Date: Thu, 9 Oct 2014 15:00:25 -0300
From: Alvaro Herrera <alvherre@2ndquadrant.com>
To: jim_yates <pg@wg5jim.net>
Cc: pgsql-sql@postgresql.org
Subject: Re: could not access status of transaction pg_multixact issue
Message-ID: <20141009180022.GE7043@eldon.alvh.no-ip.org>
References: <1412791213607-5822248.post@n5.nabble.com>
 <20141008185538.GY7043@eldon.alvh.no-ip.org>
 <1412797415000-5822268.post@n5.nabble.com>
 <20141008205416.GZ7043@eldon.alvh.no-ip.org>
 <1412863620263-5822376.post@n5.nabble.com>
 <5436A34C.8090306@aklaver.com>
 <20141009151229.GD7043@eldon.alvh.no-ip.org>
 <1412874160409-5822399.post@n5.nabble.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <1412874160409-5822399.post@n5.nabble.com>
User-Agent: Mutt/1.5.21 (2010-09-15)
Precedence: bulk
Sender: pgsql-sql-owner@postgresql.org

jim_yates wrote:
> Alvaro Herrera-9 wrote
> > 
> > There must have been some confusion somewhere; certainly you shouldn't
> > be subtracting anything.  The subtraction was just suggested as a way to
> > determine the age.  The value to update pg_database.datminmxid to is the
> > oldest one of all the relminmxid in pg_class; so if you have 8376 as the
> > minimum value there, that's what you set pg_database.datminmxid to.  Not
> > the 21973 value.
> > 
> >  update pg_database set datminmxid='8376' where datname='production-copy';
> 
> Ok, I'm still confused.  Is the value to use the Max value of relminmxid
> from pg_class or the value of NextMultiXactId from pg_controldump?   Or are
> these the same thing?

You need to *minimum* of all the values in relminmxid (excluding those
that are zero).

The pg_controldata value is a mechanism to determine which value is
minimum -- when there's been wraparound, the minimum might be "smaller
than zero", i.e. something like 4 thousand millions.  I doubt this is
your case though.

-- 
Álvaro Herrera                http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services


-- 
Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-sql