Patrick TJ McPhee wrote:
I have a Red Hat ELsmp system running on a dual opteron hp server with 16 gigs of memory. I believe the RH installation is straight out of the box. I've compiled postgres 8.1.4 from sources. The problem is that query performance is horrible, and I can't think why, although it seems clear the problem is outside the query engine. For instance, "select 1" takes on the order of 100ms. Explain analyze doesn't shed much light on why this might be:
I've had this problem on a old version of redhat. It turned out that the driver included with redhat for the raid-controller was very slow - i think that it was fsync-performance which was really bad with that driver. The controller was as adaptec aacraid - in the end, we used debian, and a recent 2.6 kernel, and things were much faster. greetings, Florian Pflug
