On 2/20/26 16:25, Ilia Evdokimov wrote:
I've moved the NULL check higher, placing it immediately after DatumGetArrayTypeP(). This allows us to detect the presence of NULL elements before decontructing the array.
Sorry, I forgot to attach the patch in my previous mail. Attaching it now. -- Best regards. Ilia Evdokimov, Tantor Labs LLC, https://tantorlabs.com/
From 909e4683a400f0aa613fc77fa4bb6f0208c75f78 Mon Sep 17 00:00:00 2001 From: Ilia Evdokimov <[email protected]> Date: Fri, 20 Feb 2026 16:14:12 +0300 Subject: [PATCH v3] 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 | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c index 29fec655593..624356a30b2 100644 --- a/src/backend/utils/adt/selfuncs.c +++ b/src/backend/utils/adt/selfuncs.c @@ -2018,6 +2018,11 @@ scalararraysel(PlannerInfo *root, if (arrayisnull) /* qual can't succeed if null array */ return (Selectivity) 0.0; arrayval = DatumGetArrayTypeP(arraydatum); + + /* Selectivity of "WHERE x NOT IN (NULL, ... )" is always 0 */ + if (!useOr && ARR_HASNULL(arrayval)) + return (Selectivity) 0.0; + get_typlenbyvalalign(ARR_ELEMTYPE(arrayval), &elmlen, &elmbyval, &elmalign); deconstruct_array(arrayval, @@ -2115,6 +2120,10 @@ scalararraysel(PlannerInfo *root, List *args; Selectivity s2; + /* Selectivity of "WHERE x NOT IN (NULL, ... )" is always 0 */ + if (!useOr && IsA(elem, Const) && ((Const *) elem)->constisnull) + return (Selectivity) 0.0; + /* * Theoretically, if elem isn't of nominal_element_type we should * insert a RelabelType, but it seems unlikely that any operator -- 2.34.1
