Re: coping the control file

a question is embedded.

regards,

:) ATTA In article <39dd0d9d_at_news.iprimus.com.au>,   "Howard J. Rogers" <howardjr_at_www.com> wrote:
>
> "Keth Slaton" <kslaton_at_newsguy.com> wrote in message
> news:mqontssg1s7siqd6dj7k4t322q0opu3vuk_at_4ax.com...
> > Could there ever be a competent newbe question? Oh well
> >
> > My question is this when working with control files I understand
 that
> > I must use the alter database command to create a human readable
 text
> > file. But would it be possible to just copy the file from one
> > directory to another? Oh and would I need to do this durning system
> > maintenance or could I copy the file at anytime.
> >
> > Thanks in advance
>
> If the database is up and running, then no, you can't just copy the
 control
> file -it will be internally inconsistent, and unuseable. That's why
 the
> command 'alter database backup controlfile
 to 'c:\overthere\control.bkp' was
> invented -because Oracle is producing the copy, it is guaranteed
 consistent.
> However, that command can indeed be issued at any time of the day or
 night.
>
> If the database is fully shut down, then you can copy it as though it
 were
> any other file on your disk.
>
> But the real issue is this: copying the controlfile is fine for when
 you
> want to start out mirroring. After that, binary versions of the
 controlfile
> are a royal pain in the butt to work with. When you come to use an
 old
> binary copy of the controlfile to recover a database that has lost
 all its
> originals, you will be forced to open the database with a resetlogs -
 and
> that means, nasically, that all prior backups and all prior archives
 (if
> you're taking them) are rendered instantly worthless -they now relate
 to a
> prior incarnation of the database, and can't be used for the present
> incarnation (except under extraordinary circumstances).

Just wondering what these 'extraordinary circumstances' could be?

Resetlogs is,
> therefore, a VERY expensive option, and a binary image of the
 controlfile
> will guarantee one.
>
> The text script you mention (the 'backup controlfile to trace' trace
 file)
> is much the preferred method of recovering from total controlfile
 loss,
> provided you keep it up to date... using it, all required copies of
 the
> controlfile are regenerated from scratch, with the system forcing the
> highest SCN found amongst the datafiles into the header of the new
> controlfiles. Thus, there is no resetlogs, and all prior backups and
> archives remain entirely useable.
>
> Regards
> HJR
>
>

--

getting the meanin' of data...


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