Re: Optimization postgresql 8.1.4 FC 6 X64 ?

amrit angsusingh wrote:
> I try to change my database server from the older one ie. 2Cpu Xeon 2.4 32
> bit 4Gb SDram Hdd SCSI RAID 5 and FC 3 ix86 with 7..4.7 PG to the newer one
> with 2CPU Xeon 3.0 64 Bit 4Gb DDRram SCSI Raid5 and FC6 X64 PG 8.14 and try
> to use rather the same parameter from the previous postgresql.conf :-
> ...
> I use pgbench to test the speed of my older database server and the result
> is
>
> bash-3.00$ pgbench test -t 20 -c 30 -s 50
> ...

-t 20 is not enough to give repeatable results. Try something like -t 1000.

The speed of pgbench in that configuration (scaling factor 50, fsync
enabled) is limited by the speed you can fsync the WAL. There isn't much
you can do in postgresql.conf for that. If you get similar results with
higher -t setting, it may be because your new RAID and drives have
slightly higher latency.

You're better off testing with real queries with your real database.

--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com