Feedback-ID: i0fe9450f:Fastmail
Date: Fri, 8 May 2026 15:19:32 +0900
From: Michael Paquier <michael@paquier.xyz>
To: Alexander Korotkov <aekorotkov@gmail.com>
Cc: Daniil Davydov <3danissimo@gmail.com>,
	Jim Jones <jim.jones@uni-muenster.de>,
	Soumya S Murali <soumyamurali.work@gmail.com>,
	Tom Lane <tgl@sss.pgh.pa.us>, Stepan Neretin <slpmcf@gmail.com>,
	PostgreSQL Hackers <pgsql-hackers@postgresql.org>,
	Mohamed Ali <moali.pg@gmail.com>,
	Nazneen Jafri <jafrinazneen@gmail.com>,
	Shawn McCoy <shawn.the.mccoy@gmail.com>
Subject: Re: Fix bug with accessing to temporary tables of other sessions
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On Thu, May 07, 2026 at 11:04:16AM +0300, Alexander Korotkov wrote:
> Let me do a quick summary:
>  * Our buffer manager is not capable for reading temp tables of other ses=
sions.
>  * This was covered by explicit checks, but broken since b7b0f3f27241
> introduced alternative code path for reading tables.
>  * This doesn't apply to DROP TABLE.  DROP TABLE is a conscious
> exclusion and the only operation we can do correctly for other
> session' temp tables.  There is an explicit exclusion in the code to
> skip the attempt to cleanup buffers of other session' temp tables.
>  * This patchset consists of tests (0001) for various operations with
> other session's temp tables including buggy behavior, and the fix
> (0002) including changes for tests.
>=20
> Thus, I don't see the reason why this shouldn't be committed and
> backpatched to PG17 (first release containing b7b0f3f27241).
> Opinions?  Michael?

Hmm.  I don't have any counter-arguments against a backpatch based on
your argument related to b7b0f3f27241.  Thanks for reorganizing the
patch set so as the tests happen first, and the changes in the code
become second.

If you wish me to look at this patch set in details, I may be able to
do so around the beginning of next week.  I'm not sure that there is a
strong urgency in tackling this issue for this minor release, this
could wait a bit more..
--
Michael

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