From f2e20542dac2e25bc37440e66fd2769c29f2836b Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Thu, 11 Dec 2014 21:02:28 -0500 Subject: [PATCH] Fix planning of SELECT FOR UPDATE on child table with partial index. Ordinarily we can omit checking of a WHERE condition that matches a partial index's condition, when we are using an indexscan on that partial index. However, in SELECT FOR UPDATE we must include the "redundant" filter condition in the plan so that it gets checked properly in an EvalPlanQual recheck. The planner got this mostly right, but improperly omitted the filter condition if the index in question was on an inheritance child table. In READ COMMITTED mode, this could result in incorrectly returning just-updated rows that no longer satisfy the filter condition. The cause of the error is using get_parse_rowmark() when get_plan_rowmark() is what should be used during planning. In 9.3 and up, also fix the same mistake in contrib/postgres_fdw. It's currently harmless there (for lack of inheritance support) but wrong is wrong, and the incorrect code might get copied to someplace where it's more significant. Report and fix by Kyotaro Horiguchi. Back-patch to all supported branches. --- contrib/postgres_fdw/postgres_fdw.c | 17 ++++++++++------- src/backend/optimizer/plan/createplan.c | 3 ++- 2 files changed, 12 insertions(+), 8 deletions(-) diff --git a/contrib/postgres_fdw/postgres_fdw.c b/contrib/postgres_fdw/postgres_fdw.c index 7dd43a9937..c3a683715a 100644 --- a/contrib/postgres_fdw/postgres_fdw.c +++ b/contrib/postgres_fdw/postgres_fdw.c @@ -817,7 +817,7 @@ postgresGetForeignPlan(PlannerInfo *root, } else { - RowMarkClause *rc = get_parse_rowmark(root->parse, baserel->relid); + PlanRowMark *rc = get_plan_rowmark(root->rowMarks, baserel->relid); if (rc) { @@ -830,15 +830,18 @@ postgresGetForeignPlan(PlannerInfo *root, * complete information about, and (b) it wouldn't work anyway on * older remote servers. Likewise, we don't worry about NOWAIT. */ - switch (rc->strength) + switch (rc->markType) { - case LCS_FORKEYSHARE: - case LCS_FORSHARE: + case ROW_MARK_EXCLUSIVE: + case ROW_MARK_NOKEYEXCLUSIVE: + appendStringInfoString(&sql, " FOR UPDATE"); + break; + case ROW_MARK_SHARE: + case ROW_MARK_KEYSHARE: appendStringInfoString(&sql, " FOR SHARE"); break; - case LCS_FORNOKEYUPDATE: - case LCS_FORUPDATE: - appendStringInfoString(&sql, " FOR UPDATE"); + default: + /* nothing needed */ break; } } diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c index b135f18355..e8b97c03a9 100644 --- a/src/backend/optimizer/plan/createplan.c +++ b/src/backend/optimizer/plan/createplan.c @@ -34,6 +34,7 @@ #include "optimizer/planmain.h" #include "optimizer/planner.h" #include "optimizer/predtest.h" +#include "optimizer/prep.h" #include "optimizer/restrictinfo.h" #include "optimizer/subselect.h" #include "optimizer/tlist.h" @@ -1219,7 +1220,7 @@ create_indexscan_plan(PlannerInfo *root, if (best_path->indexinfo->indpred) { if (baserelid != root->parse->resultRelation && - get_parse_rowmark(root->parse, baserelid) == NULL) + get_plan_rowmark(root->rowMarks, baserelid) == NULL) if (predicate_implied_by(clausel, best_path->indexinfo->indpred)) continue; /* implied by index predicate */ -- 2.40.0