Re: Simple question: remove a a datafile from a tablespace

As Winnie noted the "offline drop" will allow one to open the database if the database is missing a datafile. One other note... the "offline drop" only prevents Oracle from checking for the existence of the datafile and doing it's usual verification of the file. The tablespace that uses the datafile will still reference this datafile. If Oracle extends an objects it very well may attempt to allocate an extent in the datafile that has been dropped. In addition, running SQL that references extents in the datafile will also result in I/O errors. The "offline drop" does not drop a datafile from a tablespace. Only a DROP TABLESPACE will remove datafiles from the database.

In article <6t7k2s$4d_at_sjx-ixn10.ix.netcom.com>,   "Winnie Liu" <oracle_dba_at_zdnetmail.com> wrote:
> The offline drop command is to put the datafile on hold and tell Oracle that
> the datafile is going to be recovered later (or drop later). It is a way to
> open a database which had a corrupted datafile but running in the noarchive
> log mode. This is the only way to open the database even when you have a
> corrputed datafile under the noarchive log mode. For archive log, the format
> is "offline" only.
>
> Check the Oracle backup and recovery workshop from Oracle press.. one of the
> best book for recovery.
>
> Winnie
>
> Andy Hardy wrote in message <01bddb8d$a92ad470$c70c400a_at_cms_bssup>...
> >
> >
> >Winnie Liu <oracle_dba_at_zdnetmail.com> wrote in article
> ><6sq0pp$bul_at_dfw-ixnews6.ix.netcom.com>...
> >> There is no safe way to remove a datafile from a tablespace. Because
> >> whenever you add a datafile to the database, even though you know that
> >> particular datafile is empty, ORacle had already added this file to its
> >list
> >> when they search for free blocks. So, you cannot use offline drop. The
> >only
> >> way is to export all the object in that tablespace and then reimport it
> >back
> >>
> >That's weird... so what is the offline drop command for?
> >
> >Andy
>
>

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