Dba_rollback_segs in Oracle 11.1.0.7.0

Question

Hi.
As far i Know Oracle 10 and 11 g uses undo segments instead of roll back segments.
Then what is the purpose of dba_rollback_segs in 11g.
SQL> select * from v$version;
BANNER
Oracle Database 11g Enterprise Edition Release 11.1.0.7.0 - 64bit Production
PL/SQL Release 11.1.0.7.0 - Production
CORE    11.1.0.7.0      Production
TNS for Linux: Version 11.1.0.7.0 - Production
NLSRTL Version 11.1.0.7.0 - ProductionI can able to query fro this table
SQL> select SEGMENT_NAME,TABLESPACE_NAME,STATUS from dba_rollback_segs
2  where SEGMENT_NAME='_SYSSMU72$';
SEGMENT_NAME                   TABLESPACE_NAME                STATUS
_SYSSMU72$                     APPS_UNDOTS1                   ONLINEPlease clarify .
Thanks in Advance
Edited by: Vijay.Cherukuri on Jun 25, 2012 1:10 PM

Answer 1

Hi Srini ,
Thanks for you reply.
As per MOS DOC its says " ROLLBACK segments are called UNDO segments when AUM is enabled. " .
That means When we have AUM enabled . there no difference between undo and rollback segments (both are same ) . Only difference is we can not manage them manually as we can in version 8i and 9i. They are managed by RDBMS in 10 and 11g when AUM enabled.
-- If AUM is disabled then there are no rollback segments in 10 and 11g ,we have only undo segs ? is it correct ?
Please clarify
Thanks