如何删除回滚段状态为NEEDS RECOVERY的undo表空间

环境：RHEL 6.4 + Oracle 11.2.0.4
背景：备份恢复的测试库在一次不完全恢复后，没有来及做有效的全备，又一次数据库故障导致数据库无法正常open。
只能离线部分数据文件打开数据库，其中包含undo表空间数据文件。
适用场景：无有效备份，可以丢失数据，删除回滚段状态为NEEDS RECOVERY的undo表空间。

一、数据库当前情况

1.1 故障现象

1.2 查看数据文件的状态

1.3 尝试online数据文件失败

二、删除损坏数据文件所在表空间

2.1 普通数据文件4所在的users表空间可以直接删除

2.2 undo数据文件3所在的undotbs1表空间尝试删除

2.3 undo数据文件3所在的undotbs1表空间删除方法

一、数据库当前情况

1.1 故障现象

open resetlogs 打开数据库报错ORA-01152，ORA-01110，将报错的数据文件offline，先打开数据库。
SQL> alter database open resetlogs;
alter database open resetlogs
*
ERROR at line 1:
ORA-01152: file 3 was not restored from a sufficiently old backup
ORA-01110: data file 3:
'/u02/oracle/JINGYU/datafile/o1_mf_undotbs1_bwp19o3n_.dbf'

SQL> alter database datafile 3 offline;
Database altered.

SQL>  alter database open resetlogs;
 alter database open resetlogs
*
ERROR at line 1:
ORA-01152: file 4 was not restored from a sufficiently old backup
ORA-01110: data file 4: '/u02/oracle/JINGYU/datafile/o1_mf_users_bwp1b12d_.dbf'

SQL> alter database datafile 4 offline;
Database altered.

SQL>  alter database open resetlogs;
Database altered.

1.2 查看数据文件的状态

数据文件3，4OFFLINE。其中数据文件3是undo表空间的数据文件。
SQL> set linesize 150
SQL> col file_name for a56
SQL> select FILE_ID, FILE_NAME, TABLESPACE_NAME, BYTES/1024/1024 "MB", MAXBYTES/1024/1024/1024 "GB", AUTOEXTENSIBLE, STATUS, ONLINE_STATUS from dba_data_files;

  FILE_ID FILE_NAME                                                TABLESPACE_NAME                        MB        GB AUT STATUS    ONLINE_
---------- -------------------------------------------------------- ------------------------------ ---------- ---------- --- --------- -------
        1 /u02/oracle/JINGYU/datafile/o1_mf_system_bwp198r7_.dbf  SYSTEM                                700 31.9999847 YES AVAILABLE SYSTEM
        2 /u02/oracle/JINGYU/datafile/o1_mf_sysaux_bwp19hl8_.dbf  SYSAUX                                600 31.9999847 YES AVAILABLE ONLINE
        3 /u02/oracle/JINGYU/datafile/o1_mf_undotbs1_bwp19o3n_.dbf UNDOTBS1                                                AVAILABLE OFFLINE
        4 /u02/oracle/JINGYU/datafile/o1_mf_users_bwp1b12d_.dbf    USERS                                                    AVAILABLE OFFLINE
        5 /u02/oracle/JINGYU/datafile/o1_mf_dbs_d_ji_bwp4r7cm_.dbf DBS_D_JINGYU                          100 31.9999847 YES AVAILABLE ONLINE

1.3 尝试online数据文件失败
SQL> alter database datafile 3 online;
alter database datafile 3 online
*
ERROR at line 1:
ORA-01190: control file or data file 3 is from before the last RESETLOGS
ORA-01110: data file 3: '/u02/oracle/JINGYU/datafile/o1_mf_undotbs1_bwp19o3n_.dbf'

SQL> alter database datafile 4 online;
alter database datafile 4 online
*
ERROR at line 1:
ORA-01190: control file or data file 4 is from before the last RESETLOGS
ORA-01110: data file 4: '/u02/oracle/JINGYU/datafile/o1_mf_users_bwp1b12d_.dbf'

二、删除损坏数据文件所在表空间

2.1 普通数据文件4所在的users表空间可以直接删除
SQL> drop tablespace users including contents and datafiles;
drop tablespace users including contents and datafiles
*
ERROR at line 1:
ORA-12919: Can not drop the default permanent tablespace

SQL> alter database default tablespace DBS_D_JINGYU;

Database altered.

SQL> drop tablespace users including contents and datafiles;

Tablespace dropped.

SQL> select FILE_ID, FILE_NAME, TABLESPACE_NAME, BYTES/1024/1024 "MB", MAXBYTES/1024/1024/1024 "GB", AUTOEXTENSIBLE, STATUS, ONLINE_STATUS from dba_data_files;

  FILE_ID FILE_NAME                                                TABLESPACE_NAME                        MB        GB AUT STATUS    ONLINE_
---------- -------------------------------------------------------- ------------------------------ ---------- ---------- --- --------- -------
        1 /u02/oracle/JINGYU/datafile/o1_mf_system_bwp198r7_.dbf  SYSTEM                                700 31.9999847 YES AVAILABLE SYSTEM
        2 /u02/oracle/JINGYU/datafile/o1_mf_sysaux_bwp19hl8_.dbf  SYSAUX                                600 31.9999847 YES AVAILABLE ONLINE
        3 /u02/oracle/JINGYU/datafile/o1_mf_undotbs1_bwp19o3n_.dbf UNDOTBS1                                                AVAILABLE OFFLINE
        5 /u02/oracle/JINGYU/datafile/o1_mf_dbs_d_ji_bwp4r7cm_.dbf DBS_D_JINGYU                          100 31.9999847 YES AVAILABLE ONLINE

2.2 undo数据文件3所在的undotbs1表空间尝试删除

尝试删除直接报错ORA-01548.同时无法正常关闭数据库，无法删除活动的回滚段。具体如下：

2.2.1 创建新的undo表空间undotbs2并设置为默认的undo表空间
SQL> create undo tablespace undotbs2; 

Tablespace created.

SQL> show parameter undo

NAME                                TYPE        VALUE
------------------------------------ ----------- ------------------------------
undo_management                      string      AUTO
undo_retention                      integer    900
undo_tablespace                      string      UNDOTBS1

SQL> alter system set undo_tablespace='undotbs2';

System altered.

SQL> show parameter undo

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

2.2.2 删除旧的undotbs1表空间失败
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_1401565358$' found, terminate dropping tablespace

2.2.3 查看回滚段的状态，确定undotbs1表空间的回滚段状态都是NEEDS RECOVERY
SQL> select segment_id, segment_name,status,tablespace_name from dba_rollback_segs where status not in ('ONLINE','OFFLINE');

SEGMENT_ID SEGMENT_NAME                  STATUS          TABLESPACE_NAME
---------- ------------------------------ ---------------- ------------------------------
        1 _SYSSMU1_1401565358$          NEEDS RECOVERY  UNDOTBS1
        2 _SYSSMU2_3125365238$          NEEDS RECOVERY  UNDOTBS1
        3 _SYSSMU3_1538315859$          NEEDS RECOVERY  UNDOTBS1
        4 _SYSSMU4_1640924022$          NEEDS RECOVERY  UNDOTBS1
        5 _SYSSMU5_2892967416$          NEEDS RECOVERY  UNDOTBS1
        6 _SYSSMU6_3276341082$          NEEDS RECOVERY  UNDOTBS1
        7 _SYSSMU7_387283697$            NEEDS RECOVERY  UNDOTBS1
        8 _SYSSMU8_2299136685$          NEEDS RECOVERY  UNDOTBS1
        9 _SYSSMU9_909303715$            NEEDS RECOVERY  UNDOTBS1
        10 _SYSSMU10_1695440836$          NEEDS RECOVERY  UNDOTBS1

10 rows selected.

2.2.4 此时正常关库会提示失败
SQL> select file#,status from v$datafile;

    FILE# STATUS
---------- -------
        1 SYSTEM
        2 ONLINE
        3 OFFLINE
        4 ONLINE
        5 ONLINE

SQL> shutdown immediate;
ORA-00376: file 3 cannot be read at this time
ORA-01110: data file 3: '/u02/oracle/JINGYU/datafile/o1_mf_undotbs1_bwp19o3n_.dbf'

2.2.5 此时删除回滚段也会提示失败

目前数据库无有效备份，需要把这些NEEDS RECOVERY的undo rollback segs删除
SQL> drop  rollback segment "_SYSSMU10_1695440836$";
drop  rollback segment "_SYSSMU10_1695440836$"
*
ERROR at line 1:
ORA-30025: DROP segment '_SYSSMU10_1695440836$' (in undo tablespace) not allowed

2.3 undo数据文件3所在的undotbs1表空间删除方法

2.3.1 修改pfile文件这几行内容

其中_offline_rollback_segments参数中的回滚段的名字在上面查到过。
*.undo_management='MANUAL'
*._offline_rollback_segments=(_SYSSMU1_1401565358$,_SYSSMU2_3125365238$,_SYSSMU3_1538315859$,_SYSSMU4_1640924022$,_SYSSMU5_2892967416$,_SYSSMU6_3276341082$,_SYSSMU7_387283697$,_SYSSMU8_2299136685$,_SYSSMU9_909303715$,_SYSSMU10_1695440836$)
#*.undo_tablespace='undotbs2'

2.3.2 使用pfile文件启动数据库
SQL> startup pfile='/tmp/pfile.ora';
ORACLE instance started.

Total System Global Area 1620115456 bytes
Fixed Size                  2253704 bytes
Variable Size            989858936 bytes
Database Buffers          620756992 bytes
Redo Buffers                7245824 bytes
Database mounted.
Database opened.

2.3.3 删除回滚段成功
SQL>  drop rollback segment "_SYSSMU10_1695440836$";

Rollback segment dropped.

2.3.4 删除回滚表空间undotbs1成功
SQL> drop tablespace undotbs1 including contents and datafiles;

Tablespace dropped.

2.3.5 此时查询数据库的相关信息
SQL>  select segment_id, segment_name,status,tablespace_name from dba_rollback_segs where status not in ('ONLINE','OFFLINE')
  2  ;

no rows selected

SQL> select FILE_ID, FILE_NAME, TABLESPACE_NAME, BYTES/1024/1024 "MB", MAXBYTES/1024/1024/1024 "GB", AUTOEXTENSIBLE, STATUS, ONLINE_STATUS from dba_data_files;

  FILE_ID FILE_NAME                                                TABLESPACE_NAME                        MB        GB AUT STATUS    ONLINE_
---------- -------------------------------------------------------- ------------------------------ ---------- ---------- --- --------- -------
        1 /u02/oracle/JINGYU/datafile/o1_mf_system_bwp198r7_.dbf  SYSTEM                                700 31.9999847 YES AVAILABLE SYSTEM
        2 /u02/oracle/JINGYU/datafile/o1_mf_sysaux_bwp19hl8_.dbf  SYSAUX                                600 31.9999847 YES AVAILABLE ONLINE
        4 /u02/oracle/JINGYU/datafile/o1_mf_undotbs2_bwqxbnxo_.dbf UNDOTBS2                              100 31.9999847 YES AVAILABLE ONLINE
        5 /u02/oracle/JINGYU/datafile/o1_mf_dbs_d_ji_bwp4r7cm_.dbf DBS_D_JINGYU                          100 31.9999847 YES AVAILABLE ONLINE

发现此时一切数据文件正常,此时已经可以正常关库
SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.

2.3.6 以spfile正常启动数据库，检查一切正常
SQL> startup
ORACLE instance started.

Total System Global Area 1620115456 bytes
Fixed Size                  2253704 bytes
Variable Size            989858936 bytes
Database Buffers          620756992 bytes
Redo Buffers                7245824 bytes
Database mounted.
Database opened.
SQL> show parameter undo

NAME                                TYPE        VALUE
------------------------------------ ----------- ------------------------------
undo_management                      string      AUTO
undo_retention                      integer    900
undo_tablespace                      string      undotbs2
SQL> set linesize 150
SQL> col file_name for a56
SQL> select FILE_ID, FILE_NAME, TABLESPACE_NAME, BYTES/1024/1024 "MB", MAXBYTES/1024/1024/1024 "GB", AUTOEXTENSIBLE, STATUS, ONLINE_STATUS from dba_data_files;

  FILE_ID FILE_NAME                                                TABLESPACE_NAME                        MB        GB AUT STATUS    ONLINE_
---------- -------------------------------------------------------- ------------------------------ ---------- ---------- --- --------- -------
        1 /u02/oracle/JINGYU/datafile/o1_mf_system_bwp198r7_.dbf  SYSTEM                                700 31.9999847 YES AVAILABLE SYSTEM
        2 /u02/oracle/JINGYU/datafile/o1_mf_sysaux_bwp19hl8_.dbf  SYSAUX                                600 31.9999847 YES AVAILABLE ONLINE
        4 /u02/oracle/JINGYU/datafile/o1_mf_undotbs2_bwqxbnxo_.dbf UNDOTBS2                              100 31.9999847 YES AVAILABLE ONLINE
        5 /u02/oracle/JINGYU/datafile/o1_mf_dbs_d_ji_bwp4r7cm_.dbf DBS_D_JINGYU                          100 31.9999847 YES AVAILABLE ONLINE

最后，立即对当前恢复好的数据库做一个全备吧。