Re: Oracle9iAS - Make sure there is at least one online non-system rollback segment?

Alan wrote:

> Thanks - but "create rollback segment ROLLBACKSEG;" failed with an
> "ORA-30019: Illegal rollback Segment operation in Automatic Undo
> mode".
>
> Alternatively - I've been able to issue:
>
> SQL> create undo tablespace undo_tbs1 datafile
> /var/opt/oracle/undoTablespace/undo_tbs1.dat' size 100M;
> SQL> Alter system set undo_tablespace = undo_tbs1;
>
>
> not sure where the standard/correct place to put these files (or even
> the standard filename extension) on Solaris, so I've dumped it there
> for now.
>

STarting Oracle9i - you can run your database in either 'UNDO' or 'ROLLABCK SEGMENT' mode.

Basically UNDO SEGMENTS are 'automated rollback segments' - effectively same format and definitely same purpose as rollback segment, but managed by the database instead of the DBA.

It's an 'either - or' situation. If you have UNDO, you can't have traditional ROLLBACK. Also, whereas the ROLLBACK mechanism allowed multiple segments placed where you want, you only have one UNDO 'segment' in an UNDO tablespace all by itself.

The docco needs to be updates to say 'non-system rollback segment or an active undo segment/tablespace'.

/Hans Received on Thu Sep 30 2004 - 17:45:44 CDT