On Fri, Feb 20, 2009 at 2:34 PM, Battle Mage <battlemage@xxxxxxxxx> wrote: > I have a server box that has 4GB of RAM, Quad core CPU AMD Opteron 200.152 > Mhz (1024 KB cache size each) with plenty of hard drive space. > > I installed both postgresql 8.2.6 and 8.3.3 on it. I've created a basic > test db and used > pgbench -i -s 1 -U test -h localhost test > to create a sample test db. > > Then, to benchmark the postgreSQLs, I executed this separately on each of > them: > pg_bench -h localhost -d test -t 2000 -c 50 -s 50 -U test > (2000 transactions per client, 50 clients, scalability factor of 50) If you're goint to test with -c50 you should initialize with -s50. -s 50 after initialization doesn't mean anything. It's the first pgbench -i -s nnn where you need to set nnn to 50 (or higher) if you're gonna test with it. > Using the above, > I get on postgreSQL 8.2.6: > Load average: Between 3.4 and 4.3 > tps = 589 (including connections establishing) > tps = 590 (excluding connections establishing) > > I get on postgreSQL 8.3.3 > Load: Between 4.5 and 5.6 > tps = 949 (including connections establishing) > tps = 951 (excluding connections establishing) Nice improvement. > The amount of tps almost doubled, which is good, but i'm worried about the > load. For my application, a load increase is bad and I'd like to keep it > just like in 8.2.6 (a load average between 3.4 and 4.3). What parameters > should I work with to decrease the resulting load average at the expense of > tps? I agree with the other poster. Why is a load increase bad? What does it mean here. I've got one load that runs smoothly with a load factor of 60 to 150 on a server, while the same server with a different load starts to bog down with load factors between 10 and 15. It's a very broad measurement. Don't try to tune to your load factor, try to tune to the real load being applied, and opimtize there. > Down below is my 8.3.3 configuration file. I removed everything that is > commented since if it's commented, it's default value. I also removed from > the sample below parameters related to logging. > > ===== postgresql.conf begins ===== > fsync = off # turns forced synchronization on or off So, I assume either your data is easily reproduceable, unimportant, or replicated in such a way that you can survive sudden power loss / kernel crash? Also, is there are reason you're running two different out of date releases of postgresql? -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
