diff options
| author | Jeff Davis <jdavis@postgresql.org> | 2020-07-12 16:46:19 -0700 |
|---|---|---|
| committer | Jeff Davis <jdavis@postgresql.org> | 2020-07-12 22:59:32 -0700 |
| commit | 0babd109801e5ecd90df29589c23c6daf3ae69f7 (patch) | |
| tree | 74794f9fdba29a17a5ff85c586fd4e6cddecdbf3 /src | |
| parent | d973747281caece520236e93d255c654cc613ec9 (diff) | |
| download | postgresql-0babd109801e5ecd90df29589c23c6daf3ae69f7.tar.gz postgresql-0babd109801e5ecd90df29589c23c6daf3ae69f7.zip | |
Revert "Use CP_SMALL_TLIST for hash aggregate"
This reverts commit 4cad2534da6d17067d98cf04be2dfc1bda8f2cd0 due to a
performance regression. It will be replaced by a new approach in an
upcoming commit.
Reported-by: Andres Freund
Discussion: https://postgr.es/m/20200614181418.mx4bvljmfkkhoqzl@alap3.anarazel.de
Backpatch-through: 13
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/optimizer/plan/createplan.c | 28 |
1 files changed, 4 insertions, 24 deletions
diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c index eb9543f6add..9941dfe65e4 100644 --- a/src/backend/optimizer/plan/createplan.c +++ b/src/backend/optimizer/plan/createplan.c @@ -2113,22 +2113,12 @@ create_agg_plan(PlannerInfo *root, AggPath *best_path) Plan *subplan; List *tlist; List *quals; - int flags; /* * Agg can project, so no need to be terribly picky about child tlist, but - * we do need grouping columns to be available. We are a bit more careful - * with hash aggregate, where we explicitly request small tlist to - * minimize I/O needed for spilling (we can't be sure spilling won't be - * necessary, so we just do it every time). + * we do need grouping columns to be available */ - flags = CP_LABEL_TLIST; - - /* ensure small tlist for hash aggregate */ - if (best_path->aggstrategy == AGG_HASHED) - flags |= CP_SMALL_TLIST; - - subplan = create_plan_recurse(root, best_path->subpath, flags); + subplan = create_plan_recurse(root, best_path->subpath, CP_LABEL_TLIST); tlist = build_path_tlist(root, &best_path->path); @@ -2210,7 +2200,6 @@ create_groupingsets_plan(PlannerInfo *root, GroupingSetsPath *best_path) int maxref; List *chain; ListCell *lc; - int flags; /* Shouldn't get here without grouping sets */ Assert(root->parse->groupingSets); @@ -2218,18 +2207,9 @@ create_groupingsets_plan(PlannerInfo *root, GroupingSetsPath *best_path) /* * Agg can project, so no need to be terribly picky about child tlist, but - * we do need grouping columns to be available. We are a bit more careful - * with hash aggregate, where we explicitly request small tlist to - * minimize I/O needed for spilling (we can't be sure spilling won't be - * necessary, so we just do it every time). + * we do need grouping columns to be available */ - flags = CP_LABEL_TLIST; - - /* ensure small tlist for hash aggregate */ - if (best_path->aggstrategy == AGG_HASHED) - flags |= CP_SMALL_TLIST; - - subplan = create_plan_recurse(root, best_path->subpath, flags); + subplan = create_plan_recurse(root, best_path->subpath, CP_LABEL_TLIST); /* * Compute the mapping from tleSortGroupRef to column index in the child's |