1、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;

2、切换当前日志到新的日志组

alter system switch logfile;

alter system switch logfile;

3、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;

4、操作系统下删除原日志组1、2、3中的文件

5、重建日志组1、2、3

alter database add logfile group 1 ('D:\ORACLE\ORADATA\ORADB\REDO01_1.LOG') size 10M;

alter database add logfile group 2 ('D:\ORACLE\ORADATA\ORADB\REDO02_1.LOG') size 10M;

alter database add logfile group 3 ('D:\ORACLE\ORADATA\ORADB\REDO03_1.LOG') size 10M;

6、切换日志组

alter system switch logfile;

alter system switch logfile;

alter system switch logfile;

7、删除中间过渡用的日志组4、5

alter database drop logfile group 4;

alter database drop logfile group 5;

8、到操作系统下删除原日志组4、5中的文件

9、备份当前的最新的控制文件

SQL> connect / as sysdba

SQL> alter database backup controlfile to trace resetlogs