Re: Fix bug with accessing to temporary tables of other sessions

Hi all,

Thank you for reviewing the patch and for the detailed explanation.

On Tue, Apr 21, 2026 at 1:37 AM Alexander Korotkov <aekorotkov(at)gmail(dot)com> wrote:
>
> Hi!
>
> I've checked the thread. Thanks to all the participants for their
> work. I think there is a general agreement on the design.
>
> On Thu, Apr 16, 2026 at 9:41 AM Soumya S Murali
> <soumyamurali(dot)work(at)gmail(dot)com> wrote:
> > Thank you for the guidance and the updated patch.
> >
> > On Mon, Apr 13, 2026 at 7:26 PM Jim Jones <jim(dot)jones(at)uni-muenster(dot)de> wrote:
> > >
> > > Hi
> > >
> > > On 13/04/2026 14:40, Soumya S Murali wrote:
> > > > Please let me know if there are additional scenarios I should
> > > > validate. Looking forward to more feedback.
> > >
> > > Thanks for testing it. You can take a look at
> > > 012_temp_obj_multisession.pl and check if we missed any path.
> > >
> > > Due to changes introduced in b2a17ba7a5d the patch was no longer
> > > applying. See rebased v18 attached.
> > >
> >
> >
> > I tested the rebased v18 patch on a clean tree and verified that it
> > applies cleanly and behaves consistently with previous results.
> > Cross-session access is correctly blocked with: ERROR: cannot access
> > temporary relations of other sessions
> > Index scan paths are also properly restricted, and same-session access
> > continues to work as expected.
> > The updated test changes look good. Everything works as expected, +1
> > from my side.
>
> I see the patch changes the error wording. Previously the error was
> "cannot access temporary tables of other sessions", but we change it
> to "cannot access temporary relation of other sessions". I see the
> intention here: we trigger an error while accessing some relation (not
> necessarily a table) then we should reflect this directly to the error
> message. However, old message is already here for quite a while and
> translated into many languages. Also, is old message incorrect? We
> trigger an error on buffer access. That is, we trigger an error only
> for relation with a storage: table, index, sequence or matview.
> Matview can't be temporary. Also, if you access an index with a
> query, that means you're querying its table. But sequence can be
> temporary and it can be not directly associated with a table. So,
> yes, new error message is more correct. But I would prefer to make it
> a separate patch, and replace all the occurrences including contrib.
>

This makes sense. While the new wording is indeed more precise, I
agree that changing an existing error message, especially one that has
been present for a long time and is already translated, should be
handled
separately from the bug fix. Keeping the current message for this
patch and addressing wording improvements in a dedicated follow-up
patch sounds like the right approach.
Thanks for pointing this out.

Regards,
Soumya