Step 1 Verify that the primary database can be switched to the standby role.
验证主库能够切换到备用角色。
SELECT SWITCHOVER_STATUS FROM V$DATABASE;
idle>:wq
SWITCHOVER_STATUS
--------------------
TO STANDBY
Step 2 Initiate the switchover on the primary database.
在主库上面开始切换
alter database commit to switchover to physical standby with session shutdown ;
Step 3 Shut down and then mount the former primary database.
关闭并且mount上从前的主库。
shutdown abort;
startup mount ;
Step 4 Verify that the switchover target is ready to be switched to the primary role.
验证转换目标已经准备好转换为主库角色
SWITCHOVER_STATUS
--------------------
SWITCHOVER LATENT
这里查询出来的值不为TO_PRIMARY即有点问题。
执行下一步的时候可能会出现问题。
Step 5 Switch the target physical standby database role to the primary role.
转换目标逻辑备用库角色为主库角色。
sys@DEX> ALTER DATABASE COMMIT TO SWITCHOVER TO PRIMARY WITH SESSION SHUTDOWN;
ALTER DATABASE COMMIT TO SWITCHOVER TO PRIMARY WITH SESSION SHUTDOWN
*
ERROR at line 1:
ORA-16139: media recovery required
这里提示需要介质恢复。
sys@DEX> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE DISCONNECT FROM SESSION;
Database altered.
sys@DEX> SELECT SWITCHOVER_STATUS FROM V$DATABASE;
SWITCHOVER_STATUS
--------------------
TO PRIMARY
sys@DEX> ALTER DATABASE COMMIT TO SWITCHOVER TO PRIMARY WITH SESSION SHUTDOWN;
Database altered.
Step 6 Open the new primary database.
打开新的主库
sys@DEX> ALTER DATABASE OPEN;
Database altered.
Step 7Verify the switch role .
验证角色转换
主库执行
sys@DEX> alter system switch logfile ;
System altered.
sys@DEX> select sequence# from v$log ;
SEQUENCE#
----------
40
41
42
sys@DEX>
standby库执行
sys@DEX> select sequence# from v$log ;
SEQUENCE#
----------
40
42
41
sys@DEX>
