Run this query when the "hang" is happening SELECT DECODE(request,0,'Holder: ','Waiter: ')||sid sess,=20 id1, id2, lmode, request, type FROM V$LOCK WHERE (id1, id2, type) IN (SELECT id1, id2, type FROM V$LOCK WHERE request>0) ORDER BY id1, request / -- //www.freelists.org/webpage/oracle-l