gistfile1.sql

SELECT
    l1.type,
    s1.sid blocker_sid, s1.machine blocker_machine, s1.sql_id blocker_sql_id,
    s2.sid blocked_sid, s2.machine blocked_machine, s2.sql_id blocked_sql_id,
    obj.object_type, obj.object_name
FROM v$lock l1 JOIN v$lock l2 ON (l1.id1 = l2.id1 AND l1.id2 = l2.id2)
JOIN v$session s1 ON (s1.sid = l1.sid) JOIN v$session s2 on (s2.sid = l2.sid)
LEFT JOIN dba_objects obj ON (obj.object_id = l1.id1)
WHERE l1.lmode > 1 AND l2.request > 1;