| From: | Michael Paquier <michael(at)paquier(dot)xyz> |
|---|---|
| To: | Bertrand Drouvot <bertranddrouvot(dot)pg(at)gmail(dot)com> |
| Cc: | shihao zhong <zhong950419(at)gmail(dot)com>, Jim Jones <jim(dot)jones(at)uni-muenster(dot)de>, pgsql-hackers <pgsql-hackers(at)lists(dot)postgresql(dot)org> |
| Subject: | Re: Add a permission check to pg_stat_get_backend_subxact() |
| Date: | 2026-09-22 11:23:54 |
| Message-ID: | arJlSpeSs8yPKipu@paquier.xyz |
| Views: | Whole Thread | Raw Message | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
On Tue, Sep 22, 2026 at 10:03:10AM +0000, Bertrand Drouvot wrote:
> I'm not sure the user ID alone is enough though: if B reuses A's ProcNumber,
> pg_stat_get_backend_wal(B_pid) could still return A's cached statistics when
> the caller is allowed to see A's data.
>
> I'd keep the PID check from 0002 as well. A generation would be more robust
> against PID reuse, as done for example for AIO handles, but introducing a
> backend generation seems like too much for this case.
>
> So storing both seems like the simplest approach: the user ID for the ACL
> check and the PID for matching the statistics to the requested backend.
The PID would also act as a kind of weaker generation number, slightly
weaker but simpler. So that works here. Perhaps you would like to
give it a shot?
--
Michael
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Pavel Luzanov | 2026-09-22 11:26:43 | Re: Several issues with postgres_fdw stats import |
| Previous Message | Nisha Moond | 2026-09-22 11:01:10 | Re: Crashes on a partition whose concurrent detach never finished |