From: Mark Mielke <mark@mark.mielke.cc>
To: Luke Lonergan <llonergan@greenplum.com>
Cc: Carlo Stonebanks <stonec.register@sympatico.ca>
Cc: pgsql-performance@postgresql.org
Subject: Re: random_page_costs - are defaults of 4.0 realistic for SCSI RAID 1
Date: Mon, 10 Sep 2007 16:52:56 -0400
Message-ID: <46E5AEA8.4010809@mark.mielke.cc> (raw)
In-Reply-To: <C30AF4C7.4230B%llonergan@greenplum.com>
References: <C30AF4C7.4230B%llonergan@greenplum.com>
Luke Lonergan wrote:
> Should be a lot higher, something like 10-15 is approximating accurate.
>
In my own case, I have a much smaller database that I normally work
with, where everything should fit in memory (100 Mbytes?), and reducing
it to 3.0 has resulted in consistently better timings for me. I think
this means that the planner doesn't understand my database size :
effective memory size ratio. :-)
Anyways - my point is that if you change the default to 10 you may hurt
people like me.
Cheers,
mark
--
Mark Mielke <mark@mielke.cc>
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To: pgsql-performance@postgresql.org
Cc: mark@mark.mielke.cc, llonergan@greenplum.com, stonec.register@sympatico.ca
Subject: Re: random_page_costs - are defaults of 4.0 realistic for SCSI RAID 1
In-Reply-To: <46E5AEA8.4010809@mark.mielke.cc>
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