undo 表空間切換

SQL> show parameter undo

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
undo_management                      string      AUTO
undo_retention                       integer     900
undo_tablespace                      string      UNDOTBS1
SQL> col name for a58


SQL> select name from v$datafile;

NAME
----------------------------------------------------------
/u01/app/oracle/oradata/ora10g/system01.dbf
/u01/app/oracle/oradata/ora10g/undotbs01.dbf
/u01/app/oracle/oradata/ora10g/sysaux01.dbf
/u01/app/oracle/oradata/ora10g/users01.dbf
/u01/app/oracle/oradata/ora10g/example01.dbf

SQL> create undo tablespace undotbs2 datafile '/u01/app/oracle/oradata/ora10g/undotbs2' size 51200MB autoextend off;

SQL> alter system set undo_tablespace='undotbs2' scope=both;

SQL> show parameter undo

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
undo_management                      string      AUTO
undo_retention                       integer     900
undo_tablespace                      string      undotbs2

SQL> select tablespace_name,segment_name,status from dba_rollback_segs;

TABLESPACE_NAME                SEGMENT_NAME                   STATUS
------------------------------ ------------------------------ ----------------
SYSTEM                         SYSTEM                         ONLINE

UNDOTBS1                       _SYSSMU10$                     OFFLINE
UNDOTBS1                       _SYSSMU9$                      OFFLINE
UNDOTBS1                       _SYSSMU8$                      OFFLINE
UNDOTBS1                       _SYSSMU7$                      OFFLINE
UNDOTBS1                       _SYSSMU6$                      OFFLINE
UNDOTBS1                       _SYSSMU5$                      OFFLINE
UNDOTBS1                       _SYSSMU4$                      OFFLINE
UNDOTBS1                       _SYSSMU3$                      OFFLINE
UNDOTBS1                       _SYSSMU2$                      OFFLINE
UNDOTBS1                       _SYSSMU1$                      OFFLINE

UNDOTBS2                       _SYSSMU20$                     ONLINE
UNDOTBS2                       _SYSSMU19$                     ONLINE
UNDOTBS2                       _SYSSMU18$                     ONLINE
UNDOTBS2                       _SYSSMU17$                     ONLINE
UNDOTBS2                       _SYSSMU16$                     ONLINE
UNDOTBS2                       _SYSSMU15$                     ONLINE
UNDOTBS2                       _SYSSMU14$                     ONLINE
UNDOTBS2                       _SYSSMU13$                     ONLINE
UNDOTBS2                       _SYSSMU12$                     ONLINE
UNDOTBS2                       _SYSSMU11$                     ONLINE

21 rows selected.

SQL> alter tablespace undotbs1 offline;
SQL> drop tablespace undotbs1 including contents and datafiles;