oracle 10g 逻辑standby 切换步骤

(1)switchover：

 

主库：alter database prepare to switchover to logical standby;

 

备库：alter database prepare to switchover to primary;

 

--此时，备库应该将日志应用完毕

alter database start logical standby apply:

 

主库：alter database commit to switchover to logical standby;

 

备库：alter database commit to switchover to primary;

 

上原来的主库查询：

select database_role from v$database;

DATABASE_ROLE
----------------
LOGICAL STANDBY

 

然后上备库查：

 select database_role from v$database;

DATABASE_ROLE
----------------
PRIMARY

(2)failover:

如果主库发生故障，要将备库作为主库，运行：
alter database activate logical standby database;

 

startup force;

 

备库起来以后，变成了主库。