Oralce 11g 在啟動資料庫時，出現ORA-01113: file 3 needs media recovery

今天嘗試在UNDO Datafile刪除之後（只是把檔案更名而已）的還原方式，
試了幾種不用隱藏的參數*._offline_rollback_segments的方法都失敗，
在恢後UNDO Datafile之後開啟資料庫，卻出現了needs media recovery的訊息。

SQL> startup
ORACLE instance started.

Total System Global Area  456146944 bytes
Fixed Size    1344840 bytes
Variable Size  394267320 bytes
Database Buffers   54525952 bytes
Redo Buffers    6008832 bytes
Database mounted.
ORA-01113: file 3 needs media recovery
ORA-01110: data file 3: '/home/oracle/app/oracle/oradata/orcl/undotbs01.dbf'

試著RECOVER資料庫
SQL> recover database;
ORA-00279: change 9613767 generated at 05/11/2014 20:42:31 needed for thread 1
ORA-00289: suggestion : /backup/archive/orcl_1_428_701609923.arc
ORA-00280: change 9613767 for thread 1 is in sequence #428

我是輸入AUTO
Specify log: {<RET>=suggested | filename | AUTO | CANCEL}
AUTO

ORA-00279: change 9638206 generated at 05/11/2014 22:17:58 needed for thread 1
ORA-00289: suggestion : /backup/archive/orcl_1_429_701609923.arc
ORA-00280: change 9638206 for thread 1 is in sequence #429
ORA-00279: change 9658236 generated at 05/11/2014 22:20:19 needed for thread 1
（…略）

Log applied.
Media recovery complete.

完成RECOVER之後，將資料庫啟動到OPEN的模式
SQL> alter database open;

Database altered.

到此就完成了。