Re: system tablespace rollback segment is corrupted in 8i or 9i

DA Morgan wrote:
> fitzjarrell_at_cox.net wrote:
>
> > I'm not saying it, the Oracle documentation is stating this:
> >
> > "The Rollback Segment SYSTEM
> > Oracle creates an initial rollback segment called SYSTEM whenever a
> > database is created. This segment is in the SYSTEM tablespace and uses
> > that tablespace's default storage parameters. You cannot drop the
> > SYSTEM rollback segment. An instance always acquires the SYSTEM
> > rollback segment in addition to any other rollback segments it needs.
> >
> > With multiple rollback segments, Oracle tries to use the SYSTEM
> > rollback segment only for special system transactions and distributes
> > user transactions among other rollback segments. If there are too many
> > transactions for the nonSYSTEM rollback segments, then Oracle uses the
> > SYSTEM segment as necessary. In general, after database creation,
> > create at least one additional rollback segment in the SYSTEM
> > tablespace."
> >
> > I've recently added an extra SYSTEM rollback segment in our test
> > environments, to see what impact, negative or positive, it creates. I
> > can understand the logic of doing so; a second SYSTEM rollback segment
> > would allow an otherwise unavailable database to be mounted and opened,
> > as the second SYSTEM rollback segment can be used, so it could prevent
> > downtime in the event a SYSTEM rollback segment does become corrupted
> > or unusable.
> >
> >
> > David Fitzjarrell
>
> The link please ... the link. I want to capture this for my students.
>
> Thanks.
> --
> Puget Sound Oracle Users Group

http://download-east.oracle.com/docs/cd/B10501_01/server.920/a96524/b_deprec.htm

David Fitzjarrell Received on Wed Sep 06 2006 - 09:44:49 CDT