From 92e03900de9015ce30bf7bced45a1070c0380957 Mon Sep 17 00:00:00 2001 From: "yizhi.fzh" Date: Tue, 2 Apr 2024 10:39:03 +0800 Subject: [PATCH v1 5/8] use the pre-calculated RestrictInfo->left|right_relids It should has better performance than pull_varnos and easier to understand. --- src/backend/statistics/extended_stats.c | 35 +++++-------------------- 1 file changed, 6 insertions(+), 29 deletions(-) diff --git a/src/backend/statistics/extended_stats.c b/src/backend/statistics/extended_stats.c index 4e6f604273..0deb0c3c55 100644 --- a/src/backend/statistics/extended_stats.c +++ b/src/backend/statistics/extended_stats.c @@ -2809,7 +2809,7 @@ statext_is_supported_join_clause(PlannerInfo *root, Node *clause) Oid oprsel; RestrictInfo *rinfo; OpExpr *opclause; - ListCell *lc; + int left_relid, right_relid; /* * evaluation as a restriction clause, either at scan node or forced @@ -2825,10 +2825,6 @@ statext_is_supported_join_clause(PlannerInfo *root, Node *clause) rinfo = (RestrictInfo *) clause; clause = (Node *) rinfo->clause; - /* is it referencing multiple relations? */ - if (bms_membership(rinfo->clause_relids) != BMS_MULTIPLE) - return false; - /* we only support simple operator clauses for now */ if (!is_opclause(clause)) return false; @@ -2851,8 +2847,6 @@ statext_is_supported_join_clause(PlannerInfo *root, Node *clause) * which is still technically an opclause, but we can't match it to * extended statistics in a simple way. * - * XXX This also means we require rinfo->clause_relids to have 2 rels. - * * XXX Also check it's not expression on system attributes, which we * don't allow in extended statistics. * @@ -2861,30 +2855,13 @@ statext_is_supported_join_clause(PlannerInfo *root, Node *clause) * or something like that. We could do "cartesian product" of the MCV * stats and restrict it using this condition. */ - foreach (lc, opclause->args) - { - Bitmapset *varnos = NULL; - Node *expr = (Node *) lfirst(lc); - - varnos = pull_varnos(root, expr); - /* - * No argument should reference more than just one relation. - * - * This effectively means each side references just two relations. - * If there's no relation on one side, it's a Const, and the other - * side has to be either Const or Expr with a single rel. In which - * case it can't be a join clause. - */ - if (bms_num_members(varnos) > 1) - return false; + if (!bms_get_singleton_member(rinfo->left_relids, &left_relid) || + !bms_get_singleton_member(rinfo->right_relids, &right_relid)) + return false; - /* - * XXX Maybe check that both relations have extended statistics - * (no point in considering the clause as useful without it). But - * we'll do that check later anyway, so keep this cheap. - */ - } + if (left_relid == right_relid) + return false; return true; } -- 2.34.1