From: Tom Lane <tgl@sss.pgh.pa.us>
To: Andres Freund <andres@anarazel.de>
cc: Peter Geoghegan <pg@bowt.ie>, Heikki Linnakangas <hlinnaka@iki.fi>,
        pgsql-hackers <pgsql-hackers@postgresql.org>,
        Justin Pryzby <pryzby@telsasoft.com>
Subject: Re: prion failed with ERROR: missing chunk number 0 for toast value
 14334 in pg_toast_2619
In-reply-to: <20210516223513.outnhdfibafroqc4@alap3.anarazel.de>
References: <f03ea04a-9b77-e371-9ab9-182cb35db1f9@iki.fi>
 <2472976.1621117273@sss.pgh.pa.us> <2591376.1621196582@sss.pgh.pa.us>
 <CAH2-Wz=Pdfhd0Pc3g6odxkgBP9P6nsp1uaiR0JYRac9fYyYGrQ@mail.gmail.com>
 <2595981.1621203681@sss.pgh.pa.us>
 <20210516223513.outnhdfibafroqc4@alap3.anarazel.de>
Comments: In-reply-to Andres Freund <andres@anarazel.de>
	message dated "Sun, 16 May 2021 15:35:13 -0700"
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-ID: <2601444.1621204973.1@sss.pgh.pa.us>
Date: Sun, 16 May 2021 18:42:53 -0400
Message-ID: <2601445.1621204973@sss.pgh.pa.us>
Archived-At: 
 <https://www.postgresql.org/message-id/2601445.1621204973%40sss.pgh.pa.us>
Precedence: bulk

Andres Freund <andres@anarazel.de> writes:
> On 2021-05-16 18:21:21 -0400, Tom Lane wrote:
>> Hm, yeah.  I'm not sure if transferring the value forward from the
>> old cluster is entirely safe, but if it is, that seems like a
>> promising route to a fix.  (We should still have more sanity checking
>> around the GlobalVis code, though.)

> Why would it not be safe?

I'm just wondering about the catalog tuples set up by pg_upgrade
itself.  If they're all frozen then they probably don't matter to
this, but it might take some thought.

> I think we should remove the heuristic thing from pg_resetwal entirely,
> and error out if next-xid is set to something too far away from oldest
> xid, unless oldexid is also specified.

Seems plausible ...

			regards, tom lane