diff options
Diffstat (limited to 'src/backend/optimizer/path/costsize.c')
| -rw-r--r-- | src/backend/optimizer/path/costsize.c | 20 |
1 files changed, 11 insertions, 9 deletions
diff --git a/src/backend/optimizer/path/costsize.c b/src/backend/optimizer/path/costsize.c index c14692d5b97..e70d2a7abee 100644 --- a/src/backend/optimizer/path/costsize.c +++ b/src/backend/optimizer/path/costsize.c @@ -42,7 +42,7 @@ * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/optimizer/path/costsize.c,v 1.52 2000/02/15 20:49:16 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/optimizer/path/costsize.c,v 1.53 2000/03/14 02:23:14 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -687,8 +687,8 @@ cost_qual_eval_walker(Node *node, Cost *total) * (We assume that sub-selects that can be executed as * InitPlans have already been removed from the expression.) * - * NOTE: this logic should agree with make_subplan in - * subselect.c. + * NOTE: this logic should agree with the estimates used by + * make_subplan() in plan/subselect.c. */ { SubPlan *subplan = (SubPlan *) expr->oper; @@ -701,16 +701,18 @@ cost_qual_eval_walker(Node *node, Cost *total) subcost = plan->startup_cost + (plan->total_cost - plan->startup_cost) / plan->plan_rows; } - else if (subplan->sublink->subLinkType == EXPR_SUBLINK) - { - /* assume we need all tuples */ - subcost = plan->total_cost; - } - else + else if (subplan->sublink->subLinkType == ALL_SUBLINK || + subplan->sublink->subLinkType == ANY_SUBLINK) { /* assume we need 50% of the tuples */ subcost = plan->startup_cost + 0.50 * (plan->total_cost - plan->startup_cost); + /* XXX what if subplan has been materialized? */ + } + else + { + /* assume we need all tuples */ + subcost = plan->total_cost; } *total += subcost; } |