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
______________________________________________
See http://www.peak6.com/email_disclaimer.php
for terms and conditions related to this email
