I finished the little benchmarking on our server and the results are quite curios. With the numbers from http://sitening.com/tools/postgresql-benchmark/ in mind i did ./pgbench -i pgbench and then performed some pgbench tests, for example ./pgbench -c 1 -t 1000 -s 1 pgbench starting vacuum...end. transaction type: TPC-B (sort of) scaling factor: 1 number of clients: 1 number of transactions per client: 1000 number of transactions actually processed: 1000/1000 tps = 50.703609 (including connections establishing) tps = 50.709265 (excluding connections establishing) So our server with two 3.00 GHz Xeon CPUs and 2GB has about 5% of the performance of the server described in the article! I did some tests on a Xen machine running on my workstation and the results are about 400-500tps which seems to be quite reasonable. I also tried to disable drbd and put the data directory elsewhere, but the performance was the same. any ideas? thx, Peter 2006/10/5, Alexander Staubo <alex@xxxxxxxxxxxxxxx>:
It appears to me that work_mem is a more significant configuration option than previously assumed by many PostgreSQL users, myself included. As with many database optimizations, it's an obscure problem to diagnose because you generally only observe it through I/O activity. One possibility would be to log a warning whenever work_mem is exceeded (or exceeded by a certain ratio). I would also love a couple of new statistics counters tracking the amount of work memory used and the amount of work memory that has spilled over into pgsql_tmp. Alexander. On Oct 5, 2006, at 10:48 , Peter Bauer wrote: > Hi all, > > inspired by the last posting "Weird disk write load caused by > PostgreSQL?" i increased the work_mem from 1 to 7MB and did some > loadtest with vacuum every 10 minutes. The system load (harddisk) went > down and everything was very stable at 80% idle for nearly 24 hours! > I am currently performing some pgbench runs to evaluate the hardware > and configuration for the system but i think the biggest problems are > solved so far. > > thx everybody, > Peter > > 2006/10/2, Tom Lane <tgl@xxxxxxxxxxxxx>: >> Ray Stell <stellr@xxxxxxxxxx> writes: >> > How would one determine the lock situation definitively? Is there >> > an internal mechanism that can be queried? >> >> pg_locks view. >> >> regards, tom lane >> >> ---------------------------(end of >> broadcast)--------------------------- >> TIP 2: Don't 'kill -9' the postmaster >> > > ---------------------------(end of > broadcast)--------------------------- > TIP 4: Have you searched our list archives? > > http://archives.postgresql.org
