学步园

    
    假如原来有3个小的redo log file, 下面是UNIX环境下的一个例子:
   
    第一步: 往数据库添加三个大的redo logfile
   
    SVRMGRL>ALTER DATABASE ADD LOGFILE GROUP 4
('/opt/oradata/app/redo04.log',
'/ora_bak/oradata2/redolog/redo04.log') size 16M reuse;

    SVRMGRL>ALTER DATABASE ADD LOGFILE GROUP 5
('/opt/oradata/app/redo05.log',
'/ora_bak/oradata2/redolog/redo05.log') size 16M reuse;

    SVRMGRL>ALTER DATABASE ADD LOGFILE GROUP 6
('/opt/oradata/app/redo06.log',
'/ora_bak/oradata2/redolog/redo06.log') size 16M reuse;

    第二步: 手工地做log switch, 使新建的redo logfile起作用.
   
    SVRMGRL>alter system switch logfile;

    此操作可以执行一到几次, 使旧的redo logfile成inactive状态.

    第三步: 删除原来旧的redo logfile.
   
    SVRMGRL>alter database drop logfile group 1;

    SVRMGRL>alter database drop logfile group 2;

    SVRMGRL>alter database drop logfile group 3;