如果仅仅是lock，以下语句可以发现所有用户锁 :
SELECT s.username,
decode(l.type, 'TM', 'TABLE LOCK', 'TX', 'ROW LOCK', NULL) LOCK_LEVEL,
o.owner,
o.object_name,
o.object_type,
s.sid,
s.serial#,
s.terminal,
s.machine,
s.program,
s.osuser
from v$session s, v$lock l, all_objects o
WHERE l.sid = s.sid
AND l.id1 = o.object_id(+)
AND s.username is NOT Null
如果有锁等待或死锁，可以通过以下语句发现:
select lpad(' ', decode(l.xidusn, 0, 3, 0)) || l.oracle_username User_name,
o.owner,
o.object_name,
o.object_type
from v$locked_object l, dba_objects o
where l.object_id = o.object_id
order by o.object_id desc
About parent vs child latches. There is no fundamental low level difference between parent and child latches, they are all small regions of memory modified with atomic test-and-set style opcodes.
You see parent (and solitary) latches from x$ksll ......
