From: Josh Berkus <josh@agliodbs.com>
To: pgsql-performance@postgresql.org
Subject: Re: Where does data in pg_stat_user_tables come from?
Date: Thu, 16 Sep 2010 11:39:22 -0700
Message-ID: <4C92645A.1040208@agliodbs.com> (raw)
In-Reply-To: <1284436337-sup-9871@alvh.no-ip.org>
References: <4C8EAE5E.70201@agliodbs.com>
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<1284436337-sup-9871@alvh.no-ip.org>
> It's been pure nonsense in this thread. Please show an example of
> what's not working.
1) Init a postgresql 8.3 with autovacuum disabled.
2) Load a backup of a database into that PostgreSQL.
3) Check pg_stat_user_tables. n_live_tup for all tables will be 0.
4) VACUUM ANALYZE the whole database.
5) n_live_tup will *still* be 0. Whereas reltuples in pg_class will be
reasonable accurate.
> Um ... it updates the last_autovacuum and last_autoanalyze columns,
> but the others are not its responsibility.
Right. I'm contending that ANALYZE *should* update those columns.
Current behavior is unintuitive and makes the stats in
pg_stat_user_tables almost useless, since you can never get even
approximately a coherent snapshot of data for all tables.
--
-- Josh Berkus
PostgreSQL Experts Inc.
http://www.pgexperts.com
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To: pgsql-performance@postgresql.org
Cc: josh@agliodbs.com
Subject: Re: Where does data in pg_stat_user_tables come from?
In-Reply-To: <4C92645A.1040208@agliodbs.com>
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