Message-ID: <c37600b41fec9d87f4a83344acf9623b47c5b2c5.camel@cybertec.at>
Subject: Re: pg_upgradecluster and synchronous replication
From: Laurenz Albe <laurenz.albe@cybertec.at>
To: Christoph Berg <myon@debian.org>
Cc: pgsql-pkg-debian@lists.postgresql.org
Date: Thu, 15 Jan 2026 05:40:26 +0100
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On Wed, 2026-01-14 at 20:54 +0100, I wrote:
> On Wed, 2026-01-14 at 20:39 +0100, Christoph Berg wrote:
> >=20
> > Maybe we should instead change the analyze hook script to do that
> > internally? Setting PGOPTIONS should be enough:
> >=20
> > =C2=A0=C2=A0=C2=A0 PGOPTIONS=3D"-csynchronous_commit=3Dlocal"
> >=20
> >=20
> > There is already some code in pg_upgradecluster that works around
> > black magic problems:
> >=20
> > =C2=A0=C2=A0=C2=A0 # ensure we can upgrade DBs with default read-only t=
ransactions
> > =C2=A0=C2=A0=C2=A0 $ENV{PGOPTIONS} .=3D " -cdefault_transaction_read_on=
ly=3Doff";
> >=20
> > This would just add one more wart of that kind.
>=20
> That looks like a better way to do it, I agree.
>=20
>=20
> at makes me wonder.  I don't think that it is a great idea to start the c=
luster for
> production with "synchronous_commit" set to a non-standard value.  That w=
ould mask the
> problem initially, but whenever the cluster is restarted, the parameter i=
s back to its
> original value, and suddenly things will stop working.

Forget that: I missed that with PGOPTIONS, the setting is only changed for
the database session that performs the ANALYZE, not for the entire server
runtime.  Yes, I think that is the proper solution!

Yours,
Laurenz Albe