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From: Fujii Masao <masao.fujii@gmail.com>
Date: Thu, 9 Jul 2026 21:34:50 +0900
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Subject: Re: pgsql: Refactor how some aux processes advertise their ProcNumber
To: Heikki Linnakangas <hlinnaka@iki.fi>
Cc: Thom Brown <thom@linux.com>, pgsql-committers@lists.postgresql.org
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On Thu, Jul 9, 2026 at 9:17=E2=80=AFPM Heikki Linnakangas <hlinnaka@iki.fi>=
 wrote:
> Why is the autovacuum launcher not an aux process? I guess it's because
> it needs to acquire a heavy-weight lock in order to read the list of
> databases.

That seems to be one of the reasons, based on the comment about auxiliary
processes in miscadmin.h:

-------------------------
* Auxiliary processes. These have PGPROC entries, but they are not
* attached to any particular database, and cannot run transactions or
* even take heavyweight locks. There can be only one of each of these
* running at a time, except for IO workers.
-------------------------

Regards,

--=20
Fujii Masao