From 3c0c827dff2c3e2dfab51daa72c1d226c484ab13 Mon Sep 17 00:00:00 2001 From: David Rowley Date: Thu, 30 Jul 2026 14:17:04 +1200 Subject: [PATCH v1] Fix issue with RANGE partition pruning being too aggressive Partition pruning for RANGE-partitioned tables could mistakenly prune the DEFAULT partition in some cases when it was not valid to do so. This could lead to result sets not containing rows that should have matched the query's WHERE clause. The only known cases where this could happen is when combining pruning steps from an IS NOT NULL clause with other steps that matched to the DEFAULT partition. This could occur due to RANGE partitioned tables having two separate internal representations for marking if the DEFAULT partition should be scanned or not. The IS NOT NULL steps would mark the "scan_default" boolean, but other steps would mark a bound_offset bit, which would ultimately translate into also scanning the default partition. This could all fail after multiple steps were combined with a combine intersect operator, as it will intersect the bound_offset bits and only set scan_default if all pruning steps have that flag set. Here, we fix this by having the IS NOT NULL pruning result mark the bound_offsets so that it uses both representations to mark that the DEFAULT partition must be scanned. Reported-by: Jacob Brazeal Discussion: https://postgr.es/m/CA+COZaDXrfTaBjLE=Z79MTaH6Xun1V4PeKxLvCNv8mXS8wn0rw@mail.gmail.comOA --- src/backend/partitioning/partprune.c | 10 ++-------- src/test/regress/expected/partition_prune.out | 12 ++++++++++++ src/test/regress/sql/partition_prune.sql | 1 + 3 files changed, 15 insertions(+), 8 deletions(-) diff --git a/src/backend/partitioning/partprune.c b/src/backend/partitioning/partprune.c index e7c318bbcac..afe57ac297d 100644 --- a/src/backend/partitioning/partprune.c +++ b/src/backend/partitioning/partprune.c @@ -3031,15 +3031,9 @@ get_matching_range_bounds(PartitionPruneContext *context, */ if (nvalues == 0) { - /* ignore key space not covered by any partitions */ - if (partindices[minoff] < 0) - minoff++; - if (partindices[maxoff] < 0) - maxoff--; - result->scan_default = partition_bound_has_default(boundinfo); - Assert(partindices[minoff] >= 0 && - partindices[maxoff] >= 0); + Assert(partindices[minoff] >= -1 && + partindices[maxoff] >= -1); result->bound_offsets = bms_add_range(NULL, minoff, maxoff); return result; diff --git a/src/test/regress/expected/partition_prune.out b/src/test/regress/expected/partition_prune.out index 849049f9c51..573bd67e8a4 100644 --- a/src/test/regress/expected/partition_prune.out +++ b/src/test/regress/expected/partition_prune.out @@ -569,6 +569,18 @@ explain (costs off) select * from rlp where a = 1 or b = 'ab'; Filter: ((a = 1) OR ((b)::text = 'ab'::text)) (25 rows) +explain (costs off) select * from rlp where a is not null and a in(9,20,30); + QUERY PLAN +-------------------------------------------------------------------------- + Append + -> Seq Scan on rlp2 rlp_1 + Filter: ((a IS NOT NULL) AND (a = ANY ('{9,20,30}'::integer[]))) + -> Seq Scan on rlp4_1 rlp_2 + Filter: ((a IS NOT NULL) AND (a = ANY ('{9,20,30}'::integer[]))) + -> Seq Scan on rlp_default_30 rlp_3 + Filter: ((a IS NOT NULL) AND (a = ANY ('{9,20,30}'::integer[]))) +(7 rows) + explain (costs off) select * from rlp where a > 20 and a < 27; QUERY PLAN ----------------------------------------- diff --git a/src/test/regress/sql/partition_prune.sql b/src/test/regress/sql/partition_prune.sql index 359a9208056..9a543ccd1ac 100644 --- a/src/test/regress/sql/partition_prune.sql +++ b/src/test/regress/sql/partition_prune.sql @@ -102,6 +102,7 @@ explain (costs off) select * from rlp where a = 30; /* only default is scanned * explain (costs off) select * from rlp where a <= 31; explain (costs off) select * from rlp where a = 1 or a = 7; explain (costs off) select * from rlp where a = 1 or b = 'ab'; +explain (costs off) select * from rlp where a is not null and a in(9,20,30); explain (costs off) select * from rlp where a > 20 and a < 27; explain (costs off) select * from rlp where a = 29; -- 2.53.0