Horton

Re: Allow non-superuser to cancel superuser tasks.

Nathan Bossart <nathandbossart@gmail.com>

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From: Nathan Bossart <nathandbossart@gmail.com>
To: Andres Freund <andres@anarazel.de>
Cc: Alexander Kukushkin <cyberdemn@gmail.com>, "Andrey M. Borodin" <x4mmm@yandex-team.ru>, Michael Paquier <michael@paquier.xyz>, Kirill Reshke <reshkekirill@gmail.com>, "Leung, Anthony" <antholeu@amazon.com>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Date: 2024-11-26T21:07:24Z
Lists: pgsql-hackers

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On Tue, Nov 26, 2024 at 12:27:33PM -0500, Andres Freund wrote:
> On 2024-11-22 20:44:34 -0600, Nathan Bossart wrote:
>> D'oh, I missed that ProcNumber could be used as an index for the
>> BackendStatusArray.  Is the attached more like what you are imagining?
> 
> Yes.
> 
> I'd probably add two function header comments:
> 
> 1) explicit caution that this is fetching information not from the snapshot
>    but "live" data
> 2) the return value might be out of date, that the procnumber needs to be
>    valid and that the caller is responsible for permission checking
> 
> I'd also add a comment do the code saying that it's fine to bypass the
> changecount mechanism, because we're reading a single 4 byte integer.

I've attempted to add all these details in v3.

-- 
nathan

Commits

  1. Look up backend type in pg_signal_backend() more cheaply.

  2. Add tap test for pg_signal_autovacuum role

  3. Introduce pg_signal_autovacuum_worker.

  4. Add a slot synchronization function.

  5. Ban role pg_signal_backend from more superuser backend types.