Kill inactive sessions

If you want to kill all inactive session in database which has been wait 10 minutes.
You can use below statements.

SQL> select count(*) from v$session;

  COUNT(*)
----------
      503

SQL> select 'alter system kill session '''||sid||','||serial#||''' immediate;' cmd
from v$session where last_call_et>600 and status='INACTIVE';

CMD
----------------------------------------------------------------------
alter system kill session '3803,3' immediate;
alter system kill session '3806,5' immediate;
alter system kill session '3811,3' immediate;
alter system kill session '3813,10' immediate;
alter system kill session '3814,20' immediate;
alter system kill session '3816,14' immediate;
alter system kill session '3823,135' immediate;
alter system kill session '3824,25' immediate;
.....