Re: Oracle Performance - RAID vs split tables

Raindrop Support wrote:
>
> Can anyone shed any light on a performance choice?
>
> Many of our customers are worried about disk crashes and the resulting data
> loss so RAID is an obvious solution. We normally recommend hardware RAID5.
>
> However, we have recently been advised by various Oracle gurus that it is
> better for Oracle performance to manually split up the physical locations of
> individual tables, indices and logs across physical disks. This cannot be
> done with RAID. Additionally, we have been advised that RAID5 actually
> *slows down* Oracle.
>
> Any comments?
>
> Replies to newsgroup please.

RAID5 is really only good if you are doing heavy reads with hardly any writes. An oracle database is constantly updating it's files. Even if you aren't doing any writes to any tables, the RDBMS is updating it's data dictionary and virtual performance tables. For that reason, RAID5 is not recommended. If you are worried about data redundancy and still want to keep up performance, try RAID1 (or RAID0+1) or mirroring. You'll get high data transfer rates while have redundancy. The only major drawback is the extra disk space you need to mirror.

HTH,
Brian Received on Thu Sep 09 1999 - 09:33:27 CDT