diff options
Diffstat (limited to 'src/backend/optimizer/plan/planner.c')
| -rw-r--r-- | src/backend/optimizer/plan/planner.c | 21 |
1 files changed, 17 insertions, 4 deletions
diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c index 8679e9ecf9a..74e7258bba2 100644 --- a/src/backend/optimizer/plan/planner.c +++ b/src/backend/optimizer/plan/planner.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/optimizer/plan/planner.c,v 1.231 2008/04/01 00:48:33 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/optimizer/plan/planner.c,v 1.232 2008/04/17 21:22:14 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -957,9 +957,23 @@ grouping_planner(PlannerInfo *root, double tuple_fraction) * Normal case --- create a plan according to query_planner's * results. */ + bool need_sort_for_grouping = false; + result_plan = create_plan(root, best_path); current_pathkeys = best_path->pathkeys; + /* Detect if we'll need an explicit sort for grouping */ + if (parse->groupClause && !use_hashed_grouping && + !pathkeys_contained_in(group_pathkeys, current_pathkeys)) + { + need_sort_for_grouping = true; + /* + * Always override query_planner's tlist, so that we don't + * sort useless data from a "physical" tlist. + */ + need_tlist_eval = true; + } + /* * create_plan() returns a plan with just a "flat" tlist of * required Vars. Usually we need to insert the sub_tlist as the @@ -1054,8 +1068,7 @@ grouping_planner(PlannerInfo *root, double tuple_fraction) if (parse->groupClause) { - if (!pathkeys_contained_in(group_pathkeys, - current_pathkeys)) + if (need_sort_for_grouping) { result_plan = (Plan *) make_sort_from_groupcols(root, @@ -1098,7 +1111,7 @@ grouping_planner(PlannerInfo *root, double tuple_fraction) * Add an explicit sort if we couldn't make the path come out * the way the GROUP node needs it. */ - if (!pathkeys_contained_in(group_pathkeys, current_pathkeys)) + if (need_sort_for_grouping) { result_plan = (Plan *) make_sort_from_groupcols(root, |