Message-ID: <4CDAE7AE.3040105@iii.com>
Date: Wed, 10 Nov 2010 10:42:54 -0800
From: Dinesh Bhandary <dbhandary@iii.com>
Reply-To: dbhandary@iii.com
Organization: Innovative Interfaces
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To: pgsql-admin@postgresql.org
Subject: auto vacuum
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Hi All -

We run both postgres 8.2.3 and 8.4.1  in unix environment. We have auto 
vacuum configured and I am trying to find out its effectiveness. Here 
are a couple of questions:

1) I'm running a query that compares actual table count with the pg_stat 
table count ( pg_stat_user_tables.n_live_tup) to make sure there is not 
a huge difference between two. If the difference is small or within the 
analyze threshold I know vacuum analyze is running and doing its work. I 
am seeing that truncate does not trigger autovacuum analayze like delete 
does and pg_stat_user_tables.n_live_tup is not updated ( please correct 
me If I am wrong). Does it mean I have to run analyze manually whenever 
I truncate a table or system has a way of tracking.

2) In postgres 8.2 pg_stat_user_tables.n_live_tup field is missing. Is 
there a way to get table counts as the system sees it in 8.2?

Thanks.

Dinesh