From 72bd38cc99a15da6f97373fae98027c908c398ea Mon Sep 17 00:00:00 2001 From: Alexander Korotkov Date: Mon, 8 Apr 2024 01:27:28 +0300 Subject: Transform OR clauses to ANY expression Replace (expr op C1) OR (expr op C2) ... with expr op ANY(ARRAY[C1, C2, ...]) on the preliminary stage of optimization when we are still working with the expression tree. Here Cn is a n-th constant expression, 'expr' is non-constant expression, 'op' is an operator which returns boolean result and has a commuter (for the case of reverse order of constant and non-constant parts of the expression, like 'Cn op expr'). Sometimes it can lead to not optimal plan. This is why there is a or_to_any_transform_limit GUC. It specifies a threshold value of length of arguments in an OR expression that triggers the OR-to-ANY transformation. Generally, more groupable OR arguments mean that transformation will be more likely to win than to lose. Discussion: https://postgr.es/m/567ED6CA.2040504%40sigaev.ru Author: Alena Rybakina Author: Andrey Lepikhov Reviewed-by: Peter Geoghegan Reviewed-by: Ranier Vilela Reviewed-by: Alexander Korotkov Reviewed-by: Robert Haas Reviewed-by: Jian He --- src/backend/utils/misc/postgresql.conf.sample | 1 + 1 file changed, 1 insertion(+) (limited to 'src/backend/utils/misc/postgresql.conf.sample') diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample index 2166ea4a87a..15b14ba8507 100644 --- a/src/backend/utils/misc/postgresql.conf.sample +++ b/src/backend/utils/misc/postgresql.conf.sample @@ -392,6 +392,7 @@ # - Planner Method Configuration - #enable_async_append = on +#or_to_any_transform_limit = 0 #enable_bitmapscan = on #enable_gathermerge = on #enable_hashagg = on -- cgit v1.2.3