这个时候尝试使用前面的clear或者recover database都会报错，无法恢复，因为这个时候是需要做实例恢复的，那么什么时候需要实例恢复的判断依据，请参考另一篇文章(Oracle原理-----关于oracle实例恢复的前滚和回滚的理解)，报错如下：
首先尝试重建，当你尝试clear当前的日志组的时候，会报错提示是需要的!!!因为非一致性关闭确实需要使用丢失的active和current状态的redo来实例恢复!
首先启动数据库到mount状态
SQL> alter database clear logfile group 3;
alter database clear logfile group 3
*
ERROR at line 1:
ORA-01624: log 3 needed for crash recovery of instance stdb59 (thread 1)
ORA-00312: online log 3 thread 1:
'/data/u01/app/oracle/oradata/stdb59/redo03.log'
然后尝试recover database,结果肯定不可以，因为实例恢复需要的redo已经丢失!!
SQL> recover database until cancel;
ORA-00279: change 21959466 generated at 04/06/2019 21:15:45 needed for thread 1
ORA-00289: suggestion :
/data/u01/app/oracle/fast_recovery_area/STDB59/archivelog/2019_04_06/o1_mf_1_2_%
u_.arc
ORA-00280: change 21959466 for thread 1 is in sequence #2
Specify log: {<RET>=suggested | filename | AUTO | CANCEL}
CANCEL
ORA-01547: warning: RECOVER succeeded but OPEN RESETLOGS would get error below
ORA-01194: file 1 needs more recovery to be consistent
ORA-01110: data file 1: '/data/u01/app/oracle/oradata/stdb59/system01.dbf'
ORA-01112: media recovery not started
SQL> alter database open RESETLOGS;
alter database open RESETLOGS
ERROR at line 1:
ORA-01194: file 1 needs more recovery to be consistent
ORA-01110: data file 1: '/data/u01/app/oracle/oradata/stdb59/system01.dbf'
那么针对这种情况，恢复的方式如下：
使用一个隐含参数_allow_resetlogs_corruption强制启动数据库，设置此参数之后，在数据库Open过程中，Oracle会跳过某些一致性检查，从而使数据库可能跳过不一致状态，到达open数据库的目的
SQL> create pfile='/home/oracle/pfile.ora' from spfile;
File created.
然后在/home/oracle/pfile.ora添加上
*._allow_resetlogs_corruption=true
SQL> startup mount pfile='/home/oracle/pfile.ora';
SQL> recover database until cancel; #恢复丢失的redo文件
ORA-00279: change 21959471 generated at 04/06/2019 22:34:01 needed for thread 1
ORA-00289: suggestion :
/data/u01/app/oracle/fast_recovery_area/STDB59/archivelog/2019_04_06/o1_mf_1_2_%
u_.arc
ORA-00280: change 21959471 for thread 1 is in sequence #2
Specify log: {<RET>=suggested | filename | AUTO | CANCEL}
CANCEL
ORA-01547: warning: RECOVER succeeded but OPEN RESETLOGS would get error below
ORA-01194: file 1 needs more recovery to be consistent
ORA-01110: data file 1: '/data/u01/app/oracle/oradata/stdb59/system01.dbf'
ORA-01112: media recovery not started
幸运的话就可以直接以resetlogs方式open数据库了!
SQL> alter database open RESETLOGS;
Database altered.
如果遇到下面的错误，那么你就得重建控制文件了：
SQL> alter database open RESETLOGS;
alter database open RESETLOGS
*
ERROR at line 1:
ORA-01092: ORACLE instance terminated. Disconnection forced
ORA-00704: bootstrap process failure
ORA-00704: bootstrap process failure
ORA-00600: internal error code, arguments: [2662], [0], [21959484], [0],
[21959877], [4194545], [], [], [], [], [], []
Process ID: 13177
Session ID: 63 Serial number: 5
重建数据库控制文件
1)直接使用如下alter database backup controlfile这种会报错
SQL> alter database backup controlfile to trace as '/data/u01/control_rebuild.trc';
alter database backup controlfile to trace as '/data/u01/control_rebuild.trc'
*
ERROR at line 1:
ORA-16433: The database must be opened in read/write mode.
2)还可以使用如下特定的格式来重建，
查询数据库的redo 信息：
SQL> select GROUP#,MEMBER from v$logfile;
GROUP# MEMBER
3 /data/u01/app/oracle/oradata/stdb59/redo03.log
1 /data/u01/app/oracle/oradata/stdb59/redo01.log
查询数据库的datafile信息
SQL> select MEMBER from v$logfile;
MEMBER
--------------------------------------------------------------------------------
/data/u01/app/oracle/oradata/stdb59/redo03.log
/data/u01/app/oracle/oradata/stdb59/redo01.log
/data/u01/app/oracle/oradata/stdb59/redo04.log
/data/u01/app/oracle/oradata/stdb59/redo05.log
/data/u01/app/oracle/oradata/stdb59/redo06.log
/data/u01/app/oracle/oradata/stdb59/redo07.log
查出数据库字符集：
SQL> select userenv('language') nls_lang from dual;
NLS_LANG
----------------------------------------------------
AMERICAN_AMERICA.AL32UTF8
然后编辑出创建控制文件的脚本：注意这里的的testdb57为数据库(db_name),如果是adg转换成的主库，不要写db_unique_name
CREATE CONTROLFILE REUSE DATABASE 'testdb57' NORESETLOGS ARCHIVELOG
MAXLOGFILES 50
MAXLOGMEMBERS 5
MAXDATAFILES 100
MAXINSTANCES 8
MAXLOGHISTORY 226
LOGFILE
GROUP 3 '/data/u01/app/oracle/oradata/stdb59/redo03.log' SIZE 50M,
GROUP 1 '/data/u01/app/oracle/oradata/stdb59/redo01.log' SIZE 50M
DATAFILE
'/data/u01/app/oracle/oradata/stdb59/system01.dbf',
'/data/u01/app/oracle/oradata/stdb59/sysaux01.dbf',
'/data/u01/app/oracle/oradata/stdb59/undotbs01.dbf',
'/data/u01/app/oracle/oradata/stdb59/users01.dbf',
'/data/u01/app/oracle/oradata/stdb59/liuwenhe.dbf',
'/data/u01/app/oracle/oradata/stdb59/soe.dbf',
'/data/u01/app/oracle/oradata/stdb59/soe3.dbf'
CHARACTER SET AL32UTF8;
然后直接将数据库启动到nomount状态，执行创建脚本即可
SQL> startup nomount pfile='/home/oracle/pfile.ora';
ORACLE instance started.
Total System Global Area 1603411968 bytes
Fixed Size 2253664 bytes
Variable Size 1275071648 bytes
Database Buffers 318767104 bytes
Redo Buffers 7319552 bytes
CREATE CONTROLFILE REUSE DATABASE 'testdb57' NORESETLOGS ARCHIVELOG
MAXLOGFILES 50
MAXLOGMEMBERS 5
MAXDATAFILES 100
MAXINSTANCES 8
MAXLOGHISTORY 226
LOGFILE
GROUP 3 '/data/u01/app/oracle/oradata/stdb59/redo03.log' SIZE 50M,
GROUP 1 '/data/u01/app/oracle/oradata/stdb59/redo01.log' SIZE 50M
DATAFILE
'/data/u01/app/oracle/oradata/stdb59/system01.dbf',
'/data/u01/app/oracle/oradata/stdb59/sysaux01.dbf',
'/data/u01/app/oracle/oradata/stdb59/undotbs01.dbf',
'/data/u01/app/oracle/oradata/stdb59/users01.dbf',
'/data/u01/app/oracle/oradata/stdb59/liuwenhe.dbf',
'/data/u01/app/oracle/oradata/stdb59/soe.dbf',
'/data/u01/app/oracle/oradata/stdb59/soe3.dbf'
CHARACTER SET AL32UTF8;
Control file created.