu1);
drop table parallel_write;
explain (costs off) select length(stringu1) into parallel_write
    from tenk1 group by length(stringu1);
                    QUERY PLAN                     
---------------------------------------------------
 Finalize HashAggregate
   Group Key: (length((stringu1)::text))
   ->  Gather
         Workers Planned: 4
         ->  Partial HashAggregate
               Group Key: length((stringu1)::text)
               ->  Parallel Seq Scan on tenk1
(7 rows)

select length(stringu1) into parallel_write
    from tenk1 group by length(stringu1);
drop table parallel_write;
explain (costs off) create materialized view parallel_mat_view as
    select length(stringu1) from tenk1 group by length(stringu1);
                    QUERY PLAN                     
---------------------------------------------------
 Finalize HashAggregate
   Group Key: (length((stringu1)::text))
   ->  Gather
         Workers Planned: 4
         ->  Partial HashAggregate
               Group Key: length((stringu1)::text)
               ->  Parallel Seq Scan on tenk1
(7 rows)

create materialized view parallel_mat_view as
    select length(stringu1) from tenk1 group by length(stringu1);
create unique index on parallel_mat_view(length);
refresh materialized view parallel_mat_view;
refresh materialized view concurrently parallel_mat_view;
drop materialized view parallel_mat_view;
prepare prep_stmt as select length(stringu1) from tenk1 group by length(stringu1);
explain (costs off) create table parallel_write as execute prep_stmt;
                    QUERY PLAN                     
---------------------------------------------------
 Finalize HashAggregate
   Group Key: (length((stringu1)::text))
   ->  Gather
         Workers Planned: 4
         ->  Partial HashAggregate
               Group Key: length((stringu1)::text)
               ->  Parallel Seq Scan on tenk1
(7 rows)

create table parallel_write as execute prep_stmt;
drop table parallel_write;
rollback;