Re: Optimization postgresql 8.1.4 FC 6 X64 ?

I also think there have been changes in pgbench itself.

Make sure you run the same pgbench on both servers.

Dave
On 24-Mar-07, at 6:44 AM, Heikki Linnakangas wrote:

> 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
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