Message-ID: <58a6e18b112b4cd8bd9ab66d3f0ff5e77ada8799.camel@cybertec.at>
Subject: Re: Requiring recovery.signal or standby.signal when recovering
 with a backup_label
From: Laurenz Albe <laurenz.albe@cybertec.at>
To: Michael Paquier <michael@paquier.xyz>, David Steele <david@pgmasters.net>
Cc: Kyotaro Horiguchi <horikyota.ntt@gmail.com>, 
 pgsql-hackers@lists.postgresql.org, zxwsbg12138@gmail.com,
 david.zhang@highgo.ca
Date: Mon, 16 Oct 2023 17:48:43 +0200
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On Mon, 2023-10-16 at 14:54 +0900, Michael Paquier wrote:
> Thanks for the review.=C2=A0 Yes, I am wondering if other people would
> chime in here.=C2=A0 It doesn't feel like this has gathered enough
> opinions.

I don't have strong feelings either way.  If you have backup_label
but no signal file, starting PostgreSQL may succeed (if the WAL
with the checkpoint happens to be in pg_wal) or it may fail with
an error message.  There is no danger of causing damage unless you
remove backup_label, right?

I cannot think of a use case where you use such a configuration on
purpose, and the current error message is more crypric than a plain
"you must have a signal file to start from a backup", so perhaps
your patch is a good idea.

Yours,
Laurenz Albe