Date: Wed, 20 Jun 2007 13:57:58 -0400
From: Alvaro Herrera <alvherre@commandprompt.com>
To: Karl Wright <kwright@metacarta.com>
Cc: Francisco Reyes <lists@stringsutils.com>, Tom Lane <tgl@sss.pgh.pa.us>,
	pgsql-performance@postgresql.org
Subject: Re: Performance query about large tables, lots of concurrent access
Message-ID: <20070620175758.GP30369@alvh.no-ip.org>
References: <14291.1182221811@sss.pgh.pa.us> <4677B831.8060704@metacarta.com>
	<4677D298.2010109@metacarta.com>
	<20070619132643.GC4265@alvh.no-ip.org>
	<4677DC06.3000300@metacarta.com>
	<20070619134637.GG4265@alvh.no-ip.org>
	<cone.1182267949.154012.90929.5001@35st.simplicato.com>
	<467963A8.2060703@metacarta.com>
	<20070620175300.GN30369@alvh.no-ip.org>
	<46796A08.8080601@metacarta.com>
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Karl Wright wrote:
> Alvaro Herrera wrote:
> >Karl Wright wrote:
> >
> >>(b) the performance of individual queries had already degraded 
> >>significantly in the same manner as what I'd seen before.
> >
> >You didn't answer whether you had smaller, more frequently updated
> >tables that need more vacuuming.  This comment makes me think you do.  I
> >think what you should be looking at is whether you can forget vacuuming
> >the whole database in one go, and make it more granular.
> 
> I am afraid that I did answer this.  My largest tables are the ones 
> continually being updated.  The smaller ones are updated only infrequently.

Can you afford to vacuum them in parallel?

-- 
Alvaro Herrera                  http://www.amazon.com/gp/registry/5ZYLFMCVHXC
"Java is clearly an example of money oriented programming"  (A. Stepanov)