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Expand run-time partition pruning to work with MergeAppend

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This expands the support for the run-time partition pruning which was added
for Append in 499be013de to also allow unneeded subnodes of a MergeAppend
to be removed.

Author: David Rowley
Discussion: https://www.postgresql.org/message-id/CAKJS1f_F_V8D7Wu-HVdnH7zCUxhoGK8XhLLtd%3DCu85qDZzXrgg%40mail.gmail.com
This commit is contained in:
Heikki Linnakangas
2018-07-19 13:49:43 +03:00
parent b33ef397a1
commit 5220bb7533
11 changed files with 356 additions and 35 deletions
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137
src/test/regress/expected/partition_prune.out
View File

@ -2824,6 +2824,143 @@ select * from boolp where a = (select value from boolvalues where not value);
(9 rows)
drop table boolp;
--
-- Test run-time pruning of MergeAppend subnodes
--
set enable_seqscan = off;
set enable_sort = off;
create table ma_test (a int) partition by range (a);
create table ma_test_p1 partition of ma_test for values from (0) to (10);
create table ma_test_p2 partition of ma_test for values from (10) to (20);
create table ma_test_p3 partition of ma_test for values from (20) to (30);
insert into ma_test select x from generate_series(0,29) t(x);
create index on ma_test (a);
analyze ma_test;
prepare mt_q1 (int) as select * from ma_test where a >= $1 and a % 10 = 5 order by a;
-- Execute query 5 times to allow choose_custom_plan
-- to start considering a generic plan.
execute mt_q1(0);
a
----
5
15
25
(3 rows)
execute mt_q1(0);
a
----
5
15
25
(3 rows)
execute mt_q1(0);
a
----
5
15
25
(3 rows)
execute mt_q1(0);
a
----
5
15
25
(3 rows)
execute mt_q1(0);
a
----
5
15
25
(3 rows)
explain (analyze, costs off, summary off, timing off) execute mt_q1(15);
QUERY PLAN
-------------------------------------------------------------------------------
Merge Append (actual rows=2 loops=1)
Sort Key: ma_test_p2.a
Subplans Removed: 1
-> Index Scan using ma_test_p2_a_idx on ma_test_p2 (actual rows=1 loops=1)
Index Cond: (a >= $1)
Filter: ((a % 10) = 5)
Rows Removed by Filter: 4
-> Index Scan using ma_test_p3_a_idx on ma_test_p3 (actual rows=1 loops=1)
Index Cond: (a >= $1)
Filter: ((a % 10) = 5)
Rows Removed by Filter: 9
(11 rows)
execute mt_q1(15);
a
----
15
25
(2 rows)
explain (analyze, costs off, summary off, timing off) execute mt_q1(25);
QUERY PLAN
-------------------------------------------------------------------------------
Merge Append (actual rows=1 loops=1)
Sort Key: ma_test_p3.a
Subplans Removed: 2
-> Index Scan using ma_test_p3_a_idx on ma_test_p3 (actual rows=1 loops=1)
Index Cond: (a >= $1)
Filter: ((a % 10) = 5)
Rows Removed by Filter: 4
(7 rows)
execute mt_q1(25);
a
----
25
(1 row)
-- Ensure MergeAppend behaves correctly when no subplans match
explain (analyze, costs off, summary off, timing off) execute mt_q1(35);
QUERY PLAN
------------------------------------------------------------------------
Merge Append (actual rows=0 loops=1)
Sort Key: ma_test_p1.a
Subplans Removed: 2
-> Index Scan using ma_test_p1_a_idx on ma_test_p1 (never executed)
Index Cond: (a >= $1)
Filter: ((a % 10) = 5)
(6 rows)
execute mt_q1(35);
a
---
(0 rows)
deallocate mt_q1;
-- ensure initplan params properly prune partitions
explain (analyze, costs off, summary off, timing off) select * from ma_test where a >= (select min(a) from ma_test_p2) order by a;
QUERY PLAN
------------------------------------------------------------------------------------------------------------
Merge Append (actual rows=20 loops=1)
Sort Key: ma_test_p1.a
InitPlan 2 (returns $1)
-> Result (actual rows=1 loops=1)
InitPlan 1 (returns $0)
-> Limit (actual rows=1 loops=1)
-> Index Scan using ma_test_p2_a_idx on ma_test_p2 ma_test_p2_1 (actual rows=1 loops=1)
Index Cond: (a IS NOT NULL)
-> Index Scan using ma_test_p1_a_idx on ma_test_p1 (never executed)
Index Cond: (a >= $1)
-> Index Scan using ma_test_p2_a_idx on ma_test_p2 (actual rows=10 loops=1)
Index Cond: (a >= $1)
-> Index Scan using ma_test_p3_a_idx on ma_test_p3 (actual rows=10 loops=1)
Index Cond: (a >= $1)
(14 rows)
reset enable_seqscan;
reset enable_sort;
drop table ma_test;
reset enable_indexonlyscan;
--
-- check that pruning works properly when the partition key is of a

41
src/test/regress/sql/partition_prune.sql
View File

@ -714,6 +714,47 @@ select * from boolp where a = (select value from boolvalues where not value);
drop table boolp;
--
-- Test run-time pruning of MergeAppend subnodes
--
set enable_seqscan = off;
set enable_sort = off;
create table ma_test (a int) partition by range (a);
create table ma_test_p1 partition of ma_test for values from (0) to (10);
create table ma_test_p2 partition of ma_test for values from (10) to (20);
create table ma_test_p3 partition of ma_test for values from (20) to (30);
insert into ma_test select x from generate_series(0,29) t(x);
create index on ma_test (a);
analyze ma_test;
prepare mt_q1 (int) as select * from ma_test where a >= $1 and a % 10 = 5 order by a;
-- Execute query 5 times to allow choose_custom_plan
-- to start considering a generic plan.
execute mt_q1(0);
execute mt_q1(0);
execute mt_q1(0);
execute mt_q1(0);
execute mt_q1(0);
explain (analyze, costs off, summary off, timing off) execute mt_q1(15);
execute mt_q1(15);
explain (analyze, costs off, summary off, timing off) execute mt_q1(25);
execute mt_q1(25);
-- Ensure MergeAppend behaves correctly when no subplans match
explain (analyze, costs off, summary off, timing off) execute mt_q1(35);
execute mt_q1(35);
deallocate mt_q1;
-- ensure initplan params properly prune partitions
explain (analyze, costs off, summary off, timing off) select * from ma_test where a >= (select min(a) from ma_test_p2) order by a;
reset enable_seqscan;
reset enable_sort;
drop table ma_test;
reset enable_indexonlyscan;
--