From b8fb29126fdc6083bf2d020fc5e55f3cb9ad050d Mon Sep 17 00:00:00 2001 From: houzj Date: Thu, 18 Feb 2021 11:17:35 +0800 Subject: [PATCH] reloption parallel parallel_dml_enabled test and doc Test and documentation updates for reloption parallel_dml_enabled. --- doc/src/sgml/ref/alter_table.sgml | 2 +- doc/src/sgml/ref/create_table.sgml | 27 +++++++++++++++++ src/test/regress/expected/insert_parallel.out | 42 ++++++++++++++++++++++++--- src/test/regress/sql/insert_parallel.sql | 34 +++++++++++++++++++--- 4 files changed, 96 insertions(+), 9 deletions(-) diff --git a/doc/src/sgml/ref/alter_table.sgml b/doc/src/sgml/ref/alter_table.sgml index c25ef5a..ecb0470 100644 --- a/doc/src/sgml/ref/alter_table.sgml +++ b/doc/src/sgml/ref/alter_table.sgml @@ -722,7 +722,7 @@ WITH ( MODULUS numeric_literal, REM SHARE UPDATE EXCLUSIVE lock will be taken for fillfactor, toast and autovacuum storage parameters, as well as the - planner parameter parallel_workers. + planner parameter parallel_workers and parallel_dml_enabled. diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml index 569f4c9..f402174 100644 --- a/doc/src/sgml/ref/create_table.sgml +++ b/doc/src/sgml/ref/create_table.sgml @@ -1408,6 +1408,33 @@ WITH ( MODULUS numeric_literal, REM + + parallel_dml_enabled (boolean) + + parallel_dml_enabled storage parameter + + + + + Enables or disables the query planner's use of parallel DML for + this table. When enabled (and provided that + is also true), + the planner performs additional parallel-safety checks on the table's + attributes and indexes, in order to determine if it's safe to use a + parallel plan for table-modification. The default is + true. + In cases such as when the table has a large number of partitions, and + particularly also when that table uses a parallel-unsafe feature that + prevents parallelism, the overhead of these checks may become prohibitively + high. To address this potential overhead in these cases, this option can be + used to disable the use of parallel DML for this table. + Note that if the target table of the parallel DML is partitioned, the + parallel_dml_enabled option values of the partitions are + ignored. + + + + autovacuum_enabled, toast.autovacuum_enabled (boolean) diff --git a/src/test/regress/expected/insert_parallel.out b/src/test/regress/expected/insert_parallel.out index 73330ef..997d8b5 100644 --- a/src/test/regress/expected/insert_parallel.out +++ b/src/test/regress/expected/insert_parallel.out @@ -70,13 +70,13 @@ set max_parallel_workers_per_gather=4; create table para_insert_p1 ( unique1 int4 PRIMARY KEY, stringu1 name -); +) with (parallel_dml_enabled = off); create table para_insert_f1 ( unique1 int4 REFERENCES para_insert_p1(unique1), stringu1 name ); -- --- Test INSERT with underlying query when enable_parallel_dml=off. +-- Test INSERT with underlying query when enable_parallel_dml=off and reloption.parallel_dml_enabled=off. -- (should create plan with serial INSERT + SELECT) -- explain(costs off) insert into para_insert_p1 select unique1, stringu1 from tenk1; @@ -87,10 +87,25 @@ explain(costs off) insert into para_insert_p1 select unique1, stringu1 from tenk (2 rows) -- --- Enable parallel dml +-- Enable guc option enable_parallel_dml -- set enable_parallel_dml = on; -- +-- Test INSERT with underlying query when enable_parallel_dml=on and reloption.parallel_dml_enabled=off. +-- (should create plan with serial INSERT + SELECT) +-- +explain(costs off) insert into para_insert_p1 select unique1, stringu1 from tenk1; + QUERY PLAN +-------------------------- + Insert on para_insert_p1 + -> Seq Scan on tenk1 +(2 rows) + +-- +-- Enable reloption parallel_dml_enabled +-- +alter table para_insert_p1 set (parallel_dml_enabled = on); +-- -- Test INSERT with underlying query. -- (should create plan with parallel INSERT+SELECT, Gather parent node) -- @@ -868,9 +883,28 @@ truncate testdef; -- -- Test INSERT into partition with underlying query. -- -create table parttable1 (a int, b name) partition by range (a); +create table parttable1 (a int, b name) partition by range (a) with (parallel_dml_enabled=off); create table parttable1_1 partition of parttable1 for values from (0) to (5000); create table parttable1_2 partition of parttable1 for values from (5000) to (10000); +-- +-- Test INSERT into partition when reloption.parallel_dml_enabled=off +-- (should not create a parallel plan) +-- +explain (costs off) insert into parttable1 select unique1,stringu1 from tenk1; + QUERY PLAN +------------------------- + Insert on parttable1 + -> Seq Scan on tenk1 +(2 rows) + +-- +-- Enable reloption parallel_dml_enabled +-- +alter table parttable1 set (parallel_dml_enabled = on); +-- +-- Test INSERT into partition when reloption.parallel_dml_enabled=off +-- (should create a parallel plan) +-- explain (costs off) insert into parttable1 select unique1,stringu1 from tenk1; QUERY PLAN ---------------------------------------- diff --git a/src/test/regress/sql/insert_parallel.sql b/src/test/regress/sql/insert_parallel.sql index eba30d2..8cb439b 100644 --- a/src/test/regress/sql/insert_parallel.sql +++ b/src/test/regress/sql/insert_parallel.sql @@ -87,7 +87,7 @@ set max_parallel_workers_per_gather=4; create table para_insert_p1 ( unique1 int4 PRIMARY KEY, stringu1 name -); +) with (parallel_dml_enabled = off); create table para_insert_f1 ( unique1 int4 REFERENCES para_insert_p1(unique1), @@ -95,17 +95,28 @@ create table para_insert_f1 ( ); -- --- Test INSERT with underlying query when enable_parallel_dml=off. +-- Test INSERT with underlying query when enable_parallel_dml=off and reloption.parallel_dml_enabled=off. -- (should create plan with serial INSERT + SELECT) -- explain(costs off) insert into para_insert_p1 select unique1, stringu1 from tenk1; -- --- Enable parallel dml +-- Enable guc option enable_parallel_dml -- set enable_parallel_dml = on; -- +-- Test INSERT with underlying query when enable_parallel_dml=on and reloption.parallel_dml_enabled=off. +-- (should create plan with serial INSERT + SELECT) +-- +explain(costs off) insert into para_insert_p1 select unique1, stringu1 from tenk1; + +-- +-- Enable reloption parallel_dml_enabled +-- +alter table para_insert_p1 set (parallel_dml_enabled = on); + +-- -- Test INSERT with underlying query. -- (should create plan with parallel INSERT+SELECT, Gather parent node) -- @@ -359,10 +370,25 @@ truncate testdef; -- -- Test INSERT into partition with underlying query. -- -create table parttable1 (a int, b name) partition by range (a); +create table parttable1 (a int, b name) partition by range (a) with (parallel_dml_enabled=off); create table parttable1_1 partition of parttable1 for values from (0) to (5000); create table parttable1_2 partition of parttable1 for values from (5000) to (10000); +-- +-- Test INSERT into partition when reloption.parallel_dml_enabled=off +-- (should not create a parallel plan) +-- +explain (costs off) insert into parttable1 select unique1,stringu1 from tenk1; + +-- +-- Enable reloption parallel_dml_enabled +-- +alter table parttable1 set (parallel_dml_enabled = on); + +-- +-- Test INSERT into partition when reloption.parallel_dml_enabled=on +-- (should create a parallel plan) +-- explain (costs off) insert into parttable1 select unique1,stringu1 from tenk1; insert into parttable1 select unique1,stringu1 from tenk1; select count(*) from parttable1_1; -- 2.7.2.windows.1