standby库从readonly状态转到recover状态

standby库从readonly状态转到recover状态，本来用以下命令直接可以切换

alter database recover managed standby database disconnect from session;

 

但如果切换时，仍有用户连接，以上命令切换会失败。

 

方法一：shutdown immediate standby库，然后再启动到recover模式

方法二：把已连接的用户kill掉，再执行切换

   Terminate any active user sessions on the standby database (except your own):
      select 'alter system kill session ''' || sid || ',' || serial# || ''';'
         from v$session where username is not null
         and sid not in (select distinct sid from v$mystat);
      select '!kill -9 ' || vp.spid
         from v$session vs,v$process vp where vs.paddr = vp.addr
         and vs.username is not null
         and vs.sid not in (select distinct sid from v$mystat);
   alter database recover managed standby database disconnect from session;