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

Tatsuo Ishii <ishii@postgresql.org>

From: Tatsuo Ishii <ishii@postgresql.org>

To: tgl@sss.pgh.pa.us

Cc: pramsey@cleverelephant.ca, 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: 2025-10-11T09:11:03Z

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 think it should be set up
>> so that if the window function fails to call that, then something in
>> mainline execution of nodeWindowAgg.c throws an error when there had
>> been a RESPECT/IGNORE NULLS option.  With that idea, you could drop
>> the allowNullTreatment argument and just have the window functions
>> that support this syntax call something named along the lines of
>> WinAllowNullTreatmentOption.
> 
> Does that mean all user defined window functions start to fail after
> upgrading to PostgreSQL 19?  I am not sure if it's acceptable for
> extension developers and their users.

Probably I misunderstood what you said. Now I realize what you are
suggesting was, throwing an error *only* when a RESPECT/IGNORE NULLS
option is given and the function did not call
WinAllowNullTreatmentOption. If the option is not given, no error is
thrown even if WinAllowNullTreatmentOption is not called. I am okay
with this direction. I will post a patch for this.

Best regards,
--
Tatsuo Ishii
SRA OSS K.K.
English: http://www.sraoss.co.jp/index_en/
Japanese:http://www.sraoss.co.jp