Re: Regression failures after changing PostgreSQL blocksize - Mailing list pgsql-hackers

From Álvaro Herrera
Subject Re: Regression failures after changing PostgreSQL blocksize
Date
Msg-id 202602121948.62bdwwea4so5@alvherre.pgsql
Whole thread Raw
In response to Re: Regression failures after changing PostgreSQL blocksize  (Yasir <yasir.hussain.shah@gmail.com>)
List pgsql-hackers
On 2026-Feb-13, Yasir wrote:

> can we add alternative test output files for the changes caused by
> different block sizes? E.g: the attached poc patch. Whether such an
> approach would be acceptable?

Absolutely not.  For starters, how did you verify that these new files
are correct?  Second, I imagine this patch is just for this one file,
but that there numerous other files that would have to be patched,
right?  If so, how many, and how extensive are the changes?

If you wanted to propose some surgical interventions to the affected
files that made the tests pass for other page sizes, then perhaps that
could be entertained.  Looking at the files you sent, I see that from
the original to _2.out there are two plan changes (hash aggregates
become group aggregates); then from _2.out to _1.out a single query
changes from indexscan to bitmap scan; and lastly, from the original to
_3.out there are some seqscans that become index scans.  So if you were
to propose a patch that adds a SET call to disable some plan type just
before one query, and RESET it immediately after that query; and with
such a change the test runs unchanged across all block sizes, then maybe
that would be something we could consider.  (However, getting a
committer to review such changes might be a hard sell also -- no
promises!)

Also, if you find that you need too many changes of this kind in order
to make this work, then that's probably not going to fly either.

> Which other compile time options are expected to cause test failures?

You're welcome to experiment and let us know what you find.

-- 
Álvaro Herrera        Breisgau, Deutschland  —  https://www.EnterpriseDB.com/



pgsql-hackers by date:

Previous
From: Nathan Bossart
Date:
Subject: Re: pg_upgrade: transfer pg_largeobject_metadata's files when possible
Next
From: Andres Freund
Date:
Subject: Re: Changing shared_buffers without restart