Re: Add RESPECT/IGNORE NULLS and FROM FIRST/LAST options

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>

To: Tatsuo Ishii <ishii@postgresql.org>

Cc: ojford@gmail.com, peter@eisentraut.org, li.evan.chao@gmail.com, krasiyan@gmail.com, vik@postgresfriends.org, andrew@tao11.riddles.org.uk, david@fetter.org, pgsql-hackers@lists.postgresql.org

Date: 2025-10-05T16:35:46Z

Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

Fix coding style with "else".
- 20628b62e46e 19 (unreleased) landed
Fix multi WinGetFuncArgInFrame/Partition calls with IGNORE NULLS.
- 2d7b247cb414 19 (unreleased) landed
Fix Coverity issue reported in commit 2273fa32bce.
- dd766a441d69 19 (unreleased) landed
Use ereport rather than elog in WinCheckAndInitializeNullTreatment.
- 5f3808646f67 19 (unreleased) landed
Avoid uninitialized-variable warnings from older compilers.
- 71540dcdcb22 19 (unreleased) cited
Fix Coverity issues reported in commit 25a30bbd423.
- 2273fa32bce7 19 (unreleased) landed
Improve EXPLAIN's display of window functions.
- 8b1b342544b6 18.0 cited
Automatically generate node support functions
- 964d01ae90c3 16.0 cited

I wrote:
> ... also that WinGetFuncArgInPartition is dereferencing
> a possibly-null "isout" pointer at several places

Looking around, there is only one in-core caller of
WinGetFuncArgInPartition, and it does pass a valid "isout" pointer,
explaining why this inconsistency wasn't obvious in testing.
There are outside callers though according to Debian Code Search,
and at least PostGIS is one that passes a null pointer.

As Alvaro notes nearby, this function is ridiculously complicated
already.  I'm tempted to remove the API allowance for isout == NULL,
and thereby simplify the code slightly, rather than complicate it more
by continuing to allow that.  We'd have to warn the PostGIS people
about the API change though.

			regards, tom lane