DG相关操作

1.开启apply进程 #前台应用redo日志，会话不会退出

alter database recover managed standby database;

#后台应用redo日志

alter database recover managed standby database disconnect from session;

2.取消apply进程

alter database recover managed standby database cancel；

3.延迟应用redo日志

alter database recover managed standby database cancel;
alter database recover managed standby database delay 30 disconnect from session;
​
alter database recover managed standby database cancel;
alter database recover managed standby database nodelay disconnect from session;

4.开启实时应用redo日志

alter database recover managed standby database using current logfile;

5.检查日志应用进度

alter session set nls_date_format='dd-mon-yyyy hh24:mi:ss';
​
select sequence#, first_time, next_time, applied
from   v$archived_log
order by sequence#;

6.dg的模式切换

-- maximum availability.
alter system set log_archive_dest_2='service=db11g_stby affirm sync valid_for=(online_logfiles,primary_role) db_unique_name=db11g_stby';
alter database set standby database to maximize availability;
​
-- maximum performance.
alter system set log_archive_dest_2='service=db11g_stby noaffirm async valid_for=(online_logfiles,primary_role) db_unique_name=db11g_stby';
alter database set standby database to maximize performance;
​
-- maximum protection.
alter system set log_archive_dest_2='service=db11g_stby affirm sync valid_for=(online_logfiles,primary_role) db_unique_name=db11g_stby';
shutdown immediate;
startup mount;
alter database set standby database to maximize protection;
alter database open;

7.switchover的过程 在primary端： #将primary转换成standby

connect /as sysdba
alter database commit to switchover to standby;

#关闭primary

shutdown immediate

#将老的primary以standby的角色mount起来

startup nomount；
alter database mount standby database;
alter database recover managed standby database disconnect from session;

在standby端： #将standby转换成primary

connect /as sysdba
alter database commit to switchover to primary;

#关闭standby

shutdown immediate;

#开启老的stanby成为primary

startup;

8.failover的过程

alter database recover managed standby database finish;
alter database activate standby database;

9.将standby置为只读的

shutdown immediate;
startup mount;
alter database open read only;

10.将standby置为recover模式

shutdown immediate;
startup mount;
alter database recover managed standby database disconnect from session;

11.开启ADG(11g)

shutdown immediate;
startup mount;
alter database open read only;
alter database recover managed standby database disconnect from session;

12.快照standby #如果是rac，留下一个实例，其它全部关闭

shutdown immediate;
startup mount;

#关闭recovery

alter database recover managed standby database cancel;

#切换成快照standby

select flashback_on from v$database;
​
flashback_on
------------------
​
no
​
alter database convert to snapshot standby;
alter database open;
select flashback_on from v$database;
​
flashback_on
------------------
​
restore point only
​
sql>

现在就是读写模式了

#切换成standby模式

shutdown immediate;
startup mount;
alter database convert to physical standby;
shutdown immediate;
startup nomount;
alter database mount standby database;
alter database recover managed standby database disconnect;
select flashback_on from v$database;
​
flashback_on
------------------
​
no
​
sql>