how to remove table lock

 
STEP 1:  get  the SID for the table which have lock.
select
   session_id
from
   dba_dml_locks
where
   name = 'table';


output


SID
----
450


STEP 2:  find the Serial# for the table row lock :


select
   sid,
   serial#
from
   v$session
where
   sid in (
   select
      session_id
   from
      dba_dml_locks
   where
      name = 'table');


Output :
SID SERIAL#
---- -------
 450 18341


STEP 3:  Finally "alter system" command to kill the session that is holding the table lock:


alter system kill session 'SID,SERIALl#';
  alter system kill session '450,18341'