On Fri, Aug 28, 2009 at 2:08 AM, Greg Smith<gsm...@gregsmith.com> wrote: > > This sort of workload involves random I/O rather than sequential. On > regular hard drives this normally happens at a tiny fraction of the speed > because of how the disk has to seek around. Typically a single drive > capable of 50-100MB/s on sequential I/O will only do 1-2MB/s on a completely > random workload. You look like you're getting somewhere in the middle > there, on the low side which doesn't surprise me. > > The main two things you can do to improve this on the database side: > > -Increase checkpoint_segments, which reduces how often updated data has to > be flushed to disk > > -Increase shared_buffers in order to hold more of the working set of data in > RAM, so that more reads are satisfied by the database cache and less data > gets evicted to disk.
After that you have to start looking at hardware. Soimething as simple as a different drive for indexes and another for WAL, and another for the base tables can make a big difference. -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
