When choosing redundancy for ASM I'd have said that performance was
the last thing that you'd want on the list of considerations. External
redundancy implies that you are doing the data protection outside of
the database - usually on a SAN/NAS with it's own redundant disks. ASM
redundancy implies, at least to me, that your hardware is not in and
of itself redundant - JBOD say - and so you are using ASM instead of a
non-oracle solution. If your test tablespaces are actually on the same
physical hardware then of course the use of normal redundancy implies
more writes to the disks and therefore likely worse performance, on
the other hand if actually you need to do that work skipping it for
the sake of performance is a bit silly really.
On 2/13/07, Syed Jaffar Hussain <sjaffarhussain_at_gmail.com> wrote:
> Hello List,
>
> When we test ASM with normal redudancy vs external redundancy on AIX, we got
> different result of performance.
>
> Queries on tables which reside on the tablespace that is placed with
> external redudancy ASM disk were giving faster result than tables which
> reside with tablespace placed with ASM normal redundancy.
>
> Does any one has similar expreience?
>
> Which redundancy type works for a highly OLTP database?
>
>
>
> --
> Best Regards,
> Syed Jaffar Hussain
> Oracle ACE
> 8i,9i & 10g OCP DBA
>
> http://jaffardba.blogspot.com/
> http://www.oracle.com/technology/community/oracle_ace/ace1.html#hussain
> ----------------------------------------------------------------------------------
> "Winners don't do different things. They do things differently."
--
Niall Litchfield
Oracle DBA
http://www.orawin.info
--
http://www.freelists.org/webpage/oracle-l
Received on Tue Feb 13 2007 - 09:45:23 CST
