From: Tom Lane <tgl@sss.pgh.pa.us>
To: Arctic Toucan <arctic_toucan@hotmail.com>
Cc: pgsql-admin@postgresql.org
Subject: Re: How can I avoid Frozenxid wraparound on failover to a standby(PITR) database?
Date: Fri, 05 Sep 2008 12:52:17 -0400
Message-ID: <26690.1220633537@sss.pgh.pa.us> (raw)
In-Reply-To: <BAY126-W41BCC3E747431387BDB0999C580@phx.gbl>
References: <BAY126-W41BCC3E747431387BDB0999C580@phx.gbl>
Arctic Toucan <arctic_toucan@hotmail.com> writes:
> I next started looking at the age(refrozenxid) of the tables in my DB, and was surprised to see that over 4000 of the 5000 tables in this DB had an age over 2Billion. So thats 4000 tables representing over a terabyte of data that need to be vacuumed! I am now vacuuming those tables one at a time, which is taking a long time(This is a scripted process). So there is no way I could have vacuumed the tables quickly enough even given a warning of impending XID wraparound.
> Looking through the support mailing lists(Bugs) I see some discussion about the frozenxid updates on the master not being propogated to the slave through the WAL logs, and comments from Tom, Alvaro and Heikki suggesting that they were looking into a solution for PG 8.3 and needed a way around the problem in PG 8.2.
Hmm ... that did get fixed in 8.2
http://archives.postgresql.org/pgsql-committers/2006-11/msg00026.php
so I'm a bit confused about what happened here. What were your
autovacuum settings on the old master? Particularly
autovacuum_freeze_max_age?
regards, tom lane
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To: pgsql-admin@postgresql.org
Cc: tgl@sss.pgh.pa.us, arctic_toucan@hotmail.com
Subject: Re: How can I avoid Frozenxid wraparound on failover to a standby(PITR) database?
In-Reply-To: <26690.1220633537@sss.pgh.pa.us>
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