Re: Physical Layout of disk to use Oracle

Thanks Adon.

You said: "Underutilized disk SYSTEM, ARCHIVE and INDEX tablespaces, probable hotspot on ROLLBACK, possibly over utilized DATA."

could you please elaborate on this....? I am thinking of implementing  RAID 5 for my DB which would have 6 disk - each 36GB.do I still need to consider SAME....? Kindly elaborate. I read SAME Paper @ OTN Web site but it seems it does what RAID 5 does....THANKS!

Also, MK in his/her reply mentioned that to have DATA and INDEX on same TABLESPACE......I don't think so he/she is right on this....correct me on this if I am wrong.

MILLION Thanks!

adon_at_cool.iskon.local (Adon Keber) wrote in message news:<slrnbmdodc.1pc.adon_at_cool.iskon.local>...
> On Tue, 16 Sep 2003 06:12:17 +1000, Howard J. Rogers wrote:
> >>
> >> hdisk2 --> Oracle Appplication Software
> >> hdisk3 --> SYSTEM Tablespaces(for all instances) + Control File 1
> >> hdisk4 --> ROLLBACK Tablespace + Redo Log files + Control File 2
> >> hdisk5 --> DATA Tablespace + Control File 3
> >> hdisk6 --> INDEX Tablespace + TEMP Tablespace
> >> hdisk7 --> ARCHIVE Redo Log destination disk.
> >>
> >> Can anyone point out if there would be any issues in the above Layout.
> >> Please feel free to be as critical as possible....after all I learn
> >> from my mistakes only.
> >>
> >>
> >> THANKS!
> >
> >No real advice this time... except that you're going to get a lot of people
> >telling you to "Stripe and Mirror Everything" (SAME), and before you take
> >that advice (which is certainly an easy approach), you might care to check
> >out www.ixora.com.au, and see what Steve Adams has to say on the subject.
>
> This is the probably the only thing where I don't agree with Steve Adams.
>
> SAME does NOT show lack of DBA skill but it is compromise between conflicting
> requirements. For example in above layout I see underutilized disks (with
> assumption that all the hdisk* is the same) with SYSTEM, ARCHIVE and
> INDEX tablespaces, probable hotspot on ROLLBACK, possibly over utilized DATA.
>
> Designing optimal layout is hard and requires knowledge of
> applications. The knowledge the DBA mostly don't have in time
> of instance creation. Also applications are changed or new applications are
> added to the same instance and load patterns are constantly changed
> throughout life of the instance.
> Also many db instances are both OLTP and DWH in nature so
> creating optimal physical layout is almost impossible.
> Should I redesign DB physical layout every time some programmer predicts that
> his new application would have tables of 500Mb-1Gb in month or two. Or
> should I add few new disks just for him?
>
> Also Adams himself says: "Indiscriminate broad striping randomizes
> all I/O and makes service times uniform." And I say - makes service times
> more uniform and more predictable over the time.
>
> a.
Received on Tue Sep 16 2003 - 14:36:58 CDT