diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/optimizer/plan/createplan.c | 28 |
1 files changed, 24 insertions, 4 deletions
diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c index 9941dfe65e4..744eed187d4 100644 --- a/src/backend/optimizer/plan/createplan.c +++ b/src/backend/optimizer/plan/createplan.c @@ -2113,12 +2113,22 @@ 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 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). */ - subplan = create_plan_recurse(root, best_path->subpath, CP_LABEL_TLIST); + 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); tlist = build_path_tlist(root, &best_path->path); @@ -2200,6 +2210,7 @@ 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); @@ -2207,9 +2218,18 @@ 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 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). */ - subplan = create_plan_recurse(root, best_path->subpath, CP_LABEL_TLIST); + 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); /* * Compute the mapping from tleSortGroupRef to column index in the child's |