alter database add logfile ('D:\OracleFiles\LogFiles\REDO4_A.LOG', 'E:\OracleFiles\LogFiles\REDO4_B.LOG') size 20M;
alter database add logfile group 5 ('D:\OracleFiles\LogFiles\REDO5_A.LOG', 'E:\OracleFiles\LogFiles\REDO5_B.LOG') size 20M;
alter database add logfile member 'E:\OracleFiles\LogFiles\REDO4_C.LOG' to group 4;
alter database add logfile member 'D:\OracleFiles\LogFiles\REDO1_new.LOG' to ('E:\app\Administrator\oradata\orcl\REDO01.LOG') ;
alter database drop logfile member 'E:\OracleFiles\LogFiles\REDO4_C.LOG';
alter database drop logfile group 5;
alter database add logfile ('D:\OracleFiles\LogFiles\REDO4_A.LOG', 'E:\OracleFiles\LogFiles\REDO4_B.LOG', 'F:\OracleFiles\LogFiles\REDO4_C.LOG' ) size 100M;
conn system/1qaz2wsx as sysdba; shutdown immediate; startup mount; alter database archivelog; alter database open;