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 RAI=
D5.
> =

> However, we have recently been advised by various Oracle gurus that it =
is
> better for Oracle performance to manually split up the physical locatio=
ns 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.

Hi,

usually I recommend Raid 0/1 with mirrors. I have multiple really great database running
on SUN E 10.000 under Solaris 2.6 . If you take a lot of disks ( for example 20 disks )
you can define very small stripes 0/1 across (!!) all disks which can form raw devices or =

filesystem - just as you want . Putting datafiles on these devices will always result in that a tablespace is across all disks. For IO you will see that all disks will react.
I would only use RAID5 if nothing else is available ( for example A3500 storage from SUN ).
Splitting table manually across disks is very handsome because you wonŽ= t
be able to have a single disk for a single table. Putting more than one table into a tablespace could
result in concurrent IO on the same disk. =

Hope youŽll find the right way.

Greetings Hans Pfeiffer Received on Mon Sep 13 1999 - 16:06:57 CDT