Re: Controlfile to destination

From: koert54 <koert54_at_nospam.com>
Date: Tue, 27 Nov 2001 21:04:42 GMT
Message-ID: <KdTM7.8677$825.2700983358@hestia.telenet-ops.be>

Ok ...
How do you make a consistent backup of your datafiles ? You don't - it's a fuzzy backup and you recover it by using the archives ... But you have 'begin backup' / 'end backup' to freeze the header (SCN) of the DB files...

How do you make a consistent backup of your redologfiles ? You can't ! They constantly change due to commits, checkpointing etc You do not have a begin/end backup command - backing up redologs is pointless...
Heck even when performing cold backups and you did a normal shutdown (not a shutdown abort) you don't
even need the redologs on your backup. (because their not needed for instance recovery)

How do you make a consistent backup of your controlfile ? Because, just like redologs, the controlfile changes all the time you can't guarantee a consistent backup ... unless you dump it to ASCII (alter backup controlfile to trace) or recreate a binary copy (alter backup controlfile to 'destination'). Now I guess you want to do the following :

1. shutdown the DB
2. replace the current controlfiles with the dump you just took
3. start up the DB

THIS WON'T WORK because the SCN of the controlfile is out of sync with the rest of the DB

The binary dump can only be used when recovering the DB with the 'using backup controlfile' clause of the recover command -> recover database using backup controlfile ;

hope this helped ...
koert

"Gopal" <oracleinform_at_yahoo.com> wrote in message news:1ed02c3a.0111262132.4095b0db_at_posting.google.com...
> Hi All,
>
> I would like to know why we have to do alter database backup
> controlfile to 'destination' what is the usefulness especially in hot
> backup , it says it can start the database with this file but I
> cannot . it gives me the error database not properly created.How to
> use this file if the controlfiles are lost and cannot give alter
> database backup controlfile to trace. Please help. Thanks in advance.
>
> With kind regards
Received on Tue Nov 27 2001 - 15:04:42 CST