Message-ID: <753e7734-95d9-45d3-85d9-a53638b1b3dd@vondra.me>
Date: Wed, 25 Mar 2026 15:38:01 +0100
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Subject: Re: Test timings are increasing too fast for cfbot
To: Andres Freund <andres@anarazel.de>, pgsql-hackers@postgresql.org
Cc: Dilip Kumar <dilipbalaut@gmail.com>,
 Jelte Fennema-Nio <postgres@jeltef.nl>, Thomas Munro
 <thomas.munro@gmail.com>, Noah Misch <noah@leadboat.com>
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From: Tomas Vondra <tomas@vondra.me>
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On 3/25/26 04:15, Andres Freund wrote:
> ...
> 
> The slowest test is stats_ext.sql - Not surprising, it does sequential scans
> of tables with ~1000-10000 rows over and over again.  I don't see why it has
> to do that with as many rows as it does.
> 

IIRC we needed to use non-trivial amounts of data to ensure building the
right right type of statistics (e.g. no MCV). But I understand it can be
annoyingly expensive, so I'll try to make it cheaper.

>  ...
> 2) AssertCheckRanges() (only in the brin test, but there a very large portion
>    of the runtime)

True. It is a very comprehensive validation of the ranges, and it was
very useful - particularly during development. But I'll try to make it
more targeted at the stuff actually changed / called less often.

Both changes will require time (so that we don't lose test coverage),
but I assume it's OK if that happens sometime after the feature freeze.


regards

-- 
Tomas Vondra