On 05/22/2013 08:30 AM, Merlin Moncure wrote:
I'm not claiming to work with extremely high transaction rate systems but then again neither are most of the people reading this list. Disk drives are obsolete for database installations.
Well, you may not be able to make that claim, but I can. While we don't use Intel SSDs, our first-gen FusinoIO cards can deliver about 20k PostgreSQL TPS of our real-world data right off the device before caching effects start boosting the numbers. These days, devices like this make our current batch look like rusty old hulks in comparison, so the gap is just widening. Hard drives stand no chance at all.
An 8-drive 15k RPM RAID-10 gave us about 1800 TPS back when we switched to FusionIO about two years ago. So, while Intel drives themselves may not be able to hit sustained 100x speeds over spindles, it's pretty clear that that's a firmware or implementation limitation.
The main "issue" is that the sustained sequence scan speeds are generally less than an order of magnitude faster than drives. So as soon as you hit something that isn't limited by random IOPS, spindles get a chance to catch up. But those situations are few and far between in a heavy transactional setting. Having used NVRAM/SSDs, I could never go back so long as the budget allows us to procure them.
A data warehouse? Maybe spindles still have a place there. Heavy transactional system? Not a chance.
-- Shaun Thomas OptionsHouse | 141 W. Jackson Blvd. | Suite 500 | Chicago IL, 60604 312-676-8870 sthomas@xxxxxxxxxxxxxxxx ______________________________________________ See http://www.peak6.com/email_disclaimer/ for terms and conditions related to this email -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
