现场无法保留处理日志记录下来，记忆中写出来，给自己一个思路的提示
一个开发库启动时候报undo出现问题，环境是Oracle 10.2.0.5和aix 5308
启动数据库，提示undo损坏
ORA-01157: cannot identify/lock data file 4 - see DBWR trace file
ORA-01110: data file 4: '/u01/app/oracle/oradata/YONGDB/undotbs01.dbf'
查看：
select file#,name,status from v$datafile;
结果: undotbs1 表空间的状态是media recover.
因此先删除undo的数据文件，打开数据库
SQL> alter database datafile '/oradata/gyldb/undotbs01.dbf' offline for drop;
Database altered.
SQL> alter database open;
Database altered.
创建新的undo表空间
SQL> create undo tablespace UNDOTBS2 datafile '/oradata/gyldb/undotbs021.dbf' size 500m;
Tablespace created.
SQL> alter system set undo_tablespace=UNDOTBS2;
System altered.
然后删除有问题的undo表空间
SQL> drop tablespace UNDOTBS1 including contents and datafiles;
drop tablespace UNDOTBS1 including contents and datafiles
*
ERROR at line 1:
ORA-01548: active rollback segment '_SYSSMU1_3638931391$' found, terminate
dropping tablespace
select SEGMENT_NAME,TABLESPACE_NAME,STATUS from dba_rollback_segs
create pfile='/home/oracle/yd.ora' from spfile
关闭数据库，修还pfile，在加上
_CORRUPTED_ROLLBACK_SEGMENTS=(_SYSSMU2_3033359625$',_SYSSMU9_2087597455$,_SYSSMU8_2755301871$,_SYSSMU7_700714424$,_SYSSMU6_3548494004$,_SYSSMU5_1738828719$ ,_SYSSMU4_286801445$,_SYSSMU3_2670780772$,_SYSSMU2_3033359625$）
SQL> drop tablespace undotbs1 including contents and datafiles;
drop tablespace undotbs1 including contents and datafiles
*
ERROR at line 1:
ORA-01548: active rollback segment '_SYSSMU10_3267518184$' found, terminate dropping tablespace
继续检查
SQL> select SEGMENT_NAME,TABLESPACE_NAME,STATUS from dba_rollback_segs;
SEGMENT_NAME TABLESPACE_NAME STATUS
------------------------------------------------------------ ------------------------------------------------------------ --------------------------------
SYSTEM SYSTEM ONLINE
_SYSSMU10_3267518184$ UNDOTBS1 NEEDS RECOVERY
_SYSSMU24_1022883919$ UNDOTBS2 ONLINE
_SYSSMU23_1498951573$ UNDOTBS2 ONLINE
_SYSSMU22_1897326838$ UNDOTBS2 ONLINE
_SYSSMU21_3263997952$ UNDOTBS2 ONLINE
_SYSSMU16_4093610673$ UNDOTBS2 ONLINE
_SYSSMU15_758499186$ UNDOTBS2 ONLINE
_SYSSMU14_3461607053$ UNDOTBS2 ONLINE
_SYSSMU13_3534707649$ UNDOTBS2 ONLINE
_SYSSMU12_2563089079$ UNDOTBS2 ONLINE
SEGMENT_NAME TABLESPACE_NAME STATUS
------------------------------------------------------------ ------------------------------------------------------------ --------------------------------
_SYSSMU11_3918295226$ UNDOTBS2 ONLINE
重新关闭，在pfile后面继续添加：
_OFFLINE_ROLLBACK_SEGMENTS=(_SYSSMU10_3267518184$)
或者尝试
ALTER ROLLBACK SEGMENT '_SYSSMU10_3267518184$' OFFLINE;
DROP ROLLBACK SEGMENT '_SYSSMU10_3267518184$';
重新以pfile启动后删除
drop tablespace undotbs1 including contents and datafiles;
然后创建新的默认的undotbs1
create undo tablespace UNDOTBS1 datafile '/oradata/gyldb/undotbs01.dbf' size 10000m reuse;
alter system set undo_tablespace=UNDOTBS1;
以下略
问题遂解决