I want to know the meaning of status column of dba_undo_extents . I have seen 3 possible values - ACTIVE, EXPIRED, UNEXPIRED. What are the meanings ? I am trying to guess - ACTIVE means that this undo segment contains active transactions - EXPIRED means that this segment is not rqeuired at all ( considering Undo retention period )- UNEXPIRED means that this segment does not contain any active transactions but it contains transactions which are still required for Flashback option ( considering Undo retention period ).
The version of the database is 9i rel 2.
Am I right ?