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From: Robert Haas <robertmhaas@gmail.com>
Date: Wed, 5 Apr 2023 15:58:28 -0400
Message-ID: <CA+TgmoYshCZF4a0k4R3eOwn08xXqSdfmPxzGxS0RKBVmKAByGg@mail.gmail.com>
Subject: Re: Should vacuum process config file reload more often
To: Melanie Plageman <melanieplageman@gmail.com>
Cc: Daniel Gustafsson <daniel@yesql.se>, Andres Freund <andres@anarazel.de>, Tom Lane <tgl@sss.pgh.pa.us>, 
	Masahiko Sawada <sawada.mshk@gmail.com>, Kyotaro Horiguchi <horikyota.ntt@gmail.com>, 
	PostgreSQL Hackers <pgsql-hackers@postgresql.org>, Amit Kapila <amit.kapila16@gmail.com>
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On Wed, Apr 5, 2023 at 3:44=E2=80=AFPM Melanie Plageman
<melanieplageman@gmail.com> wrote:
> VacuumUpdateCosts() also calls AutoVacuumUpdateCostLimit(), so this will
> happen if a config reload is pending the next time vacuum_delay_point()
> is called (which is pretty often -- roughly once per block vacuumed but
> definitely more than once per table).
>
> Relevant code is at the top of vacuum_delay_point():
>
>     if (ConfigReloadPending && IsAutoVacuumWorkerProcess())
>     {
>         ConfigReloadPending =3D false;
>         ProcessConfigFile(PGC_SIGHUP);
>         VacuumUpdateCosts();
>     }

Yeah, that all makes sense, and I did see that logic, but I'm
struggling to reconcile it with what that comment says.

Maybe I'm just confused about what that comment is trying to explain.

--=20
Robert Haas
EDB: http://www.enterprisedb.com