Re: Multiple Datafiles and performance?

At 09:59 AM 8/7/2003 -0800, you wrote:
>Hi!
>
> > The benefits of spreading the data over as many physical access paths ( ~
> > disks ) using multiple datafiles notwithstanding, there is always the case
> > of too much. Keep in mind that at checkpoint time the DBWR need to visit
> > the header of every ( non read-only ) datafile. That's unlikely to be an
>
>The number of files had some impact in older Oracle versions (7.x).
>
>Starting from 8.0 I believe, this issue is somewhat relieved, as you
>probably know. Not all file headers are updated together and the update
>doesn't have to go to disk immediately (this goes for checkpoints caused by
>log switches).

Actually I didn't or else I wouldn't have made the point. I guess that is how myths start and get perpetuated: by no keeping up with changes.

>Also, in older versions db_files parameter affected DBWR batch size and some
>buffer cache structures as well, IIRC.
>
>The biggest number of files I've had in a production database is about 1150,
>960MB each. On WindowsNT4... =8Žo

Wolfgang Breitling
Oracle7, 8, 8i, 9i OCP DBA
Centrex Consulting Corporation
http://www.centrexcc.com

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