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In-Reply-To: 
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From: Alexander Korotkov <aekorotkov@gmail.com>
Date: Fri, 18 Jul 2025 14:41:31 +0300
Message-ID: 
 <CAPpHfdsO6xnGJmVT843W0A7RAv8owMQVSs9Bgj7V2uVyzcopLQ@mail.gmail.com>
Subject: Re: Slot's restart_lsn may point to removed WAL segment after hard
 restart unexpectedly
To: Amit Kapila <amit.kapila16@gmail.com>
Cc: "Hayato Kuroda (Fujitsu)" <kuroda.hayato@fujitsu.com>,
 Vitaly Davydov <v.davydov@postgrespro.ru>,
	vignesh C <vignesh21@gmail.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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 <https://www.postgresql.org/message-id/CAPpHfdsO6xnGJmVT843W0A7RAv8owMQVSs9Bgj7V2uVyzcopLQ%40mail.gmail.com>
Precedence: bulk

On Fri, Jul 18, 2025 at 1:48=E2=80=AFPM Amit Kapila <amit.kapila16@gmail.co=
m> wrote:
> On Fri, Jul 18, 2025 at 4:15=E2=80=AFPM Alexander Korotkov <aekorotkov@gm=
ail.com> wrote:
> >
> > On Sun, Jun 29, 2025 at 9:22=E2=80=AFAM Hayato Kuroda (Fujitsu)
> > <kuroda.hayato@fujitsu.com> wrote:
> > > Thanks everyone who are working on the bug. IIUC the remained task is
> > > to add code comments for avoiding the same mistake again described he=
re:
> > >
> > > > Sounds reasonable. As per analysis till now, it seems removal of ne=
w
> > > > 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 backwa=
rd,
> > > > and then add a comment somewhere to ensure that we don't repeat a
> > > > similar mistake in the future.
> > >
> > > I've wrote a draft for that. How do you think?
> >
> > Looks good to me.  I'm going to push this if no objections.
> >
>
> As discussed earlier, it is a good idea to add comments in this area.
> But as this is for pre-existing cases, won't it be better to start a
> new thread explaining the cases and a patch? We may get feedback from
> others as well.

OK, done.

https://www.postgresql.org/message-id/CAPpHfdvuyMrUg0Vs5jPfwLOo1M9B-GP5j_My=
9URnBX0B%3DnrHKw%40mail.gmail.com

------
Regards,
Alexander Korotkov
Supabase