From bf333a5428aae92f1acfeba206d70ff32868ef69 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Sat, 27 Aug 2005 22:37:00 +0000 Subject: [PATCH] cost_agg really ought to charge something per output tuple; else there are cases where it appears to have zero run cost. --- src/backend/optimizer/path/costsize.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/src/backend/optimizer/path/costsize.c b/src/backend/optimizer/path/costsize.c index 55a5b1321e..75b6928209 100644 --- a/src/backend/optimizer/path/costsize.c +++ b/src/backend/optimizer/path/costsize.c @@ -872,7 +872,7 @@ cost_agg(Path *path, PlannerInfo *root, * for grouping comparisons. * * We will produce a single output tuple if not grouping, and a tuple per - * group otherwise. + * group otherwise. We charge cpu_tuple_cost for each output tuple. * * Note: in this cost model, AGG_SORTED and AGG_HASHED have exactly the * same total CPU cost, but AGG_SORTED has lower startup cost. If the @@ -888,7 +888,7 @@ cost_agg(Path *path, PlannerInfo *root, startup_cost = input_total_cost; startup_cost += cpu_operator_cost * (input_tuples + 1) * numAggs; /* we aren't grouping */ - total_cost = startup_cost; + total_cost = startup_cost + cpu_tuple_cost; } else if (aggstrategy == AGG_SORTED) { @@ -899,6 +899,7 @@ cost_agg(Path *path, PlannerInfo *root, total_cost += cpu_operator_cost * input_tuples * numGroupCols; total_cost += cpu_operator_cost * input_tuples * numAggs; total_cost += cpu_operator_cost * numGroups * numAggs; + total_cost += cpu_tuple_cost * numGroups; } else { @@ -908,6 +909,7 @@ cost_agg(Path *path, PlannerInfo *root, startup_cost += cpu_operator_cost * input_tuples * numAggs; total_cost = startup_cost; total_cost += cpu_operator_cost * numGroups * numAggs; + total_cost += cpu_tuple_cost * numGroups; } path->startup_cost = startup_cost; -- 2.39.5