Re: Why control files are needed for restore of hot backup?

On 21 May 2002 17:48:29 -0700, danielroy10_at_hotmail.com (Daniel Roy) wrote:

>Hi everyone,
> I have a question which will probably look obvious to many, but I'm
>just starting with Oracle! If I take a hot backup of a database, using
>for each tablespace:
>- alter tablespace bla-bla begin backup
>- I copy the tablespace datafiles to the backup directory
>- alter tablespace bla-bla end backup
>
>I also include in my backup the archive logs generated during the
>backup.
>Now my question is if the datafile structure of the database doesn't
>change, do I really need the control file to also be backed up? It
>seems to me that at recovery time, re-creating the control files
>should be the same result than using a control file from during the
>backup. My feeling is that in both cases, Oracle relies exclusively on
>the SCN's of the datafile headers in order to decide which datafile
>needs recovery, and which one doesn't.
>
>Daniel

Study the difference between *complete* recovery (all files present) and *incomplete* recovery (backup controlfile) and don't try to be 'smart'. During *complete* recovery Oracle compares the SCNs in the controlfile and the datafiles.

Regards

Sybrand Bakker, Senior Oracle DBA

To reply remove -verwijderdit from my e-mail address Received on Wed May 22 2002 - 00:16:02 CDT