On Thu, 2010-12-23 at 11:24 -0700, Scott Marlowe wrote: > On Thu, Dec 23, 2010 at 10:37 AM, Przemek Wozniak <wozniak@xxxxxxxx> wrote: > > When testing the IO performance of ioSAN storage device from FusionIO > > (650GB MLC version) one of the things I tried is a set of IO intensive > > operations in Postgres: bulk data loads, updates, and queries calling > > for random IO. So far I cannot make Postgres take advantage of this > > So, were you running a lot of these at once? Or just single threaded? > I get very good io concurrency with lots of parallel postgresql > connections on a 34 disk SAS setup with a battery backed controller. In one test I was running between 1 and 32 clients simultaneously writing lots of data using copy binary. The problem is that with a large RAM buffer it all goes there, and then the background writer, a single postgres process, will issue write requests one at a time I suspect. So the actual IO is effectively serialized by the backend. -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
