Re: DB RAID Setup

On Tue, Nov 18, 2008 at 9:06 AM, Rob Dempsey <Rob.Dempsey_at_5one.co.uk> wrote:

> To use RAID 5 for data, I understand there is a write performance hit but
> this is a data warehouse so should be ok (Ideally I would like that RAID 10
> as well). But to have the index tablespace on RAID 10 and data tablespace on
> RAID 5 I found that strange. When I asked the reason why I was give the
> response 'that is what Oracle recommends'.
>

Reasoning a bit on the matter ( I'm studiously avoiding the use of 'guess') it could be that since this is a DW, a large number of indexes may be repeatedly
dropped and recreated in the course of ETL. As RAID 10 is faster on writes than
RAID 5, this may save some considerable time.

That of course could possibly be mitigated by the proper use of partitioning, and is
also dependent on the design of your DW.

If RAID 10 is good enough for indexes (pseudo-data) it's good enough for real data.
( tongue firmly planted in cheek here :)

Jared Still
Certifiable Oracle DBA and Part Time Perl Evangelist

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