Re: tablespaces and DB administration

pgsql(at)mohawksoft(dot)com wrote:

>
>As for IDE RAID, IDE RAID is an awesome idea. SCSI disks are just too
>expensive. Infortrend has a cool IDE to SCSI or Fibre RAID system that
>rocks.
>
>

Obviously, you're caught by those marketing geeks. You're taking
bandwidth (MB/s)as performance index, which is irrelevant for database
access. Limiting factor is average access time, and there's still no 3ms
seek time ide disk. This is not a problem of the interface, it's just a
fact that (for marketing reasons?) all server grade disks are not
equipped with ide.
A good raid system will be able to have independend seeks issued on all
disks in parallel, thus scaling by spindle number (only for parallel
accessing processes of course, not for serialized access). What you're
proposing is that the app should parallelize it, instead of leaving this
to the instance that can (should) do this better.

Regards,
Andreas