Horton

Fix EvalPlanQual rechecking during MERGE.

Dean Rasheed <dean.a.rasheed@gmail.com>

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Commit: 1d5caec221d85b8950a1ee3d8bb6fad262549ea6
Author: Dean Rasheed <dean.a.rasheed@gmail.com>
Date: 2023-09-30T09:52:21Z
Releases: 17.0 
Fix EvalPlanQual rechecking during MERGE.

Under some circumstances, concurrent MERGE operations could lead to
inconsistent results, that varied according the plan chosen. This was
caused by a lack of rowmarks on the source relation, which meant that
EvalPlanQual rechecking was not guaranteed to return the same source
tuples when re-running the join query.

Fix by ensuring that preprocess_rowmarks() sets up PlanRowMarks for
all non-target relations used in MERGE, in the same way that it does
for UPDATE and DELETE.

Per bug #18103. Back-patch to v15, where MERGE was introduced.

Dean Rasheed, reviewed by Richard Guo.

Discussion: https://postgr.es/m/18103-c4386baab8e355e3%40postgresql.org

Files

PathChange+/−
src/backend/executor/nodeModifyTable.c modified +3 −3
src/backend/executor/README modified +6 −6
src/backend/optimizer/plan/planner.c modified +3 −2
src/include/nodes/execnodes.h modified +2 −2
src/include/nodes/plannodes.h modified +2 −2
src/test/isolation/expected/merge-join.out added +148 −0
src/test/isolation/isolation_schedule modified +1 −0
src/test/isolation/specs/merge-join.spec added +45 −0
src/test/regress/expected/merge.out modified +4 −4
src/test/regress/expected/with.out modified +23 −19

Discussion