Modify the size of an Oracle Log File

1. create two new log groups
Alter database add logfile Group 4 ('d: \ oracle \ oradata \ oradb \ redo04_1.log ') size 1024 K;
Alter database add logfile group 5 ('d: \ oracle \ oradata \ oradb \ redo05_1.log ') size 1024 K;
　　
2. Switch the current log to a new log group.
Alter system switch logfile;
Alter system switch logfile;
　　
3. Delete the old log Group
Alter database drop logfile group 1;
Alter database drop logfile group 2;
Alter database drop logfile group 3;
　　
4. delete files in the original log group 1, 2, and 3 in the operating system
　　
5. Rebuild log groups 1, 2, and 3
Alter database add logfile group 1 ('d: \ oracle \ oradata \ oradb \ redo01_1.log ') Size 10 m;
Alter database add logfile group 2 ('d: \ oracle \ oradata \ oradb \ redo02_1.log ') Size 10 m;
Alter database add logfile group 3 ('d: \ oracle \ oradata \ oradb \ redo03_1.log ') Size 10 m;
　　
6. Switch the log Group
Alter system switch logfile;
Alter system switch logfile;
Alter system switch logfile;
　　
7. Delete the log groups for intermediate transition. 4 and 5
Alter database drop logfile group 4;
Alter database drop logfile group 5;
　　
8. delete files in log group 4 and 5 under the Operating System
　　
9. Back up the latest Control File
SQL> connect/As sysdba

SQL> alter Database Backup controlfile to trace resetlogs