diff options
| -rw-r--r-- | src/backend/optimizer/plan/createplan.c | 42 |
1 files changed, 32 insertions, 10 deletions
diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c index d5a39d7aa7b..a5867af9cd2 100644 --- a/src/backend/optimizer/plan/createplan.c +++ b/src/backend/optimizer/plan/createplan.c @@ -10,7 +10,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/optimizer/plan/createplan.c,v 1.202.2.2 2006/01/29 18:55:55 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/optimizer/plan/createplan.c,v 1.202.2.3 2006/04/25 16:54:26 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -816,8 +816,12 @@ create_indexscan_plan(PlannerInfo *root, * are not equal to, but are logically implied by, the index quals; so we * also try a predicate_implied_by() check to see if we can discard quals * that way. (predicate_implied_by assumes its first input contains only - * immutable functions, so we have to check that.) We can also discard - * quals that are implied by a partial index's predicate. + * immutable functions, so we have to check that.) + * + * We can also discard quals that are implied by a partial index's + * predicate, but only in a plain SELECT; when scanning a target relation + * of UPDATE/DELETE/SELECT FOR UPDATE, we must leave such quals in the + * plan so that they'll be properly rechecked by EvalPlanQual testing. * * While at it, we strip off the RestrictInfos to produce a list of plain * expressions. @@ -836,8 +840,14 @@ create_indexscan_plan(PlannerInfo *root, if (predicate_implied_by(clausel, nonlossy_indexquals)) continue; - if (predicate_implied_by(clausel, best_path->indexinfo->indpred)) - continue; + if (best_path->indexinfo->indpred) + { + if (baserelid != root->parse->resultRelation && + !list_member_int(root->parse->rowMarks, baserelid)) + if (predicate_implied_by(clausel, + best_path->indexinfo->indpred)) + continue; + } } qpqual = lappend(qpqual, rinfo->clause); } @@ -920,8 +930,12 @@ create_bitmap_scan_plan(PlannerInfo *root, * but are logically implied by, the index quals; so we also try a * predicate_implied_by() check to see if we can discard quals that way. * (predicate_implied_by assumes its first input contains only immutable - * functions, so we have to check that.) We can also discard quals that - * are implied by a partial index's predicate. + * functions, so we have to check that.) + * + * We can also discard quals that are implied by a partial index's + * predicate, but only in a plain SELECT; when scanning a target relation + * of UPDATE/DELETE/SELECT FOR UPDATE, we must leave such quals in the + * plan so that they'll be properly rechecked by EvalPlanQual testing. * * XXX For the moment, we only consider partial index predicates in the * simple single-index-scan case. Is it worth trying to be smart about @@ -945,8 +959,14 @@ create_bitmap_scan_plan(PlannerInfo *root, { IndexPath *ipath = (IndexPath *) best_path->bitmapqual; - if (predicate_implied_by(clausel, ipath->indexinfo->indpred)) - continue; + if (ipath->indexinfo->indpred) + { + if (baserelid != root->parse->resultRelation && + !list_member_int(root->parse->rowMarks, baserelid)) + if (predicate_implied_by(clausel, + ipath->indexinfo->indpred)) + continue; + } } } qpqual = lappend(qpqual, clause); @@ -1282,7 +1302,9 @@ create_nestloop_plan(PlannerInfo *root, * join quals; failing to prove that doesn't result in an incorrect * plan. It is the right way to proceed because adding more quals to * the stuff we got from the original query would just make it harder - * to detect duplication. + * to detect duplication. (Also, to change this we'd have to be + * wary of UPDATE/DELETE/SELECT FOR UPDATE target relations; see + * notes above about EvalPlanQual.) */ BitmapHeapPath *innerpath = (BitmapHeapPath *) best_path->innerjoinpath; |