在物理DG主备库切换时遇到ORA-16139: media recovery required错误

SQL> ALTER DATABASE COMMIT TO SWITCHOVER TO PRIMARY;
ALTER DATABASE COMMIT TO SWITCHOVER TO PRIMARY
*
ERROR at line 1:
ORA-16139: media recovery required

解决办法：

 --如果报ORA-16139: media recovery required，可能是由于未应用日志引起，可先执行

ALTER  DATABASE RECOVER MANAGED STANDBY  DATABASE DISCONNECT FROM SESSION;

然后再执行该命令