ORA-01567: dropping log 1 would leave less than 2 log files

#Error while dropping less than two redo log groups. SQL> alter database drop logfile group 1; alter database drop logfile group 1 * ERROR at line 1: ORA-01567: dropping log 1 would leave less than 2 log files for instance test (thread 1) ORA-00312: online log 1 thread 1: 'D:\RUPESH\SETUPS\TEST\TEST\ONLINELOG\REDO01.LOG' Cause:  You can not drop all the groups and keep only one group. Minimum two redo log groups are required for the instance.  Solution: Add more redo log groups and drop the existing ones if you want to drop it. #First check the status of the redo log group members. SQL> set lines 300 pages 3000 SQL> col member for a70 SQL> select group#,type,member from v$logfile order by 1; GROUP# TYPE    MEMBER ------ ------- -----------------------------------------------      1 ONLINE  D:\RUPESH\SETUPS\TEST\TEST\ONLINELOG\REDO01.LOG      2 ONLINE  D:\RUPESH\SETUPS\TEST\TEST\ONLINELOG\REDO02.LOG   SQL> select group#,thread#,sequence#,members,archived,status from v$log order by 1; GROUP# THREAD#  SEQUENCE#    MEMBERS ARC STATUS ------ ------- ---------- ---------- --- --------      1       1        121          1 YES INACTIVE      2       1        122          1 NO  CURRENT #Add more redo log groups to drop existing ones. SQL> alter database add logfile group 3 'D:\RUPESH\SETUPS\TEST\TEST\ONLINELOG\REDO3.log' size 200m; Database altered. SQL> select group#,type,member from v$logfile order by 1; GROUP# TYPE    MEMBER ------ ------- -----------------------------------------------      1 ONLINE  D:\RUPESH\SETUPS\TEST\TEST\ONLINELOG\REDO1.LOG      2 ONLINE  D:\RUPESH\SETUPS\TEST\TEST\ONLINELOG\REDO2.LOG      3 ONLINE  D:\RUPESH\SETUPS\TEST\TEST\ONLINELOG\REDO3.LOG SQL> alter system switch logfile; System altered. SQL> alter system switch logfile; System altered. SQL> alter system checkpoint; System altered. SQL> select group#,thread#,sequence#,members,archived,status from v$log order by 1; GROUP#    THREAD#  SEQUENCE#    MEMBERS ARC STATUS ------ ---------- ---------- ---------- --- ---------      1          1        124          1 YES INACTIVE      2          1        125          1 YES INACTIVE      3          1        126          1 NO  CURRENT SQL> alter database drop logfile group 1; Database altered. SQL> select group#,thread#,sequence#,members,archived,status from v$log order by 1; GROUP#    THREAD#  SEQUENCE#    MEMBERS ARC STATUS ------ ---------- ---------- ---------- --- --------      2          1        125          1 YES INACTIVE      3          1        126          1 NO  CURRENT