oracle DG主备切换

朱雀 2022-06-17 01:06 258阅读 0赞

\---------正常切换  
\--切换前确认下主备信息  
select open\_mode, switchover\_status, database\_role, db\_unique\_name from v$database;  
  
  
\--主库  
alter database commit to switchover to physical standby with session shutdown;  
shutdown immediate;  
startup;  
alter database recover managed standby database using current logfile disconnect from session;  
  
  
\--备库  
alter database commit to switchover to primary with session shutdown;  
alter database open;  
  
  
\--切换后跟踪下日志应用（需要等片刻）  
select max(sequence\#) from v$archived\_log;  
  
  
  
  
\---------强制切换  
\--没有应用的日志，复制scp到备库并注册  
select thread\#, low\_sequence\#, high\_sequence\# from v$archive\_gap;  
alter database register physical logfile 'filename';  
  
  
alter database recover managed standby database finish force;  
alter database commit to switchover to primary with session shutdown;  
alter database open;  
  
  
  
  
\--之前的主库重回DG环境  FLASHBACK方式  
select to\_char(standby\_became\_primary\_scn) from v$database;  
select to\_char(scn\_to\_timestamp(3055000),'yyyy-mm-dd hh24:mi:ss') from dual;  
  
  
shutdown immediate;   
startup mount;   
flashback database to scn 3056007;   
  
  
  
  
\--使用FLASHBACK database需要开启数据库级别的闪回。默认是off。（可使用rman恢复到某个时间点）  
run\{  
set until time "to\_date('2016-02-16 16:13:29','yyyy-mm-dd hh24:mi:ss')";  
restore database;  
recover database;  
\}  
  
  
restore database until scn 3056007  
  
  
\--恢复后 转换为备库并同步日志  
alter database convert to physical standby;   
shutdown immediate;   
startup;   
alter database recover managed standby database using current logfile disconnect from session;