From d9e46dfb78abf4d3be6071b8c4495df9e1bb4706 Mon Sep 17 00:00:00 2001 From: David Rowley Date: Fri, 13 Oct 2023 01:12:31 +1300 Subject: [PATCH] Fix runtime partition pruning for HASH partitioned tables This could only affect HASH partitioned tables with at least 2 partition key columns. If partition pruning was delayed until execution and the query contained an IS NULL qual on one of the partitioned keys, and some subsequent partitioned key was being compared to a non-Const, then this could result in a crash due to the incorrect keyno being used to calculate the stateidx for the expression evaluation code. Here we fix this by properly skipping partitioned keys which have a nullkey set. Effectively, this must be the same as what's going on inside perform_pruning_base_step(). Sergei Glukhov also provided a patch, but that's not what's being used here. Reported-by: Sergei Glukhov Reviewed-by: tender wang, Sergei Glukhov Discussion: https://postgr.es/m/d05b26fa-af54-27e1-f693-6c31590802fa@postgrespro.ru Backpatch-through: 11, where runtime partition pruning was added. --- src/backend/executor/execPartition.c | 53 ++++++++++--------- src/test/regress/expected/partition_prune.out | 22 +++++++- src/test/regress/sql/partition_prune.sql | 21 +++++++- 3 files changed, 69 insertions(+), 27 deletions(-) diff --git a/src/backend/executor/execPartition.c b/src/backend/executor/execPartition.c index eb8a87fd632..f6c34328b85 100644 --- a/src/backend/executor/execPartition.c +++ b/src/backend/executor/execPartition.c @@ -2108,7 +2108,7 @@ InitPartitionPruneContext(PartitionPruneContext *context, foreach(lc, pruning_steps) { PartitionPruneStepOp *step = (PartitionPruneStepOp *) lfirst(lc); - ListCell *lc2; + ListCell *lc2 = list_head(step->exprs); int keyno; /* not needed for other step kinds */ @@ -2117,34 +2117,39 @@ InitPartitionPruneContext(PartitionPruneContext *context, Assert(list_length(step->exprs) <= partnatts); - keyno = 0; - foreach(lc2, step->exprs) + for (keyno = 0; keyno < partnatts; keyno++) { - Expr *expr = (Expr *) lfirst(lc2); + if (bms_is_member(keyno, step->nullkeys)) + continue; - /* not needed for Consts */ - if (!IsA(expr, Const)) + if (lc2 != NULL) { - int stateidx = PruneCxtStateIdx(partnatts, - step->step.step_id, - keyno); + Expr *expr = lfirst(lc2); - /* - * When planstate is NULL, pruning_steps is known not to - * contain any expressions that depend on the parent plan. - * Information of any available EXTERN parameters must be - * passed explicitly in that case, which the caller must have - * made available via econtext. - */ - if (planstate == NULL) - context->exprstates[stateidx] = - ExecInitExprWithParams(expr, - econtext->ecxt_param_list_info); - else - context->exprstates[stateidx] = - ExecInitExpr(expr, context->planstate); + /* not needed for Consts */ + if (!IsA(expr, Const)) + { + int stateidx = PruneCxtStateIdx(partnatts, + step->step.step_id, + keyno); + + /* + * When planstate is NULL, pruning_steps is known not to + * contain any expressions that depend on the parent plan. + * Information of any available EXTERN parameters must be + * passed explicitly in that case, which the caller must + * have made available via econtext. + */ + if (planstate == NULL) + context->exprstates[stateidx] = + ExecInitExprWithParams(expr, + econtext->ecxt_param_list_info); + else + context->exprstates[stateidx] = + ExecInitExpr(expr, context->planstate); + } + lc2 = lnext(step->exprs, lc2); } - keyno++; } } } diff --git a/src/test/regress/expected/partition_prune.out b/src/test/regress/expected/partition_prune.out index c453c3def24..9a4c48c0556 100644 --- a/src/test/regress/expected/partition_prune.out +++ b/src/test/regress/expected/partition_prune.out @@ -1948,7 +1948,6 @@ explain (costs off) select * from hp where a = 1 and b = 'abcde' and One-Time Filter: false (2 rows) -drop table hp; -- -- Test runtime partition pruning -- @@ -2070,6 +2069,27 @@ explain (analyze, costs off, summary off, timing off) execute ab_q3 (2, 2); Filter: ((b >= $1) AND (b <= $2) AND (a < $0)) (10 rows) +-- +-- Test runtime pruning with hash partitioned tables +-- +-- recreate partitions dropped above +create table hp1 partition of hp for values with (modulus 4, remainder 1); +create table hp2 partition of hp for values with (modulus 4, remainder 2); +create table hp3 partition of hp for values with (modulus 4, remainder 3); +-- Ensure we correctly prune unneeded partitions when there is an IS NULL qual +prepare hp_q1 (text) as +select * from hp where a is null and b = $1; +explain (costs off) execute hp_q1('xxx'); + QUERY PLAN +-------------------------------------------- + Append + Subplans Removed: 3 + -> Seq Scan on hp2 hp_1 + Filter: ((a IS NULL) AND (b = $1)) +(4 rows) + +deallocate hp_q1; +drop table hp; -- Test a backwards Append scan create table list_part (a int) partition by list (a); create table list_part1 partition of list_part for values in (1); diff --git a/src/test/regress/sql/partition_prune.sql b/src/test/regress/sql/partition_prune.sql index 9092e61e7ec..7bf3920827f 100644 --- a/src/test/regress/sql/partition_prune.sql +++ b/src/test/regress/sql/partition_prune.sql @@ -384,8 +384,6 @@ drop table hp2; explain (costs off) select * from hp where a = 1 and b = 'abcde' and (c = 2 or c = 3); -drop table hp; - -- -- Test runtime partition pruning -- @@ -436,6 +434,25 @@ select a from ab where b between $1 and $2 and a < (select 3); explain (analyze, costs off, summary off, timing off) execute ab_q3 (2, 2); +-- +-- Test runtime pruning with hash partitioned tables +-- + +-- recreate partitions dropped above +create table hp1 partition of hp for values with (modulus 4, remainder 1); +create table hp2 partition of hp for values with (modulus 4, remainder 2); +create table hp3 partition of hp for values with (modulus 4, remainder 3); + +-- Ensure we correctly prune unneeded partitions when there is an IS NULL qual +prepare hp_q1 (text) as +select * from hp where a is null and b = $1; + +explain (costs off) execute hp_q1('xxx'); + +deallocate hp_q1; + +drop table hp; + -- Test a backwards Append scan create table list_part (a int) partition by list (a); create table list_part1 partition of list_part for values in (1);