From: Mark Kirkwood <markir@paradise.net.nz>
To: David Lang <dlang@invendra.net>
Cc: Mitch Skinner <lists@arctur.us>
Cc: Kevin Brown <blargity@gmail.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Simple Join
Date: Sat, 17 Dec 2005 10:11:19 +1300
Message-ID: <43A32D77.4020500@paradise.net.nz> (raw)
In-Reply-To: <Pine.LNX.4.62.0512152003460.2807@qnivq.ynat.uz>
References: <200512141603.52583.blargity@gmail.com>
<7484.1134600423@sss.pgh.pa.us>
<1134629567.14248.27.camel@firebolt>
<200512150148.16125.blargity@gmail.com>
<1134644526.14248.60.camel@firebolt>
<43A1C40D.8040006@paradise.net.nz>
<Pine.LNX.4.62.0512152003460.2807@qnivq.ynat.uz>
David Lang wrote:
> On Fri, 16 Dec 2005, Mark Kirkwood wrote:
>
>>
>> Right on. Some of these "coerced" plans may perform much better. If
>> so, we can look at tweaking your runtime config: e.g.
>>
>> effective_cache_size
>> random_page_cost
>> default_statistics_target
>>
>> to see if said plans can be chosen "naturally".
>
>
> Mark, I've seen these config options listed as tweaking targets fairly
> frequently, has anyone put any thought or effort into creating a test
> program that could analyse the actual system and set the defaults based
> on the measured performance?
>
I am sure this has been discussed before, I found this thread -
http://archives.postgresql.org/pgsql-performance/2004-07/msg00189.php
but I seem to recall others (but offhand can't find any of them).
I think that the real difficultly here is that the construction of the
test program is non trivial - for instance, the best test program for
tuning *my* workload is my application with its collection of data, but
it is probably not a good test program for *anyone else's* workload.
cheers
Mark
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To: pgsql-performance@postgresql.org
Cc: markir@paradise.net.nz, dlang@invendra.net, lists@arctur.us, blargity@gmail.com
Subject: Re: Simple Join
In-Reply-To: <43A32D77.4020500@paradise.net.nz>
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