ORA-16629: database reports a different protection

Oracle 12c RAC-单实例 告警如下：

DGMGRL> show database verbose coredb;

Database - coredb

  Role:               PRIMARY
  Intended State:     TRANSPORT-ON
  Instance(s):
    coredb1
    coredb2

  Database Warning(s):
    ORA-16629: database reports a different protection level from the protection mode
	.....省略......

保护模式是我们设置的，保护级别是当前状态的。

SQL> select database_role,protection_mode,protection_level from v$database;

DATABASE_ROLE    PROTECTION_MODE      PROTECTION_LEVEL
---------------- -------------------- --------------------
PHYSICAL STANDBY MAXIMUM AVAILABILITY **RESYNCHRONIZATION**

因为测试的原因，把日志传输进程defer掉了，重新enable之后需要追赶几百个归档文件，最高可用降级到最大性能模式，变成了异步。自己在测试环境做了测试， 发现追平之后就不会有告警了！！以上只做一个记录。

追平后：

SQL> select database_role,protection_mode,protection_level from v$database;

DATABASE_ROLE    PROTECTION_MODE      PROTECTION_LEVEL
---------------- -------------------- --------------------
PHYSICAL STANDBY MAXIMUM AVAILABILITY MAXIMUM AVAILABILITY

DGMGRL> show configuration;

Configuration - dg_config

  Protection Mode: MaxAvailability
  Members:
  orcl   - Primary database
    orcldg - Physical standby database 

Fast-Start Failover: DISABLED

Configuration Status:
SUCCESS   (status updated 13 seconds ago)

你什么都不需要做，坐等一切都恢复正常就好了！！我们只需要知道原因就好！！