Oracle FAQ Your Portal to the Oracle Knowledge Grid
HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US
 

Home -> Community -> Usenet -> c.d.o.server -> Re: Backup question - temp tablespaces

Re: Backup question - temp tablespaces

From: Howard J. Rogers <howardjr_at_www.com>
Date: Wed, 14 Feb 2001 07:54:31 +1100
Message-ID: <3a899f09@news.iprimus.com.au>

Rollback segments live in rollback tablespaces (or ought to).

Rollback segments are real segments -permanent objects, that is. They cannot reside in proper temporary tablespace (just like nothing else can).

You are correct that recoveries get very interesting if there are no rollback segments, but the absence of temporary tablespace is not a concern at that particular time.

Regards
HJR "Syltrem" <syltrem_at_videotron.ca> wrote in message news:Kzfi6.5316$Iu3.103201_at_weber.videotron.net...
> Thanks for the info.
>
> Is this still valid for online backups, in the case you have to restore
 all
> the db after a disaster, say? Won't Oracle sometimes want to see the temp
> segments to rollback transactions or something like this?
>
> --
>
> Sytrem
> http://pages.infinit.net/syltrem
>
> "Howard J. Rogers" <howardjr_at_www.com> a écrit dans le message news:
> Jc3i6.174$305.62763_at_inet16.us.oracle.com...
> > The 'create datafile blah as blah1' syntax is specifically designed for
> > re-creating a tablespace (well, a datafile really) that is subject to
 media
> > failure but which has never been included in a previous backup.
 Provided
> > ALL redo since time of the datafile's creation is available, the thing
 can
> > still be recovered -but the redo needs to be applied to a new, blank
> > datafile which looks to the database like an exact copy of the old one.
> >
> > In short, that bit of syntax has absolutely nothing to do with
 recovering
 or
> > backing up TEMP tablespaces.
> >
> > The usual recommendation for temp datafiles is to do exactly what you
 went
> > on to do. Oracle will always notice ANY missing datafiles (whether of
 type
> > TEMPORARY or PERMANENT), and will prompt you to perform recovery on it.
 The
> > thing about TEMP stuff is that you ignore the prompt: you just offline
 drop
> > the relevant datafile, open what's left of the database, drop the TEMP
> > tablespace in its entirety, and create a brand new one.
> >
> > So: short answer is (1) don't back up datafiles associated with a
 temporary
> > tablespace. (2) Don't recreate them before opening the database (3)
> > recreate the entire tablespace once the rest of the database is up and
> > running
> >
> > Regards
> > HJR
> >
> >
> > "Syltrem" <syltrem_at_videotron.ca> wrote in message
> > news:64Wh6.3517$Iu3.61069_at_weber.videotron.net...
> > > Hello!
> > >
> > > I am testing a db restore from cold backup but... I have not backed up
 the
> > > TEMP tablespace. Instead I have a script that says:
> > > ALTER DATABASE CREATE DATAFILE 'xyz' AS 'XYZ';
> > >
> > > Since the temp datafile is a TEMPORARY tablespace content, there is
 nothing
> > > in there that needs backing up and I figured I could re-create the
 file
> > > before ALTER DATABASE OPEN.
> > >
> > > It did not work as expected. I received the message that the file
 needed
> > > recovery. Why? I was finally able to do an ALTER DATABASE DATAFILE
 'xx'
> > > OFFLINE DROP and ALTER DATABASE OPEN, after which I dropped the temp
> > > tablespace and recreated it.
> > >
> > > So I guess my method is not so good, and the question is:
> > > How would you go about not backing up the temporary tablespaces
 (datafiles)?
> > >
> > > Thanks!
> > >
> > > --
> > >
> > > Sytrem
> > > http://pages.infinit.net/syltrem
> > >
> > >
> > >
> >
> >
>
>
Received on Tue Feb 13 2001 - 14:54:31 CST

Original text of this message

HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US