DataGuard 日常维护



1.停止Standby

select process, status from v$managed_standby; --查看备库是否在应用日志进行恢复

alter database recover managed standby database cancel;
shutdown immediate;

 

2.切换到只读模式

-----由shutdown模式切换到只读模式-------

startup nomount;
alter database mount standby database;
alter database open read only;

-----由应用日志模式切换到只读模式-------

alter database recover managed standby database cancel;-- 取消日志应用
alter database open read only;

 

3.切换回管理恢复模式

startup nomount;
alter database mount standby database;
alter database recover managed standby database disconnect from session;-- 启动日志应用

alter database recover managed standby database using current logfile disconnect from session;

 

4.主库和备库之间角色切换

4.1 主库切换为备库
alter database commit to switchover to physical standby;

alter database commit to switchover to physical standby with session shutdown;-- 主库有会话连接的时候
shutdown immediate
startup nomount;
alter database mount standby database;
alter database recover managed standby database disconnect from session;

 

4.2 从库切换为主库

alter database commit to switchover to primary;
shutdown immediate;
startup
alter system switch logfile;

 

5.备库自动使用主库传过来的日志进行恢复

alter database recover automatic standby database;

 

6.更改保护模式

alter database set standby database to maximize protection;
alter database set standby database to maximize availability;
alter database set standby database to maximize performancen;

 

7.取消自动恢复模式

alter database recover managed standby database cancel;
alter database recover managed standby database finish;
alter database recover managed standby database finish force;