From ba3e76cc571eba3dea19c9465ff15ac3ac186576 Mon Sep 17 00:00:00 2001 From: Tomas Vondra Date: Tue, 7 Apr 2020 16:43:18 +0200 Subject: Consider Incremental Sort paths at additional places Commit d2d8a229bc introduced Incremental Sort, but it was considered only in create_ordered_paths() as an alternative to regular Sort. There are many other places that require sorted input and might benefit from considering Incremental Sort too. This patch modifies a number of those places, but not all. The concern is that just adding Incremental Sort to any place that already adds Sort may increase the number of paths considered, negatively affecting planning time, without any benefit. So we've taken a more conservative approach, based on analysis of which places do affect a set of queries that did seem practical. This means some less common queries may not benefit from Incremental Sort yet. Author: Tomas Vondra Reviewed-by: James Coleman Discussion: https://postgr.es/m/CAPpHfds1waRZ=NOmueYq0sx1ZSCnt+5QJvizT8ndT2=etZEeAQ@mail.gmail.com --- src/include/optimizer/paths.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'src/include/optimizer/paths.h') diff --git a/src/include/optimizer/paths.h b/src/include/optimizer/paths.h index ab61f306cb9..10b6e810796 100644 --- a/src/include/optimizer/paths.h +++ b/src/include/optimizer/paths.h @@ -54,6 +54,8 @@ extern RelOptInfo *standard_join_search(PlannerInfo *root, int levels_needed, extern void generate_gather_paths(PlannerInfo *root, RelOptInfo *rel, bool override_rows); +extern void generate_useful_gather_paths(PlannerInfo *root, RelOptInfo *rel, + bool override_rows); extern int compute_parallel_worker(RelOptInfo *rel, double heap_pages, double index_pages, int max_workers); extern void create_partial_bitmap_paths(PlannerInfo *root, RelOptInfo *rel, @@ -132,6 +134,7 @@ extern EquivalenceClass *get_eclass_for_sort_expr(PlannerInfo *root, Index sortref, Relids rel, bool create_it); +extern Expr *find_em_expr_for_rel(EquivalenceClass *ec, RelOptInfo *rel); extern void generate_base_implied_equalities(PlannerInfo *root); extern List *generate_join_implied_equalities(PlannerInfo *root, Relids join_relids, -- cgit v1.2.3