Re: redo log duplexing question

From: Sybrand Bakker <postbus_at_sybrandb.demon.nl>
Date: Wed, 20 Oct 1999 18:14:46 GMT
Message-ID: <380e0680.22405810@news.demon.nl>

On 20 Oct 1999 13:51:21 -0400, buzzwang_at_churchill.ourvillage.com (David F. Newman) wrote:

>Hi,
> I was once told in the backup and recovery
>class that it is a good idea to
>
>1) Mirror the disk that redo logs sit on and
>2) Duplex the redo logs themselves.
>
>So, essentially, each redo group exists on
>four disks. I've been doing that but it has
>come up that it might be a performance issue
>writting to four locations for each redo group.
>I honestly can't remember the reason for doing
>both. Does one need to only do one or the
>other? Thanks for any input.
>
>--
>David F. Newman
>Oracle DBA/Unix admin
>dnewman_at_ourvillage.com

I would prefer option 2)
Oracle doesn't 'see' any hardware level mirroring, so if you loose that redo log file, it doesn't know about the existence of the mirror.

Hth,

Sybrand Bakker, Oracle DBA Received on Wed Oct 20 1999 - 13:14:46 CDT