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

Oliver Ford <ojford@gmail.com>

From: Oliver Ford <ojford@gmail.com>

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

Cc: Tatsuo Ishii <ishii@postgresql.org>, vik@postgresfriends.org, pgsql-hackers@postgresql.org, andrew@tao11.riddles.org.uk, david@fetter.org, krasiyan@gmail.com

Date: 2025-01-20T19:09:38Z

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

On Mon, Jan 20, 2025 at 12:31 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>
> Tatsuo Ishii <ishii@postgresql.org> writes:
> >> I would think that
> >> IGNORE NULLS is potentially useful for user-defined window functions,
> >> and we should not be building anything that restricts the feature to
> >> specific functions.
>
> > So you want to allow to use IGNORE NULLS to other built-in window
> > functions?
>
> No, there needs to be a way for the individual window function to
> throw error if that's specified for a function that can't handle it.
> I'm just saying I don't want that to be hard-wired in some centralized
> spot.

Would it be acceptable to add a bool column to pg_proc, say
"pronulltreatment"? It would default to false, and an error would be
thrown if the null clause is specified for a function where it's set
to false?