DG切换角色时发生ORA-16416: 切换目标与主目标不同步解决方法

主库上操作：

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

DATABASE_ROLE    OPEN_MODE PROTECTION_MODE      PROTECTION_LEVEL     SWITCHOVER_STATUS
---------------- ---------- -------------------- -------------------- --------------------
PRIMARY          READ WRITE MAXIMUM PERFORMANCE MAXIMUM PERFORMANCE SESSIONS ACTIVE

--尝试切换：

SQL> alter database commit to switchover to physical standby with session shutdown;
alter database commit to switchover to physical standby with session shutdown
*
第 1 行出现错误:
ORA-16416: 切换目标与主目标不同步

SQL> !oerr ora 16416
16416, 00000, "Switchover target is not synchronized with the primary"
// *Cause: The switchover target incurred an error or has a gap at the time
//          the switchover operation was attempted.
// *Action: Allow the switchover target to become synchronized and then
//          re-attempt the switchover.

 

解决方法：
1、startup mount主库，创建备库控制文件，拷贝到备库机器；

SQL> alter database create standby controlfile as '/backup/sdtby_control01.ctl';

数据库已更改。

SQL> alter database open;

数据库已更改。
2、shutdown备库，替换控制文件，startup mount；

SQL> select switchover_status,database_role from v$database;

SWITCHOVER_STATUS    DATABASE_ROLE
-------------------- ----------------
RECOVERY NEEDED      PHYSICAL STANDBY

SQL> alter database recover managed standby database disconnect from session;

数据库已更改。

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

DATABASE_ROLE    OPEN_MODE PROTECTION_MODE      PROTECTION_LEVEL     SWITCHOVER_STATUS
---------------- ---------- -------------------- -------------------- --------------------
PHYSICAL STANDBY MOUNTED    MAXIMUM PERFORMANCE MAXIMUM PERFORMANCE TO PRIMARY

SQL> select max(SEQUENCE#) from v$archived_log;

MAX(SEQUENCE#)
--------------
            49

最后验证一下主备库角色是否正确：
SQL> select switchover_status,database_role from v$database;

SWITCHOVER_STATUS    DATABASE_ROLE
-------------------- ----------------
SESSIONS ACTIVE      PRIMARY

SQL> select switchover_status,database_role from v$database;

SWITCHOVER_STATUS    DATABASE_ROLE
-------------------- ----------------
TO PRIMARY           PHYSICAL STANDBY