Re: Multiplexing Datafiles?

What if I want to multiplex datafiles in my database but not run in ARCHIVELOG mode for some reason, perhaps because the database would generate too much archive or if the database is a warehouse that isn't suited for ARCHIVELOG mode ?

Multiplexing datafiles seem's a good enough request for me, and more to the point , redo logs DO NOT supply all the protection you need, perhaps you meant archived redo ?

"Howard J. Rogers" <howardjr_at_www.com> wrote in message news:3995df0c$1_at_news.iprimus.com.au...
>
> "Rob Jolliffe" <rjolliffe_at_my-deja.com> wrote in message
> news:8n4295$mqp$1_at_nnrp1.deja.com...
> > Hi,
> >
> > I'm just beginning to learn Oracle, and I was reviewing some Email
> > regarding Raid5 vs Raid0 performance. It seems Raid 0 is significantly
> > better for performance - but you lose the redundancy of Raid 5 (or even
> > Raid 1).
> >
> > I was trying to also determine if in a data tablespace it is possible to
> > multiplex (mirror) datafiles the same way you can with a Redo log group.
> > I was totally unable to determine if you are or are not.
> >
>
> Absolutely not. Never has been, and there never will be -because it is
> entirely pointless. The reason for duplexing your data files is,
> presumably, to avoid complete disaster in the event that one of them dies,
> gets deleted, corrupted etc. That is precisely what the Redo Logs are
 there
> for. Provided you've kept all your redo since the time of the last
 backup,
> you can reconstruct any given data file up to the precise time of failure.
>
> So if you're mirroring your Redo, you have provided all the protection
 your
> data files ever need.
>
> (Conceivably, you can use external, hardware mirroring of data files to
> enable recovery to take place *faster* -you just break the mirror and use
> the good copy. No need to wait for all that Redo to be re-played. But
> that's a mean-time-to-recovery issue. It's certainly not necessary).
>
> > Can anyone tell me? I know you can stripe tablespaces - but can you
> > mirror them? Perhaps this requires creating two tablespaces and somehow
> > matching them?
> >
>
> Forget it. There's no such concept in Oracle, because the Redo does all
 the
> protection work we need.
>
> Regards
> HJR
>
>
>
> > Thanks very much
> >
> > -Rob
> >
> >
> > =============
> > From the desk of Rob Jolliffe
> >
> >
> > Sent via Deja.com http://www.deja.com/
> > Before you buy.
>
>
Received on Mon Aug 14 2000 - 07:22:37 CDT