Reply-To: <gnanam@zoniac.com>
From: "Gnanakumar" <gnanam@zoniac.com>
To: "'Alvaro Herrera'" <alvherre@commandprompt.com>
Cc: "'pgsql-admin'" <pgsql-admin@postgresql.org>
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	<1281637751-sup-2462@alvh.no-ip.org>
In-Reply-To: <1281637751-sup-2462@alvh.no-ip.org>
Subject: Re: Autovacuum daemon internal handling
Date: Fri, 13 Aug 2010 18:36:21 +0530
Organization: Zoniac Software Private Limited
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Thanks for the update.

> The main difference is that 8.2 has only one process working at a =
time,
> whereas in 8.3 and later there can be several.  When there's only one
> process, the only way for it to process several databases is
> sequentially; the naptime is how long to sleep between each item in =
the
> list.

> In 8.3, naptime is the time that lapses between two processes =
starting,
> while respecting the limit of maximum processes that you configured in
> max_workers.  So if the time is already up but all processes are busy
> elsewhere, the next autovacuum will have to wait until one of those
> finishes.

> Since there are multiple processes, you can configure more so that all
> tables can be vacuumed in time.

>> Is there any way to find out the start time of "last_autovaccum" =
and/or 'last_autoanalyze" for a given table in 8.2.3?  So that I can =
isolate the tables that are taking too long time to complete vacuum =
and/or analyze and I can perform them externally if need.

> No, I don't think there is in 8.2, unless you crank the debug level =
down
> to DEBUG2 which means log a lot of stuff (probably too noisy to be
> useful).