From: Stephen Frost <sfrost@snowman.net>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Peter Geoghegan <pg@heroku.com>
Cc: Andres Freund <andres@anarazel.de>
Cc: Heikki Linnakangas <hlinnaka@iki.fi>
Cc: Jeff Janes <jeff.janes@gmail.com>
Cc: Dean Rasheed <dean.a.rasheed@gmail.com>
Cc: Bruce Momjian <bruce@momjian.us>
Cc: Pg Hackers <pgsql-hackers@postgresql.org>
Subject: Re: INSERT ... ON CONFLICT UPDATE/IGNORE 4.0
Date: Fri, 8 May 2015 15:16:00 -0400
Message-ID: <20150508191600.GA30322@tamriel.snowman.net> (raw)
In-Reply-To: <18911.1431112384@sss.pgh.pa.us>
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<17473.1431109846@sss.pgh.pa.us>
<20150508183504.GU12950@alap3.anarazel.de>
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* Tom Lane (tgl@sss.pgh.pa.us) wrote:
> I wrote:
> > Peter Geoghegan <pg@heroku.com> writes:
> >> On Fri, May 8, 2015 at 11:59 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> >>> Ooops. But shouldn't that have failed 100% of the time in a CCA build?
> >>> Or is the candidates list fairly noncritical?
>
> >> The candidates list is absolutely critical.
>
> > Oh, I was confusing CCA with RELCACHE_FORCE_RELEASE, which does something
> > a bit different.
>
> Actually, looking closer, the quoted code is simply not broken without
> RELCACHE_FORCE_RELEASE: without that, neither heap_close nor index_close
> will do anything that could cause a cache flush. So while it's certainly
> good pratice to move that lappend_oid call up, it does not explain the
> observed symptoms. We still need some more investigation here.
Couldn't a cache flush request come from another backend? Although this
isn't being run in a parallel group, is it? Maybe a delayed signal that
happens to show up late at just the right time? Dunno if we've ever
actually seen that but the thought occured to me.
Thanks!
Stephen
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To: pgsql-admin@postgresql.org
Cc: sfrost@snowman.net, tgl@sss.pgh.pa.us, pg@heroku.com, andres@anarazel.de, hlinnaka@iki.fi, jeff.janes@gmail.com, dean.a.rasheed@gmail.com, bruce@momjian.us, pgsql-hackers@postgresql.org
Subject: Re: INSERT ... ON CONFLICT UPDATE/IGNORE 4.0
In-Reply-To: <20150508191600.GA30322@tamriel.snowman.net>
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