Re: Performance question: single datafile vs multiple datafiles

On Fri, 01 Mar 2002 18:28:10 GMT, Ricky Sanchez <rsanchez_at_more.net> wrote:

>Sybrand-
>
>How does file size relate to dbwr average scan depth?
>
>Also, in a non-raid environment, don't multiple data files afford the
>opportunity to spread IO among many disks and reduce latency?
>
>- ricky
>

<quote>
there is no reason to have multiple
 datafiles for a single tablespace on the *same physical disk*. </quote, asterixes added>

Also I didn't discuss file size, I discussed the *number* of files. I consistently get complaints from Toad on dbwr_average_scan_depth, telling me the number of files is too high, even if there is not much difference between db_files and the actual number of files. This might be a V7 thingy, but Toad is complaining about it. Usually the complaint arises for databases with say 7-10 tablespaces each consisting of 5 or more files, all files of a single tablespace being located on the same disk. Does this reduce latency? I don't think so. I also think in your scenario you should software stripe your tables. If you don't do that, it is unlikely to help you.

So now please tell me I'm an idiot. You have done that before to me, so I'm prepared for it.

Regards

Sybrand Bakker, Senior Oracle DBA

To reply remove -verwijderdit from my e-mail address Received on Fri Mar 01 2002 - 16:49:27 CST