v1-0001-Reduce-planning-time-for-large-NOT-IN-lists-conta.patch

From 86914f44a37b3c9afbd18b333eb5c451f41ce65b Mon Sep 17 00:00:00 2001
From: Ilia Evdokimov <ilya.evdokimov@tantorlabs.ru>
Date: Wed, 18 Feb 2026 17:06:35 +0300
Subject: [PATCH v1] Reduce planning time for large NOT IN lists containing
 NULL

For x <> ALL (...) / x NOT IN (...), the presence of a NULL element
makes the selectivity 0.0.

The planner currently still iterates over all elements and computes
per-element selectivity, even though the final result is known.

Add an early NULL check for constant arrays and immediately return
0.0 under ALL semantics.

This reduces planning time for large NOT IN / <> ALL lists without
changing semantics.
---
 src/backend/utils/adt/selfuncs.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index 29fec655593..a0b57bd57aa 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -2025,6 +2025,9 @@ scalararraysel(PlannerInfo *root,
 						  elmlen, elmbyval, elmalign,
 						  &elem_values, &elem_nulls, &num_elems);
 
+		if (!useOr && memchr(elem_nulls, true, num_elems) != NULL)
+			return (Selectivity) 0.0;
+
 		/*
 		 * For generic operators, we assume the probability of success is
 		 * independent for each array element.  But for "= ANY" or "<> ALL",
-- 
2.34.1