On 1/11/05 2:50 pm, "Jon Brisbin" <jon.brisbin@xxxxxxxxxxxxxxxxxxxx> wrote: > On Mon, 31 Oct 2005 17:16:46 -0600 > "PostgreSQL" <martin@xxxxxxxxxxx> wrote: > >> We're running 8.1beta3 on one server and are having ridiculous >> performance issues. This is a 2 cpu Opteron box and both processors >> are staying at 98 or 99% utilization processing not-that-complex >> queries. Prior to the upgrade, our I/O wait time was about 60% and >> cpu utilization rarely got very high, now I/O wait time is at or near >> zero. >> >> I'm planning to go back to 8.0 tonight or tomorrow night but thought >> I'd check the pqsql-performance prophets before I gave it up. > > I have a stock FreeBSD 5.4 box that I put 8.1 on last night. I ran > pgbench against it and my tps dropped from ~300tps in 8.0.3 to 20tps > in 8.1. That's right. 20. No changes in any system configuration. No > data in the new 8.1 database, only the pgbench init'ed stuff. 25 > clients, 100 and 1000 transactions with a scaling factor of 10, which > gives me 1,000,000 tuples to shoot through. > > I wiped out the 8.1 installation, put 8.0.4 in it's place, and > pgbenched it again. ~300tps again. > > It's not a problem with system configuration if 8.0 works fine, but 8.1 > has problems, unless there is something that 8.1 needs tweaked that 8.0 > doesn't. In that case, I just need to know what that is and I can tweak > it. Hi Jon, Did you run the bundled version of pgbench against it's own installation? There we some changes to pgbench for 8.1, and I have to wonder (bearing in mind I haven't really looked at them) whether they could be affecting things in any way. Do you get comparable results running the 8.0 pgbench against both server versions? Regards, Dave
