diff options
Diffstat (limited to 'src/backend/optimizer/plan/planner.c')
| -rw-r--r-- | src/backend/optimizer/plan/planner.c | 24 |
1 files changed, 23 insertions, 1 deletions
diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c index e886b88184e..3b8981021af 100644 --- a/src/backend/optimizer/plan/planner.c +++ b/src/backend/optimizer/plan/planner.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/planner.c,v 1.136 2002/12/19 23:25:01 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/planner.c,v 1.137 2003/01/13 00:29:25 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -966,6 +966,7 @@ grouping_planner(Query *parse, double tuple_fraction) List *sub_tlist; List *group_pathkeys; AttrNumber *groupColIdx = NULL; + QualCost tlist_cost; double sub_tuple_fraction; Path *cheapest_path; Path *sorted_path; @@ -1452,6 +1453,27 @@ grouping_planner(Query *parse, double tuple_fraction) */ result_plan->targetlist = sub_tlist; } + /* + * Also, account for the cost of evaluation of the sub_tlist. + * + * Up to now, we have only been dealing with "flat" tlists, containing + * just Vars. So their evaluation cost is zero according to the + * model used by cost_qual_eval() (or if you prefer, the cost is + * factored into cpu_tuple_cost). Thus we can avoid accounting for + * tlist cost throughout query_planner() and subroutines. + * But now we've inserted a tlist that might contain actual operators, + * sub-selects, etc --- so we'd better account for its cost. + * + * Below this point, any tlist eval cost for added-on nodes should + * be accounted for as we create those nodes. Presently, of the + * node types we can add on, only Agg and Group project new tlists + * (the rest just copy their input tuples) --- so make_agg() and + * make_group() are responsible for computing the added cost. + */ + cost_qual_eval(&tlist_cost, sub_tlist); + result_plan->startup_cost += tlist_cost.startup; + result_plan->total_cost += tlist_cost.startup + + tlist_cost.per_tuple * result_plan->plan_rows; /* * Insert AGG or GROUP node if needed, plus an explicit sort step |