SELECT s.username, l.type, o.object_name,
DECODE(l.lmode, 2, 'Row-S(SS)',
3,'Row-X(SX)',
4, 'Share',
5, 'S/Row-X(SSX)',
6, 'Exclusive', 'Other' Mode_Held,
FROM dba_objects o, v$session s, v$lock l
WHERE s.sid = l.sid
AND o.object_id = l.id1
AND s.username is not null;