David Rowley 4297a35196 Fix possible issue of a WindowFunc being in the wrong WindowClause ... ed1a88dda made it so WindowClauses can be merged when all window functions belonging to the WindowClause can equally well use some other WindowClause without any behavioral changes. When that optimization applies, the WindowFunc's "winref" gets adjusted to reference the new WindowClause. That commit does not work well with the deduplication logic in find_window_functions(), which only added the WindowFunc to the list when there wasn't already an identical WindowFunc in the list. That deduplication logic meant that the duplicate WindowFunc wouldn't get the "winref" changed when optimize_window_clauses() was able to swap the WindowFunc to another WindowClause. This could lead to the following error in the unlikely event that the deduplication code did something and the duplicate WindowFunc happened to be moved into another WindowClause. ERROR: WindowFunc with winref 2 assigned to WindowAgg with winref 1 As it turns out, the deduplication logic in find_window_functions() is pretty bogus. It might have done something when added, as that code predates b8d7f053c, which changed how projections work. As it turns out, at least now we *will* evaluate the duplicate WindowFuncs. All that the deduplication code seems to do today is assist in underestimating the WindowAggPath costs due to not counting the evaluation costs of duplicate WindowFuncs. Ideally the fix would be to remove the deduplication code, but that could result in changes to the plan costs, as duplicate WindowFuncs would then be costed. Instead, let's play it safe and shift the deduplication code so it runs after the other processing in optimize_window_clauses(). Backpatch only as far as v16 as there doesn't seem to be any other harm done by the WindowFunc deduplication code before then. This issue was fixed in master by 7027dd499. Reported-by: Meng Zhang <mza117jc@gmail.com> Author: Meng Zhang <mza117jc@gmail.com> Author: David Rowley <dgrowleyml@gmail.com> Discussion: https://postgr.es/m/CAErYLFAuxmW0UVdgrz7iiuNrxGQnFK_OP9hBD5CUzRgjrVrz=Q@mail.gmail.com Backpatch-through: 16		2026-01-26 23:47:37 +13:00
..
backend	Fix possible issue of a WindowFunc being in the wrong WindowClause	2026-01-26 23:47:37 +13:00
bin	pg_waldump: Relax LSN comparison check in TAP test	2026-01-14 16:02:39 +09:00
common	With GB18030, prevent SIGSEGV from reading past end of allocation.	2025-05-05 04:52:07 -07:00
fe_utils	In fmtIdEnc(), handle failure of enlargePQExpBuffer().	2025-02-16 12:46:35 -05:00
include	Fix trigger transition table capture for MERGE in CTE queries.	2026-01-24 11:30:50 +00:00
interfaces	Fix printf format string warning on MinGW.	2025-12-21 21:14:54 +13:00
makefiles	Use --strip-unneeded when stripping static libraries with GNU strip.	2023-04-20 18:12:32 -04:00
pl	Translation updates	2025-11-10 13:04:09 +01:00
port	Fix O_CLOEXEC flag handling in Windows port.	2025-12-10 09:11:19 +13:00
template	Use unnamed POSIX semaphores on Cygwin.	2023-01-06 10:33:28 +13:00
test	Fix trigger transition table capture for MERGE in CTE queries.	2026-01-24 11:30:50 +00:00
timezone	Update time zone data files to tzdata release 2025c.	2026-01-18 14:55:01 -05:00
tools	For inplace update, send nontransactional invalidations.	2025-12-16 16:13:55 -08:00
tutorial	Pre-beta mechanical code beautification.	2023-05-19 17:24:48 -04:00
.gitignore
DEVELOPERS
Makefile	Integrate pg_bsd_indent into our build/test infrastructure.	2023-02-12 12:22:21 -05:00
Makefile.global.in	Don't put library-supplied -L/-I switches before user-supplied ones.	2025-07-29 15:17:41 -04:00
Makefile.shlib	Stop using "-multiply_defined suppress" on macOS.	2023-09-26 21:06:21 -04:00
meson.build	Integrate pg_bsd_indent into our build/test infrastructure.	2023-02-12 12:22:21 -05:00
nls-global.mk	Fix update-po for the PGXS case	2025-10-16 20:21:05 +02:00