On 18-Nov-05, at 1:07 AM, Luke Lonergan wrote:
Greg,
On 11/17/05 9:17 PM, "Greg Stark" <gsstark@xxxxxxx> wrote:
Ok, a more productive point: it's not really the size of the
database that
controls whether you're I/O bound or CPU bound. It's the available
I/O
bandwidth versus your CPU speed.
Postgres + Any x86 CPU from 2.4GHz up to Opteron 280 is CPU bound
after
110MB/s of I/O. This is true of Postgres 7.4, 8.0 and 8.1.
A $1,000 system with one CPU and two SATA disks in a software RAID0
will
perform exactly the same as a $80,000 system with 8 dual core CPUs
and the
world's best SCSI RAID hardware on a large database for decision
support
(what the poster asked about).
Now there's an interesting line drawn in the sand. I presume you have
numbers to back this up ?
This should draw some interesting posts.
Dave
Regards,
- Luke
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