Re: random observations while testing with a 1,8B row

Stefan,

On 3/10/06 11:48 AM, "Stefan Kaltenbrunner" <stefan(at)kaltenbrunner(dot)cc> wrote:

> 2 HBAs in the server, 2x2 possible paths to each LUN.
> 6 disks for the WAL and 12 disks for the data

So - you have 18 disks worth of potential bandwidth, not factoring loss due
to RAID. That's roughly 18 * 60 = 1,080 MB/s. If we organized that into
four banks, one for each CPU and made each one RAID5 and left two disks for
spares, you'd have 12 disks working for you at 720MB/s, which is possibly
double the number of active FC channels you have, unless they are all
active, in which case you have a nicely matched 800MB/s of FC.

>> So, from 15 MB/s up to about 20 MB/s.

Gee - seems a long distance from 700 MB/s potential :-)

> the IO-System I use should be capable of doing that if pushed hard
> enough :-)

I would expect some 10x this if configured well.

> interesting to know, but still I'm testing/playing with postgresql here
> not bizgres MPP ...

Sure. Still, what I'd expect is something like 10x this update rate using
the parallelism buried in your hardware.

If you configure the same machine with 4 Bizgres MPP segments running on 4
LUNs I think you'd be shocked at the speedups.

- Luke