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From: Steve Atkins <steve@blighty.com>
To: PostgreSQL Developers <pgsql-hackers@postgresql.org>
In-Reply-To: <7473.1212625397@sss.pgh.pa.us>
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Subject: Re: Overhauling GUCS 
Date: Wed, 4 Jun 2008 18:20:49 -0700
References: <48409D1E.3070208@agliodbs.com>
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	<Pine.GSO.4.64.0806020452220.26912@westnet.com>
	<17932.1212415926@sss.pgh.pa.us>
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	<4846A483.8000001@pse-consulting.de>
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	<29525.1212613052@sss.pgh.pa.us>
	<48472E47.7030701@dunslane.net> <7473.1212625397@sss.pgh.pa.us>


On Jun 4, 2008, at 5:23 PM, Tom Lane wrote:

> Andrew Dunstan <andrew@dunslane.net> writes:
>> Tom Lane wrote:
>>> * Can we build a "configuration wizard" to tell newbies what  
>>> settings
>>> they need to tweak?
>
>> That would trump all the other suggestions conclusively. Anyone  
>> good at
>> expert systems?
>
> How far could we get with the answers to just three questions:
>
> * How many concurrent queries do you expect to have?
>
> * How much RAM space are you willing to let Postgres use?
>
> * How much "overhead" disk space are you willing to let Postgres use?
>
> concurrent queries drives max_connections, obviously, and RAM space
> would drive shared_buffers and effective_cache_size, and both of them
> would be needed to size work_mem.  The third one is a bit weird but
> I don't see any other good way to set the checkpoint parameters.
>
> If those aren't enough questions, what else must we ask?  Or maybe  
> they
> aren't the right questions at all --- maybe we should ask "is this a
> dedicated machine or not" and try to extrapolate everything else from
> what we (hopefully) can find out about the hardware.

I'd be interested in putting together a framework+GUI client to do this
cleanly in a cross-platform (Windows, Linux, Solaris, OS X as a bare
minimum) sort of way, if no-one else already has such a thing.

A framework doesn't get you all the way there, but it makes it a
whole lot easier to work on what base data and information you
need, and how easy it is to map pgsql-performance and #postgresql
gut feel onto something more algorithmic.

Cheers,
   Steve