From 463c085852be921199b7a6d0987378d55145e41c Mon Sep 17 00:00:00 2001 From: Andrey Lepikhov Date: Mon, 11 Jul 2022 12:25:43 +0500 Subject: [PATCH] Use Index path with the best selectivity estimation --- src/backend/optimizer/util/pathnode.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/src/backend/optimizer/util/pathnode.c b/src/backend/optimizer/util/pathnode.c index 483c4f4137..a8d7f22343 100644 --- a/src/backend/optimizer/util/pathnode.c +++ b/src/backend/optimizer/util/pathnode.c @@ -207,6 +207,20 @@ compare_path_costs_fuzzily(Path *path1, Path *path2, double fuzz_factor) /* ... but path2 fuzzily worse on startup, so path1 wins */ return COSTS_BETTER1; } + if (IsA(path1, IndexPath) && IsA(path2, IndexPath)) + { + /* + * Couldn't differ value of the paths. Last chance - if these paths + * are index paths - use the path with the lower selectivity value. + */ + if (((IndexPath *) path1)->indexselectivity < + ((IndexPath *) path2)->indexselectivity) + return COSTS_BETTER1; + + if (((IndexPath *) path1)->indexselectivity > + ((IndexPath *) path2)->indexselectivity) + return COSTS_BETTER2; + } /* fuzzily the same on both costs */ return COSTS_EQUAL; -- 2.34.1