See who the table is lock and unlock

--Query for locked tables and related session information
SELECT object_name,
       session_id SID,
        MACHINE,
       VS. MODULE,
       ' alter   system   kill   session    ' | | session_id | | ',' ||
       serial# | | ''';' Kill_session,
       VS. STATUS,
       VS. ACTION,
       serial#,
       oracle_username ,
       os_user_name
  from V$locked_object VO, V$session VS, All_objects AO
 where VO. session_id = VS. SID
   and AO. object_id = VO. OBJECT_ID
   and NVL (VS. ACTION, '    ') <> ' service   Management '
 order by object_name, MACHINE, VS. MODULE;

Unlock the SQL of the Kill

Alter system kill session ' SID, Serial# '