1. Redolog file是CURRENT的时候被删除, 清除日志时报错：ORA-01624：
    SQL> startup mount
ORA-32004: obsolete or deprecated parameter(s) specified for RDBMS instance
ORACLE instance started.


Total System Global Area  354914304 bytes
Fixed Size                  2253224 bytes
Variable Size             180358744 bytes
Database Buffers          167772160 bytes
Redo Buffers                4530176 bytes
Database mounted.
SQL> alter system set "_allow_resetlogs_corruption" = true scope=spfile;


System altered.


SQL> recover database until cancel; 
Media recovery complete.
SQL> alter database open resetlogs;


Database altered.


SQL> alter system reset  "_allow_resetlogs_corruption"  scope=spfile sid='*' 
  2  /


System altered.


2. LOGFILE非CURRENT也非ACTIVE
SQL> startup mount
ORA-32004: obsolete or deprecated parameter(s) specified for RDBMS instance
ORACLE instance started.


Total System Global Area  354914304 bytes
Fixed Size                  2253224 bytes
Variable Size             180358744 bytes
Database Buffers          167772160 bytes
Redo Buffers                4530176 bytes
Database mounted.
SQL> alter database clear logfile group 2;


Database altered.


SQL> alter database open;


Database altered.
参考：http://oracle.so138.com/ora/ora-01624log-1-needed-crash-recovery-instance-oracle-jia-yuan
        http://www.orasos.com/tag/ora-01624