From 5946426e7eb7d5fb77b3562f23fc287af5f65eb2 Mon Sep 17 00:00:00 2001 From: Amit Langote Date: Thu, 18 Sep 2025 10:09:47 +0900 Subject: [PATCH v2] Fix EPQ crash from missing partition pruning state in EState Commit bb3ec16e14 moved partition pruning metadata into PlannedStmt. At executor startup this metadata is used to initialize the EState fields es_part_prune_infos, es_part_prune_states, and es_part_prune_results. EvalPlanQualStart() failed to copy those fields into the child EState, causing NULL dereference when Append ran partition pruning during a recheck. This can occur with DELETE or UPDATE on partitioned tables that use runtime pruning, e.g. with generic plans. Fix by copying all partition pruning state into the EPQ estate. Add an isolation test that reproduces the crash with concurrent UPDATE and DELETE on a partitioned table, where the DELETE session hits the crash during its EPQ recheck after the UPDATE commits. Bug: #19056 Reported-by: Fei Changhong Diagnozed-by: Fei Changhong Author: David Rowley Co-authored-by: Amit Langote Discussion: https://postgr.es/m/19056-a677cef9b54d76a0%40postgresql.org --- src/backend/executor/execMain.c | 9 +++++++++ .../isolation/expected/eval-plan-qual.out | 18 +++++++++++++++++- src/test/isolation/specs/eval-plan-qual.spec | 19 +++++++++++++++++++ 3 files changed, 45 insertions(+), 1 deletion(-) diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c index ff12e2e1364..831c55ce787 100644 --- a/src/backend/executor/execMain.c +++ b/src/backend/executor/execMain.c @@ -3084,6 +3084,15 @@ EvalPlanQualStart(EPQState *epqstate, Plan *planTree) */ rcestate->es_unpruned_relids = parentestate->es_unpruned_relids; + /* + * Also make the PartitionPruneInfo and the results of pruning available. + * These need to match exactly so that we initialize all the same Append + * and MergeAppend subplans as the parent did. + */ + rcestate->es_part_prune_infos = parentestate->es_part_prune_infos; + rcestate->es_part_prune_states = parentestate->es_part_prune_states; + rcestate->es_part_prune_results = parentestate->es_part_prune_results; + /* * Initialize private state information for each SubPlan. We must do this * before running ExecInitNode on the main query tree, since diff --git a/src/test/isolation/expected/eval-plan-qual.out b/src/test/isolation/expected/eval-plan-qual.out index 032d4208d51..33c3f7c0ed4 100644 --- a/src/test/isolation/expected/eval-plan-qual.out +++ b/src/test/isolation/expected/eval-plan-qual.out @@ -1,4 +1,4 @@ -Parsed test spec with 3 sessions +Parsed test spec with 5 sessions starting permutation: wx1 wx2 c1 c2 read step wx1: UPDATE accounts SET balance = balance - 200 WHERE accountid = 'checking' RETURNING balance; @@ -1363,3 +1363,19 @@ step sysmerge2: step c1: COMMIT; step sysmerge2: <... completed> step c2: COMMIT; + +starting permutation: s1pp1 s1pp2 s2pp1 s2pp2 s2pp3 s1pp3 s2pp4 s2pp5 +step s1pp1: BEGIN; +step s1pp2: UPDATE another_parttbl SET b = b + 1 WHERE a = 1; +step s2pp1: SET plan_cache_mode TO force_generic_plan; +step s2pp2: PREPARE epd AS DELETE FROM another_parttbl WHERE a = $1; +step s2pp3: EXECUTE epd(1); +step s1pp3: COMMIT; +step s2pp3: <... completed> +step s2pp4: SELECT count(*) FROM another_parttbl; +count +----- + 0 +(1 row) + +step s2pp5: DEALLOCATE epd; diff --git a/src/test/isolation/specs/eval-plan-qual.spec b/src/test/isolation/specs/eval-plan-qual.spec index 07307e623e4..0b973778715 100644 --- a/src/test/isolation/specs/eval-plan-qual.spec +++ b/src/test/isolation/specs/eval-plan-qual.spec @@ -334,6 +334,22 @@ step multireadwcte { teardown { COMMIT; } +# Test that EState.es_part_prune_infos is properly set in EvalPlanQualStart() +# Bug #19056 +session s4 + +step s1pp1 { BEGIN; } +step s1pp2 { UPDATE another_parttbl SET b = b + 1 WHERE a = 1; } +step s1pp3 { COMMIT; } + +session s5 + +step s2pp1 { SET plan_cache_mode TO force_generic_plan; } +step s2pp2 { PREPARE epd AS DELETE FROM another_parttbl WHERE a = $1; } +step s2pp3 { EXECUTE epd(1); } +step s2pp4 { SELECT count(*) FROM another_parttbl; } +step s2pp5 { DEALLOCATE epd;} + # test that normal update follows update chains, and reverifies quals permutation wx1 wx2 c1 c2 read permutation wy1 wy2 c1 c2 read @@ -401,3 +417,6 @@ permutation simplepartupdate_noroute complexpartupdate_doesnt_route c1 c2 read_p permutation sys1 sysupd2 c1 c2 permutation sys1 sysmerge2 c1 c2 + +# EState.es_part_prune_infos bug #19056 +permutation s1pp1 s1pp2 s2pp1 s2pp2 s2pp3 s1pp3 s2pp4 s2pp5 -- 2.43.0