Re: recovery without control file and online redo log

Well, the question is no clearer, and the response can't get any clearer either.

Without redo log backups, you must open the database with a resetlogs, which will re-create them.

Without a control file, you must get to the nomount state and re-create the controlfile (something you said you'd already tried). The re-creation of the controlfile uses a SQL command and script which I hope you already have created using the backup controlfile to trace command. That script needs editing slightly in the way I've already indicated, and you'll get a bonus resetlogs, too.

If you *don't* have the backup to trace script, you are in deep trouble. It's only a SQL command, but the syntax is extremely fiddly, and getting it right depends entirely on you having excellent documentation for your database configuration (file locations, read only/read write state, tempfile knowledge etc etc). Failing that, a perfect photographic recall of the details would do the job.

But if you want a one word answer to your final question, it's this: NO.

A database requires a control file. Your backup doesn't have a copy of it. Therefore, as it stands, the backup cannot be used to effect a recovery.

Regards
HJR "xueyang" <xueyangy_at_singnet.com.sg> wrote in message news:aemseq$pgd$1_at_coco.singnet.com.sg...
> Thanks for the reply,
> Ok, Let me make my question clearer.
> I have a cold backup of my production(only all the dbf files and no
control
> file and online redo log file),
> Now my production server is gone(become nothing), can i use that backup to
> restore my production db?
>
> Regards,
> "Howard J. Rogers" <dba_at_hjrdba.com> wrote in message
> news:aempmo$6lp$1_at_lust.ihug.co.nz...
> >
> > "xueyang" <xueyangy_at_singnet.com.sg> wrote in message
> > news:aem9j7$nib$1_at_coco.singnet.com.sg...
> > > Hi,
> > >
> > > I backuped our production db( all the dbf files), but i didn't backup
> the
> > > control file and online redo log. this db is running under
noarchivelog
> > > mode.
> > > Now i try to restore this db on another server with this version of
> > > backup(all the dbf files , no control file and redo log file), and i
met
> > > some problem.
> > > I can't startup the db due to no control file. when i tried to create
> > > control file, it told me no redo log file.
> > > Anyone has any idea about this? thanks in advance.
> > >
> >
> > Yup. My fatuous idea is that you should read up a bit on backup and
> recovery
> > principles. For example, because you are not running in archivelog mode,
> you
> > are doing closed database backups (I hope). When the database is closed
it
> > is perfectly permissible to backup the online redo logs (because they
are
> > now actually offline and as cold as an iceberg without a woolly jumper).
> It
> > is also, as a matter of practical neccessity, almost mandatory to backup
> the
> > control file.
> >
> > That said, you said you tried to create a new controlfile, which
> presumably
> > means you know how to do an 'alter database backup controlfile to trace'
> and
> > have therefore got a 'create controlfile' script.
> >
> > Make a slight amendment to that script: on the top line, where it says
> > 'create controlfile... noresetlogs', change it to read 'resetlogs'.
> >
> > Lower down (near the end), there's a line that says 'recover database'
> > followed by 'alter database open'. Change that last line to 'alter
> database
> > open resetlogs'. Now run the script as per usual, and the resetlogs will
> > cause all the redo logs specified in the bulk of the script to be
> *created*
> > for you.
> >
> > Regards
> > HJR
> >
> >
> >
> >
> > > Regards,
> > >
> > >
> > >
> >
> >
>
>
Received on Tue Jun 18 2002 - 04:02:13 CDT