ERROR ORA-00312 ,ORA-00350 LOGFILE DELETED .....

SQL>
SQL> select open_mode from v$database;

OPEN_MODE
----------
MOUNTED

SQL>
SQL>
SQL> alter database drop logfile group 1;
alter database drop logfile group 1
*
ERROR at line 1:
ORA-00350: log 1 of instance orcl (thread 1) needs to be archived
ORA-00312: online log 1 thread 1:
'/oracle/product/10.2.0/oradata/orcl/redo01.log'


SQL>
SQL>
SQL> select  member from v$logfile;

MEMBER
--------------------------------------------------------------------------------
/oracle/product/10.2.0/oradata/orcl/redo03.log
/oracle/product/10.2.0/oradata/orcl/redo02.log
/oracle/product/10.2.0/oradata/orcl/redo01.log

SQL> ELECT STATUS FROM V$LOG WHERE GROUP#=1;
SP2-0734: unknown command beginning "ELECT STAT..." - rest of line ignored.
SQL> sELECT STATUS FROM V$LOG WHERE GROUP#=1;

STATUS
----------------
INACTIVE

SQL>
SQL> ALTER DATABASE DROP LOGFILE GROUP 1;
ALTER DATABASE DROP LOGFILE GROUP 1
*
ERROR at line 1:
ORA-00350: log 1 of instance orcl (thread 1) needs to be archived
ORA-00312: online log 1 thread 1:
'/oracle/product/10.2.0/oradata/orcl/redo01.log'


SQL> ALTER DATABASE DROP LOGFILE GROUP1
  2  ;
ALTER DATABASE DROP LOGFILE GROUP1
                            *
ERROR at line 1:
ORA-02236: invalid file name


SQL>
SQL> ALTER DATABASE DROP LOGFILE GROUP 1;
ALTER DATABASE DROP LOGFILE GROUP 1
*
ERROR at line 1:
ORA-00350: log 1 of instance orcl (thread 1) needs to be archived
ORA-00312: online log 1 thread 1:
'/oracle/product/10.2.0/oradata/orcl/redo01.log'


SQL> alter database clear unarchived logfile group 1;

Database altered.

SQL> alter database drop logfile group 1;

Database altered.

SQL>
SQL> alter database add logfile group 1 '/oracle/product/10.2.0/oradata/orcl/redo01.log' size 10m;
alter database add logfile group 1 '/oracle/product/10.2.0/oradata/orcl/redo01.log' size 10m
*
ERROR at line 1:
ORA-00301: error in adding log file
'/oracle/product/10.2.0/oradata/orcl/redo01.log' - file cannot be created
ORA-27038: created file already exists
Additional information: 1


SQL> alter database add logfile group 1 '/oracle/product/10.2.0/oradata/orcl/redo01.log' reuse;

Database altered.

SQL>