Re: 2 Quick Question: Datafiles/Performance and Deleting a Database

To answer your second question, 5 1Gb files would normally yield a faster-operating database than 1 5Gb file (or, 4 500Mb are better than 1 2Gb, as a more universal Unix example). For systems configured to use synchronous I/O, O/S write operations need to acquire a file lock to update the file. This is usually a faster operation with smaller files. In addition, I've always had better luck with maintenance. although I'm not positively sure why (I'd guess it's along the same line of thinking). Restoring 4 500Mb files has always taken less elapsed time than restoring 1 2Gb file, for example.

Suresh Bhat wrote:

> Hi,
>
> Chuck <chuck_at_phi.org> wrote in article
> <382f11f1.2250926_at_client.nw.news.psi.net>...
> >
> > 1)
> >
> > This may be a dumb question, but what is the proper procedure to
> > delete a database? (I have three databases all using their own
> > instance nad need to delete one of them)
>
> Make sure you have correct ORACLE_SID and ORACLE_HOME set.
>
> svrmgrl
> connect internal
> shutdown
> exit
>
> On UNIX prompt:
>
> ps -ef |grep $ORACLE_SID
>
> If the processes are still running for the database that you are trying to
> delete, then you did not shutdown
> the intended database. Try shutdwon immediate or abort.
>
> You can also kill all the processes via UNIX prompt. Not a good idea. Do
> it only when there is no way to
> shutdown the database even with abort option. Then you will have to remove
> $ORACLE_HOME/dbs/sgadef$ORACLE_SID.dbf file.
>
> Delete all datafiles, log files and control files. If you have named them
> *.dbf, *.log and *.ctl, then it is
> easy to simply say in each of the directories where these files are stored.
>
> rm *.dbf *.log *.ctl
>
> I hope you have the directories such /u01/$ORACLE_SID/tools.dbf etc. for
> each of your 3 databases.
>
> I believe that is it.
>
> > 2)
> > Will their be a significant performance difference between the
> > following two configurations?
> >
> > Config. 1
> >
> > 5 1gig datafiles on the same physcail disk (not contiguous on the
> > disk)
> This would be my choice.
>
> >
> > Config 2
> >
> > 1 5gig datafile on the same physical disk
>
> You cannot have more than 2g datafiles on most UNIX platforms.
> >
>
> Suresh Bhat
> Oracleguru
> www.oracleguru.net
>
> >
> > Thanks,
> > Chuck
> >

--

John Clarke                             (888) 363.2955
Managing Principal Consultant           (248) 593.9935
Centroid Systems, Inc.                  jclarke_at_centroidsys.com
===============================================================