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Subject: Re: Should vacuum process config file reload more often
From: Daniel Gustafsson <daniel@yesql.se>
In-Reply-To: <CAAKRu_Znk6WCCQqEw8hv3+X1Fm8gG0x4KKRAkKmO2JOcA-77-g@mail.gmail.com>
Date: Fri, 7 Apr 2023 01:08:09 +0200
Cc: Robert Haas <robertmhaas@gmail.com>,
 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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To: Melanie Plageman <melanieplageman@gmail.com>
Archived-At: <https://www.postgresql.org/message-id/2B703533-102A-47E5-A4F7-C6A68C09BB27%40yesql.se>
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> On 7 Apr 2023, at 00:12, Melanie Plageman <melanieplageman@gmail.com> =
wrote:
>=20
> On Thu, Apr 6, 2023 at 5:45=E2=80=AFPM Daniel Gustafsson =
<daniel@yesql.se> wrote:
>>=20
>>> On 6 Apr 2023, at 23:06, Melanie Plageman =
<melanieplageman@gmail.com> wrote:
>>=20
>>> Autovacuum workers, at the end of VacuumUpdateCosts(), check if cost
>>> limit or cost delay have been changed. If they have, they assert =
that
>>> they don't already hold the AutovacuumLock, take it in shared mode, =
and
>>> do the logging.
>>=20
>> Another idea would be to copy the values to local temp variables =
while holding
>> the lock, and release the lock before calling elog() to avoid holding =
the lock
>> over potential IO.
>=20
> Good idea. I've done this in attached v19.
> Also I looked through the docs and everything still looks correct for
> balancing algo.

I had another read-through and test-through of this version, and have =
applied
it with some minor changes to comments and whitespace.  Thanks for the =
quick
turnaround times on reviews in this thread!

I opted for keeping the three individual commits, squashing them didn't =
seem
helpful enough to future commitlog readers and no other combination of =
the
three made more sense than what has been in the thread.

--
Daniel Gustafsson