From d228d9734e70b4f43ad824d736fb1279d2aad5fc Mon Sep 17 00:00:00 2001 From: "yizhi.fzh" Date: Mon, 8 Apr 2024 11:43:37 +0800 Subject: [PATCH v1 2/2] Fast path for empty clauselist in clauselist_selectivity_ext It should be common in the real life, for example: SELECT * FROM t1, t2 WHERE t1.a = t2.a AND t1.a > 3; clauses == NIL at the scan level of t2. This would also make some debug life happier. --- src/backend/optimizer/path/clausesel.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/src/backend/optimizer/path/clausesel.c b/src/backend/optimizer/path/clausesel.c index 0ab021c1e8..dff498d581 100644 --- a/src/backend/optimizer/path/clausesel.c +++ b/src/backend/optimizer/path/clausesel.c @@ -128,6 +128,9 @@ clauselist_selectivity_ext(PlannerInfo *root, ListCell *l; int listidx; + if (list_length(clauses) == 0) + return 1.0; + /* * If there's exactly one clause, just go directly to * clause_selectivity_ext(). None of what we might do below is relevant. -- 2.34.1