diff options
Diffstat (limited to 'src/backend/optimizer/plan/planagg.c')
| -rw-r--r-- | src/backend/optimizer/plan/planagg.c | 38 |
1 files changed, 24 insertions, 14 deletions
diff --git a/src/backend/optimizer/plan/planagg.c b/src/backend/optimizer/plan/planagg.c index 2b7934b686f..a32a06fc28d 100644 --- a/src/backend/optimizer/plan/planagg.c +++ b/src/backend/optimizer/plan/planagg.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/optimizer/plan/planagg.c,v 1.47 2009/12/15 17:57:46 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/optimizer/plan/planagg.c,v 1.48 2010/01/01 21:53:49 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -37,7 +37,7 @@ typedef struct Oid aggfnoid; /* pg_proc Oid of the aggregate */ Oid aggsortop; /* Oid of its sort operator */ Expr *target; /* expression we are aggregating on */ - Expr *notnulltest; /* expression for "target IS NOT NULL" */ + NullTest *notnulltest; /* expression for "target IS NOT NULL" */ IndexPath *path; /* access path for index scan */ Cost pathcost; /* estimated cost to fetch first row */ bool nulls_first; /* null ordering direction matching index */ @@ -308,7 +308,7 @@ build_minmax_path(PlannerInfo *root, RelOptInfo *rel, MinMaxAggInfo *info) ntest = makeNode(NullTest); ntest->nulltesttype = IS_NOT_NULL; ntest->arg = copyObject(info->target); - info->notnulltest = (Expr *) ntest; + info->notnulltest = ntest; /* * Build list of existing restriction clauses plus the notnull test. We @@ -475,7 +475,7 @@ make_agg_subplan(PlannerInfo *root, MinMaxAggInfo *info) PlannerInfo subroot; Query *subparse; Plan *plan; - Plan *iplan; + IndexScan *iplan; TargetEntry *tle; SortGroupClause *sortcl; @@ -529,16 +529,13 @@ make_agg_subplan(PlannerInfo *root, MinMaxAggInfo *info) * * Also we must add a "WHERE target IS NOT NULL" restriction to the * indexscan, to be sure we don't return a NULL, which'd be contrary to - * the standard behavior of MIN/MAX. XXX ideally this should be done - * earlier, so that the selectivity of the restriction could be included - * in our cost estimates. But that looks painful, and in most cases the - * fraction of NULLs isn't high enough to change the decision. + * the standard behavior of MIN/MAX. * * The NOT NULL qual has to go on the actual indexscan; create_plan might * have stuck a gating Result atop that, if there were any pseudoconstant * quals. * - * We can skip adding the NOT NULL qual if it's redundant with either an + * We can skip adding the NOT NULL qual if it duplicates either an * already-given WHERE condition, or a clause of the index predicate. */ plan = create_plan(&subroot, (Path *) info->path); @@ -546,14 +543,27 @@ make_agg_subplan(PlannerInfo *root, MinMaxAggInfo *info) plan->targetlist = copyObject(subparse->targetList); if (IsA(plan, Result)) - iplan = plan->lefttree; + iplan = (IndexScan *) plan->lefttree; else - iplan = plan; - Assert(IsA(iplan, IndexScan)); + iplan = (IndexScan *) plan; + if (!IsA(iplan, IndexScan)) + elog(ERROR, "result of create_plan(IndexPath) isn't an IndexScan"); - if (!list_member(iplan->qual, info->notnulltest) && + if (!list_member(iplan->indexqualorig, info->notnulltest) && !list_member(info->path->indexinfo->indpred, info->notnulltest)) - iplan->qual = lcons(info->notnulltest, iplan->qual); + { + NullTest *ntest; + + /* Need a "fixed" copy as well as the original */ + ntest = copyObject(info->notnulltest); + ntest->arg = (Expr *) fix_indexqual_operand((Node *) ntest->arg, + info->path->indexinfo); + + iplan->indexqual = lappend(iplan->indexqual, + ntest); + iplan->indexqualorig = lappend(iplan->indexqualorig, + info->notnulltest); + } plan = (Plan *) make_limit(plan, subparse->limitOffset, |