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Re: Indexes on expressions with multiple columns and operators

Ranier Vilela <ranier.vf@gmail.com>

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From: Ranier Vilela <ranier.vf@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Frédéric Yhuel <frederic.yhuel@dalibo.com>, "pgsql-performance@lists.postgresql.org" <pgsql-performance@lists.postgresql.org>, Jehan-Guillaume de Rorthais <jgdr@dalibo.com>, Christophe Courtois <christophe.courtois@dalibo.com>, Laurenz Albe <laurenz.albe@cybertec.at>
Date: 2025-09-18T16:48:08Z
Lists: pgsql-performance 
Em qui., 18 de set. de 2025 às 13:40, Tom Lane <tgl@sss.pgh.pa.us> escreveu:

> I wrote:
> > Sigh ... so the answer is this used to work (since commit 39df0f150)
> > and then I carelessly broke it in commit a391ff3c3.  If you try this
> > test case in versions 9.5..11 you get a spot-on rowcount estimate.
> > Serves me right for not having a test case I guess, but I'm astonished
> > that nobody complained sooner.
>
> The attached fixes things so it works like it did pre-a391ff3c3.
>
> I spent some time trying to devise a test case, and was reminded
> of why I didn't have one before: it's hard to make a case that
> will be robust enough to not show diffs in the buildfarm.
> I'll keep thinking about that though.
>
One question, make difference return -1.0 (float point notation)?
If not, static analyzers will have less work.

best regards,
Ranier Vilela

Commits

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

  1. Re-allow using statistics for bool-valued functions in WHERE.

  2. Build out the planner support function infrastructure.

  3. Allow planner to use expression-index stats for function calls in WHERE.