Message-ID: <4714D817.30701@postgresqlfr.org>
Date: Tue, 16 Oct 2007 17:26:15 +0200
From: =?ISO-8859-1?Q?St=E9phane_Schildknecht?=
	<stephane.schildknecht@postgresqlfr.org>
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To: Tom Lane <tgl@sss.pgh.pa.us>
CC: "pgsql-performance@postgresql.org" <pgsql-performance@postgresql.org>
Subject: Re: Vacuum goes worse
References: <47147AD8.9010704@postgresqlfr.org>
	<15640.1192544768@sss.pgh.pa.us>
In-Reply-To: <15640.1192544768@sss.pgh.pa.us>
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Tom Lane a écrit :
> =?ISO-8859-1?Q?St=E9phane_Schildknecht?= <stephane.schildknecht@postgresqlfr.org> writes:
>   
>> For some times, we have a vacuuming process on a specific table that
>> goes slower and slower. In fact, it took some 3 minutes a month ago, and
>> now it take almost 20 minutes. But, if one day it take so many time, it
>> is possible that on the day after it will only take 4 minutes...
>>     
>
>   
>> I know the table in concern had 450000 tuples two months ago and now has
>> more than 700000 tuples in it.
>>     
>
> The real question is how often do rows get updated?  I suspect you
> probably need to vacuum this table more than once a day.
>
>   

To be honest, I suspect it too. But, I have been told by people using
that database they can't do vacuum more frequently than once in a day as
it increases the time to achieve concurrent operations.
That's also why they don't want to hear about autovacuum.

And finally that's why I'm looking for everything I can monitor to
obtain information to convince them they're wrong and I'm right ;-)

That's also why I am so disappointed vacuum doesn't give me these 4
hints lines.

Regards,

-- 
Stéphane SCHILDKNECHT
Président de PostgreSQLFr
http://www.postgresqlfr.org