Date: Wed, 23 Apr 2014 14:47:16 -0400
From: Bruce Momjian <bruce@momjian.us>
To: Alvaro Herrera <alvherre@2ndquadrant.com>
Cc: Andres Freund <andres@2ndquadrant.com>,
 Stephen Frost <sfrost@snowman.net>, pgsql-hackers@postgresql.org
Subject: Re: MultiXactId error after upgrade to 9.3.4
Message-ID: <20140423184716.GA22722@momjian.us>
References: <20140330040029.GY4582@tamriel.snowman.net>
 <20140330141135.GA4582@tamriel.snowman.net>
 <20140330185349.GD4582@tamriel.snowman.net>
 <20140331115452.GT9567@eldon.alvh.no-ip.org>
 <20140331115713.GA18358@alap3.anarazel.de>
 <20140423180102.GP25695@eldon.alvh.no-ip.org>
 <20140423182804.GA21458@momjian.us>
 <20140423184214.GQ25695@eldon.alvh.no-ip.org>
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On Wed, Apr 23, 2014 at 03:42:14PM -0300, Alvaro Herrera wrote:
> > > I still don't know under what circumstances this situation could arise.
> > > This seems most strange to me.  I would wonder about this to be just
> > > papering over a different bug elsewhere, except that we know this tuple
> > > comes from a pg_upgraded table and so I think the only real solution is
> > > to cope.
> > 
> > Shouldn't we log something at least if we are unsure of the cause?
> 
> I don't know.  Is it possible that XMAX_IS_MULTI got set because of
> cosmic rays?  At this point that's the only explanation that makes sense
> to me.  And I'm not sure what to do about this until we know more --
> more user reports of this problem, for instance.
> 
> I don't see any reasonable way to distinguish this particular kind of
> multixact-out-of-bounds situation from any other, so not sure what else
> to log either (you can see that we already emit an error message.)

I guess I am lost then.  I thought it supressed the error.  What does
the patch do?

-- 
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

  + Everyone has their own god. +


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