On Sun, 25 Jan 2009, M. Edward (Ed) Borasky wrote:
Actually, this isn't so much a 'pgbench' exercise as it is a source of 'real-world application' data for my Linux I/O performance visualization tools. I've done 'iozone' tests, though not recently. But what I'm building is an I/O analysis toolset, not a database application.
Are these performance results when the analysis tools are active or inactive? Have you investigated whether the analysis tools might be slowing the I/O down at all?
...they told me that it was because the drive was re-ordering operations according to its own internal scheduler!
A modern SATA drive with native queuing will do that. SCSI drives have been doing that for twenty years or so.
Matthew -- I pause for breath to allow you to get over your shock that I really did cover all that in only five minutes... -- Computer Science Lecturer -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
