set serveroutput on
BEGIN
   dbms_output.enable(1000000);
  for do_loop in (select session_id, a.object_id, xidsqn, oracle_username, b.owner owner,
   b.object_name object_name, b.object_type object_type
  FROM v$locked_object a, dba_objects b
    WHERE xidsqn != 0
    and b.object_id = a.object_id)
   loop
   dbms_output.put_line('.');
  dbms_output.put_line('Blocking Session : '||do_loop.session_id);
  dbms_output.put_line('Object (Owner/Name): '||do_loop.owner||'.'||do_loop.object_name);
  dbms_output.put_line('Object Type : '||do_loop.object_type);
  for next_loop in (select sid from v$lock
   where id2 = do_loop.xidsqn
   and sid != do_loop.session_id)
   LOOP
   dbms_output.put_line('Sessions being blocked : '||next_loop.sid);
   end loop;
   end loop;
   END;
   /