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

From: Oliver Ford <ojford(at)gmail(dot)com>
To: Tatsuo Ishii <ishii(at)sraoss(dot)co(dot)jp>
Cc: Pg Hackers <pgsql-hackers(at)postgresql(dot)org>, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, vik(at)postgresfriends(dot)org, andrew(at)tao11(dot)riddles(dot)org(dot)uk, David Fetter <david(at)fetter(dot)org>, Krasiyan Andreev <krasiyan(at)gmail(dot)com>
Subject: Re: Add RESPECT/IGNORE NULLS and FROM FIRST/LAST options
Date: 2024-09-07 20:25:28
Message-ID: CAGMVOdtHqnD+3euGGj6rU9TjG04KoW_18g4Dy=04s5MzoTC78w@mail.gmail.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

On Sat, May 6, 2023 at 9:41 AM Oliver Ford <ojford(at)gmail(dot)com> wrote:
>
>
>
> On Sat, 6 May 2023, 04:57 Tatsuo Ishii, <ishii(at)sraoss(dot)co(dot)jp> wrote:
>>
>> Attached is the patch to implement this (on top of your patch).
>>
>> test=# SELECT row_number() RESPECT NULLS OVER () FROM (SELECT 1) AS s;
>> ERROR: window function row_number cannot have RESPECT NULLS or IGNORE NULLS
>
>
> The last time this was discussed (https://www.postgresql.org/message-id/1037735.1610402426%40sss.pgh.pa.us) it was suggested to make the feature generalizable, beyond what the standard says it should be limited to.
>
> With it generalizable, there would need to be extra checks for custom functions, such as if they allow multiple column arguments (which I'll add in v2 of the patch if the design's accepted).
>
> So I think we need a consensus on whether to stick to limiting it to several specific functions, or making it generalized yet agreeing the rules to limit it (such as no agg functions, and no functions with multiple column arguments).

Reviving this thread, I've attached a rebased patch with code, docs,
and tests and added it to November commitfest.

Attachment Content-Type Size
0001-add-ignore_nulls.patch application/octet-stream 39.1 KB

In response to

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message Tom Lane 2024-09-07 20:45:34 Re: pgstattuple: fix free space calculation
Previous Message Tom Lane 2024-09-07 20:18:42 Re: Undocumented functions