Re: How to improve db performance with $7K?

Alex Turner wrote:
> Does it really matter at which end of the cable the queueing is done
> (Assuming both ends know as much about drive geometry etc..)?

Good question.  If the SCSI system was moving the head from track 1 to
10, and a request then came in for track 5, could the system make the
head stop at track 5 on its way to track 10?  That is something that
only the controller could do.  However, I have no idea if SCSI does
that.

The only part I am pretty sure about is that real-world experience shows
SCSI is better for a mixed I/O environment.  Not sure why, exactly, but
the command queueing obviously helps, and I am not sure what else does.


--
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 359-1001
  +  If your life is a hard drive,     |  13 Roberts Road
  +  Christ can be your backup.        |  Newtown Square, Pennsylvania 19073