I'm getting the following ora error message:

SQL> alter database drop logfile group 9;
alter database drop logfile group 9
*
ERROR at line 1:
ORA-01624: log 9 needed for crash recovery of instance proddb (thread 1)
ORA-00312: online log 9 thread 1: '+SHARED_DATA_DG03/proddb/onlinelog/group_9.273.685470789'

At first I couldn't figure out why it was giving me this message even thought I switched my logs several times.  My database is open and the current active log was group 2 and when i tried to drop group 9 this is the error that I got.  Then after looking at oerr ora 01624 it immediately occurred to me to do a checkpoint so this is what i did:

SQL> alter system checkpoint;

System altered.

After I issued this statement, it allowed me to drop the group:

SQL> alter database drop logfile group 9;

Database altered.

Hope this helps.

Thanks,