undo_management设置与隐含参数*._offline_rollback_segments和*._corru

一环境：oracle版本：10.2.0.1.0当前undo表空间：SQLshowparameterundo;NAME&n..

一 环境：
oracle版本：10.2.0.1.0
当前undo表空间：
SQL> show parameter undo;

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
undo_management                      string      AUTO
undo_retention                       integer     900
undo_tablespace                      string      UNDOTBS4
当前系统内的还原表空间：
SQL> select tablespace_name,status from dba_tablespaces where tablespace_name like '%UNDO%';

TABLESPACE_NAME                STATUS
------------------------------ ---------
UNDOTBS4                       ONLINE
当前undo表空间undotbs4的所有回滚段状况如下：
SQL> select * from v$rollname; （查询当前系统活动回滚段）

       USN NAME
---------- ----------------------------------------
         0 SYSTEM
         1 _SYSSMU1$
         2 _SYSSMU2$
         3 _SYSSMU3$
         4 _SYSSMU4$
         5 _SYSSMU5$
         6 _SYSSMU6$
         7 _SYSSMU7$
         8 _SYSSMU8$
         9 _SYSSMU9$
        11 _SYSSMU11$

11 rows selected.

SQL> select segment_id,segment_name,tablespace_name,status from dba_rollback_segs;（查询系统内所有回滚段信息）

SEGMENT_ID SEGMENT_NAME                   TABLESPACE_NAME                STATUS
---------- ------------------------------ ------------------------------ ----------------
         0 SYSTEM                         SYSTEM                         ONLINE
         1 _SYSSMU1$                      UNDOTBS4                       ONLINE
         2 _SYSSMU2$                      UNDOTBS4                       ONLINE
         3 _SYSSMU3$                      UNDOTBS4                       ONLINE
         4 _SYSSMU4$                      UNDOTBS4                       ONLINE
         5 _SYSSMU5$                      UNDOTBS4                       ONLINE
         6 _SYSSMU6$                      UNDOTBS4                       ONLINE
         7 _SYSSMU7$                      UNDOTBS4                       ONLINE
         8 _SYSSMU8$                      UNDOTBS4                       ONLINE
         9 _SYSSMU9$                      UNDOTBS4                       ONLINE
        11 _SYSSMU11$                     UNDOTBS4                       ONLINE

11 rows selected.