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--
-- 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;
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