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

Oliver Ford <ojford@gmail.com>

From: Oliver Ford <ojford@gmail.com>

To: Tatsuo Ishii <ishii@postgresql.org>

Cc: tgl@sss.pgh.pa.us, vik@postgresfriends.org, pgsql-hackers@postgresql.org, andrew@tao11.riddles.org.uk, david@fetter.org, krasiyan@gmail.com

Date: 2025-01-21T21:14:55Z

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

Attachments

0004-ignore-nulls.patch (application/octet-stream) patch 0004

On Tue, Jan 21, 2025 at 1:21 AM Tatsuo Ishii <ishii@postgresql.org> wrote:
> It needs lots of work including modifying CREATE FUNCTION
> command. Instead you could add an API to WinObject access functions to
> export ignore_nulls value. Then let each window function check it. If
> the window function should not take IGNORE/RESPECT NULLS option, throw
> an error.

Attached version moves the setting of IGNORE_NULLS to the window
function itself, with the functions that don't allow it erroring out.
This is done with a new api: WinCheckAndInitializeNullTreatment.

Custom functions that don't call this will simply not have the
IGNORE_NULLS option set as this api initializes the option and the
array. As per the previous discussion, it should have correct
formatting and handle the Exclusion clauses correctly.