Message-ID: <4BC8A91D.9030709@2ndquadrant.com>
Date: Fri, 16 Apr 2010 14:14:53 -0400
From: Greg Smith <greg@2ndquadrant.com>
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To: Josh Kupershmidt <schmiddy@gmail.com>
CC: Tom Lane <tgl@sss.pgh.pa.us>, Chris <lists@deksai.com>,
	pgsql-performance@postgresql.org
Subject: Re: stats collector suddenly causing lots of IO
References: <20100413170105.GA29571@chris-laptop.a2hosting.com>
	<25952.1271370711@sss.pgh.pa.us>
	<z2s4ec1cf761004160739w3ac5511jd39263dd043e2da6@mail.gmail.com>
	<9738.1271431432@sss.pgh.pa.us>
	<g2t4ec1cf761004160830q5dff4315rcc0294d342999c35@mail.gmail.com>
	<10082.1271432484@sss.pgh.pa.us>
	<h2p4ec1cf761004160931r47cf4949o9a2fc14529c17ab1@mail.gmail.com>
	<11152.1271436528@sss.pgh.pa.us>
	<m2w4ec1cf761004161043yd59174a5h9fb011a16608d96d@mail.gmail.com>
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Josh Kupershmidt wrote:
> SELECT name, current_setting(name), source FROM pg_settings WHERE
> source != 'default' AND name ILIKE '%vacuum%';
>          name         | current_setting |       source
> ----------------------+-----------------+--------------------
>  vacuum_cost_delay    | 200ms           | configuration file
>  vacuum_cost_limit    | 100             | configuration file
>  vacuum_cost_page_hit | 6               | configuration file
>
>   
> Hopefully changing those three vacuum_cost_* params will speed up the
> manual- and auto-vacuums..

Those only impact manual VACUUM statements.  There's a different set 
with names like autovacuum_vacuum_cost_delay that control the daemon.  
You can set those to "-1" in order to match the regular VACUUM, but 
that's not the default.

You really need to sort out the max_fsm_pages setting too, because until 
that issue goes away these tables are unlikely to ever stop growing.  
And, no, you can't use CLUSTER on the system tables to clean those up.

-- 
Greg Smith  2ndQuadrant US  Baltimore, MD
PostgreSQL Training, Services and Support
greg@2ndQuadrant.com   www.2ndQuadrant.us