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From: Josh Berkus <josh@agliodbs.com>
Organization: Aglio Database Solutions
To: Nick Barr <nicky@chuckie.co.uk>
Subject: Re: go for a script! / ex:  PostgreSQL vs. MySQL
Date: Fri, 10 Oct 2003 13:38:18 -0700
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Cc: pgsql-performance@postgresql.org
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	<200310101034.52073.josh@agliodbs.com>
	<3F86F5BB.90605@chuckie.co.uk>
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Nick,

> Sounds good to me. I will carry on working on it but I would definitely
> need some help, or at least a list of parameters to tweak, and some
> recomended values based on data about the puter in question.

> shared_buffers = 1/16th of total memory
> effective_cache_size = 80% of the supposed kernel cache.

But only if it's a dedicated DB machine.   If it's not, all memory values 
should be cut in half.

> I guess we also may be able to offer a simple and advanced mode. Simple
> mode would work on these recomended values, but kick it into advanced
> mode and the user can tweak things more finely. This would only be
> recomended for the Guru's out there of course. This may take a bit more
> time to do though.

What I would prefer would be an interactive script which would, by asking the 
user simple questions and system scanning, collect all the information 
necessary to set:

max_connections
shared_buffers
sort_mem
vacuum_mem
effective_cache_size
random_page_cost
max_fsm_pages
checkpoint_segments & checkpoint_timeout
tcp_ip

and on the OS, it should set:
shmmax & shmmall
and should offer to create a chron job which does appropriate frequency VACUUM 
ANALYZE.

> As I said in the previous email I have only got access to Linux, so
> cross-platform help would be good too. I will try to make it as easy to
> do cross platform stuff as possible of course.

Let's get it working on Linux; then we can rely on the community to port it to 
other platforms.  I myself can work on the ports to Solaris and OS X.

-- 
Josh Berkus
Aglio Database Solutions
San Francisco