From: Shaun Thomas <sthomas@peak6.com>
To: Jesper Krogh <jesper@krogh.cc>
Cc: pgsql-performance@postgresql.org
Subject: Re: Summaries on SSD usage?
Date: Fri, 2 Sep 2011 09:30:07 -0500
Message-ID: <4E60E86F.2070901@peak6.com> (raw)
In-Reply-To: <4E60583A.4040302@krogh.cc>
References: <CAFcOn28h1-uD9Q11rKve2W3BxuUajHX96mXvMcQ=tQsn3pvKgg@mail.gmail.com>
<F9B45497-E978-467E-9D00-16A32FA7B6D8@nasby.net>
<4E60583A.4040302@krogh.cc>
On 09/01/2011 11:14 PM, Jesper Krogh wrote:
> It is "really expensive" to go over 512GB memory and the performance
> regression for just hitting disk in a system where you assume
> everything is in memory is really huge. SSD makes the "edge" be a bit
> smoother than rotating drives do.
Ironically, this is actually the topic of my presentation at Postgres
Open. We transitioned to NVRAM PCI cards for exactly this reason. Having
a giant database in cache is great, until a few reads come from your
slow backing disks, or heaven-forbid, you have to restart your database
during a high transactional period.
Lemme tell ya... no RAID-10 in the world can supply 12k TPS with little
to no warning. A good set of SSDs or PCI cards can.
--
Shaun Thomas
OptionsHouse | 141 W. Jackson Blvd. | Suite 800 | Chicago IL, 60604
312-676-8870
sthomas@peak6.com
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To: pgsql-performance@postgresql.org
Cc: sthomas@peak6.com, jesper@krogh.cc
Subject: Re: Summaries on SSD usage?
In-Reply-To: <4E60E86F.2070901@peak6.com>
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