--创建2个新的日志组
alter database add logfile group 4 ('D:\ORACLE\ORADATA\ORADB\REDO04_1.LOG') size 1024k;
alter database add logfile group 5 ('D:\ORACLE\ORADATA\ORADB\REDO05_1.LOG') size 1024k;
--切换当前日志到新的日志组，目的使得修改的日志组非Active 状态
alter system switch logfile;
alter system switch logfile;
--删除旧的日志组
alter database drop logfile group 1;
alter database drop logfile group 2;
alter database drop logfile group 3;
--操作系统下删除原日志组1、2、3中的文件
--重建日志组1、2、3
alter database add logfile group 1 ('/home/oracle/ORADATA/redotest/REDO01_1.LOG') size 500M;
alter database add logfile group 2 ('/home/oracle/ORADATA/redotest/REDO02_1.LOG') size 500M;
alter database add logfile group 3 ('/home/oracle/ORADATA/redotest/REDO03_1.LOG') size 500M;