ORACLE 12C ORA-00312 redo故障处理

一、描述
DB版本：12.1.0.2
system版本：7.0

二、处理过程
1、报错，数据库启动就实例就会异常终止

ORA-00312: online log 3 thread 1: '+DATADG/ORCLDG/ONLINELOG/group_3.403.962961193'ORA-00312: online log 3 thread 1: '+DATADG/ORCLDG/ONLINELOG/group_3.405.962961193'Mon Jan 08 13:35:53 2018USER (ospid: 15155): terminating the instance due to error 16014Mon Jan 08 13:35:53 2018System state dump requested by (instance=1, osid=15155), summary=[abnormal instance termination].System State dumped to trace file /u01/app/oracle/diag/rdbms/orcldg/orcldg/trace/orcldg_diag_15110_20180108133553.trcMon Jan 08 13:35:53 2018Dumping diagnostic data in directory=[cdmp_20180108133553], requested by (instance=1, osid=15155), summary=[abnormal instance termination].Mon Jan 08 13:35:53 2018Instance terminated by USER, pid = 15155Mon Jan 08 13:39:58 2018Starting ORACLE instance (normal) (OS id: 16121)Mon Jan 08 13:39:58 2018CLI notifier numLatches:3 maxDescs:519Mon Jan 08 13:39:58 2018

2、处理过程

SQL> startup mount;ORACLE instance started.Total System Global Area 1241513984 bytesFixed Size                  2923872 bytesVariable Size             452985504 bytesDatabase Buffers          771751936 bytesRedo Buffers               13852672 bytesDatabase mounted.SQL> SQL> select group#,sequence#,archived,status from v$log;    GROUP#  SEQUENCE# ARC STATUS---------- ---------- --- ----------------         1        356 NO  INACTIVE         3        355 NO  INACTIVE         2        357 NO  CURRENTSQL> alter database clear logfile  group 3 ; alter database clear logfile  group 3*ERROR at line 1:ORA-00350: log 3 of instance orcldg (thread 1) needs to be archivedORA-00312: online log 3 thread 1:'+DATADG/ORCLDG/ONLINELOG/group_3.403.962961193'ORA-00312: online log 3 thread 1:'+DATADG/ORCLDG/ONLINELOG/group_3.405.962961193'SQL> SQL> alter database clear unarchived  logfile  group 3 ;Database altered.SQL> alter database open;Database altered.

3、说明
我这里是一个ADG，主库这样操作会导致GAP，备库需要增量恢复。