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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2005-08-27 22:37:00 +0000 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2005-08-27 22:37:00 +0000 |
| commit | 974e3cf30afe783c26cfcdc0658833a682f6b357 (patch) | |
| tree | 1ffd184cdf50d4ae847f3476e856c9ac59d00c6b /src | |
| parent | 4e5fbb34b361102df41642a6ed9676b8b6a1e75f (diff) | |
| download | postgresql-974e3cf30afe783c26cfcdc0658833a682f6b357.tar.gz postgresql-974e3cf30afe783c26cfcdc0658833a682f6b357.zip | |
cost_agg really ought to charge something per output tuple; else there
are cases where it appears to have zero run cost.
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/optimizer/path/costsize.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/src/backend/optimizer/path/costsize.c b/src/backend/optimizer/path/costsize.c index b70b544e221..24af7afe799 100644 --- a/src/backend/optimizer/path/costsize.c +++ b/src/backend/optimizer/path/costsize.c @@ -49,7 +49,7 @@ * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/optimizer/path/costsize.c,v 1.146 2005/06/05 22:32:55 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/optimizer/path/costsize.c,v 1.147 2005/08/27 22:37:00 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -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; |