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From: Amit Kapila <amit.kapila16@gmail.com>
Date: Fri, 20 Jun 2025 08:25:34 +0530
Message-ID: 
 <CAA4eK1JnPmVW+yxJSxxjU+-93x4TojSZhK9v1ZavH8uCe_5Arw@mail.gmail.com>
Subject: Re: Slot's restart_lsn may point to removed WAL segment after hard
 restart unexpectedly
To: Alexander Korotkov <aekorotkov@gmail.com>
Cc: Vitaly Davydov <v.davydov@postgrespro.ru>,
 vignesh C <vignesh21@gmail.com>,
	"Hayato Kuroda (Fujitsu)" <kuroda.hayato@fujitsu.com>,
 Tom Lane <tgl@sss.pgh.pa.us>,
	Alexander Lakhin <exclusion@gmail.com>,
 pgsql-hackers <pgsql-hackers@postgresql.org>,
	Masahiko Sawada <sawada.mshk@gmail.com>, "tomas@vondra.me" <tomas@vondra.me>
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On Fri, Jun 20, 2025 at 5:48=E2=80=AFAM Alexander Korotkov <aekorotkov@gmai=
l.com> wrote:
>
> >
> > If what I said above is correct, then the following part of the commit
> > message will be incorrect:
> > "As stated in the ReplicationSlotReserveWal() comment, this is not
> > always true. Additionally, this issue has been spotted by some
> > buildfarm
> > members."
>
> I agree, this comment needs improvement in terms of clarity.
>
> Meanwhile I've pushed the patch for TAP tests, which I think didn't
> get any objections.
>

Sounds reasonable. As per analysis till now, it seems removal of new
assert is correct and we just need to figure out the reason in all
failure cases as to why the physical slot's restart_lsn goes backward,
and then add a comment somewhere to ensure that we don't repeat a
similar mistake in the future.

--=20
With Regards,
Amit Kapila.