From 44527135526087bca6ebed80d010d3334a4ab5ff Mon Sep 17 00:00:00 2001 From: Ilia Evdokimov Date: Thu, 22 Oct 2026 12:31:03 +0300 Subject: [PATCH v1] Fix NOT selectivity estimates for nullable boolean expressions Use booltestsel(IS_FALSE) when statistics are available for the argument of NOT, so NULL values are excluded from the estimated matching rows. Retain the existing recursive estimate when statistics are unavailable. --- src/backend/optimizer/path/clausesel.c | 26 +++++++++++++++++++------- 1 file changed, 19 insertions(+), 7 deletions(-) diff --git a/src/backend/optimizer/path/clausesel.c b/src/backend/optimizer/path/clausesel.c index 25c4d177ad9..631752dbced 100644 --- a/src/backend/optimizer/path/clausesel.c +++ b/src/backend/optimizer/path/clausesel.c @@ -797,13 +797,25 @@ clause_selectivity_ext(PlannerInfo *root, } else if (is_notclause(clause)) { - /* inverse of the selectivity of the underlying clause */ - s1 = 1.0 - clause_selectivity_ext(root, - (Node *) get_notclausearg((Expr *) clause), - varRelid, - jointype, - sjinfo, - use_extended_stats); + Node *arg = (Node *) get_notclausearg((Expr *) clause); + VariableStatData vardata; + + examine_variable(root, arg, varRelid, &vardata); + if (HeapTupleIsValid(vardata.statsTuple)) + { + /* Use statistics to select FALSE values, excluding NULLs. */ + s1 = booltestsel(root, IS_FALSE, arg, varRelid, jointype, sjinfo); + } + else + { + /* Otherwise, estimate the underlying clause */ + s1 = 1.0 - clause_selectivity_ext(root, arg, + varRelid, + jointype, + sjinfo, + use_extended_stats); + } + ReleaseVariableStats(vardata); } else if (is_andclause(clause)) { -- 2.34.1