select oracle_username
,      object_name
,      decode(a.locked_mode,
              0, 'None',           /* Mon Lock equivalent */
              1, 'Null',           /* N */
              2, 'Row-S (SS)',     /* L */
              3, 'Row-X (SX)',     /* R */
              4, 'Share',          /* S */
              5, 'S/Row-X (SSX)',  /* C */
              6, 'Exclusive',      /* X */
       to_char(a.locked_mode)) mode_held
   from v$locked_object a
   ,    dba_objects b 
  where a.object_id = b.object_id
/