Horton

Re: BUG with accessing to temporary tables of other sessions still exists

Daniil Davydov <3danissimo@gmail.com>

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From: Daniil Davydov <3danissimo@gmail.com>
To: Jim Jones <jim.jones@uni-muenster.de>
Cc: PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2026-06-03T15:51:34Z
Lists: pgsql-hackers

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Hi,

On Wed, Jun 3, 2026 at 10:20 PM Jim Jones <jim.jones@uni-muenster.de> wrote:
>
> Session 1 here does not create a temporary table (most likely a copy &
> paste error), but I could reproduce this error as you suggested:
>

Sorry, I wrote it manually and forgot to specify "TEMP". It is implied here,
of course.

>
> At a first glance the check seems reasonable. One tiny wording nit: the
> comment in ExtendBufferedRelLocal says "... covering any attempt to
> extend local relation.", but to avoid any confusing with the meaning of
> RELATION_IS_LOCAL I'd argue that "covering any attempt to extend a
> temporary relation" would be slightly clearer.
>

Thanks for looking into this! I agree with your comment.

Please, see v2 patch with fixed comment.

--
Best regards,
Daniil Davydov

Commits

  1. Prevent access to other sessions' empty temp tables

  2. Add tests for cross-session temp table access

  3. Prevent access to other sessions' temp tables