From: Tom Lane <tgl@sss.pgh.pa.us>
To: Alvaro Herrera <alvherre@alvh.no-ip.org>
Cc: Michael Paquier <michael@paquier.xyz>
Cc: pgsql-hackers@lists.postgresql.org
Subject: Re: Odd, intermittent failure in contrib/pageinspect
Date: Mon, 18 Jan 2021 17:35:00 -0500
Message-ID: <416195.1611009300@sss.pgh.pa.us> (raw)
In-Reply-To: <20210118223019.GA2579@alvherre.pgsql>
References: <20210118223019.GA2579@alvherre.pgsql>
Alvaro Herrera <alvherre@alvh.no-ip.org> writes:
> On 2021-Jan-18, Tom Lane wrote:
>> Searching the buildfarm logs turned up exactly one previous occurrence,
>> also on whelk [2]. So I'm not sure what to make of it. Could the
>> immediately preceding VACUUM FREEZE command have silently skipped this
>> page for some reason? That'd be a bug I should think.
> Hmm, doesn't vacuum skip pages when they are pinned? I don't think
> VACUUM FREEZE would be treated especially -- only "aggressive"
> wraparound would be an exception, IIRC.
Right. If that's the explanation, then adding DISABLE_PAGE_SKIPPING
to the test's VACUUM options should fix it. However, to believe that
theory you have to have some reason to think that some other process
might have the page pinned. What would that be? test1 only has one
small tuple in it, so it doesn't seem credible that autovacuum or
autoanalyze would have fired on it.
[ thinks for a bit... ] Does the checkpointer pin pages it's writing
out? I guess it'd have to ...
regards, tom lane
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-hackers@postgresql.org
Cc: tgl@sss.pgh.pa.us, alvherre@alvh.no-ip.org, michael@paquier.xyz, pgsql-hackers@lists.postgresql.org
Subject: Re: Odd, intermittent failure in contrib/pageinspect
In-Reply-To: <416195.1611009300@sss.pgh.pa.us>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox