Re: Multiple Datafiles and performance?

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).

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

Tanel.

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Author: Tanel Poder
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