SELECT * FROM v$lock ORDER BY ctime DESC;

SELECT 
  l1.sid AS "阻塞會話ID",
  s1.username AS "阻塞用戶",
  s1.osuser AS "阻塞OS用戶",
  s1.machine AS "阻塞機器",
  l2.sid AS "被阻塞會話ID",
  s2.username AS "被阻塞用戶",
  l1.type AS "鎖類型",
  DECODE(l1.type,
    'TX', '事務鎖',
    'TM', '表鎖',
    'UL', '用戶鎖',
    l1.type) AS "鎖描述",
  l1.ctime AS "持有時間(秒)"
FROM v$lock l1, v$lock l2, v$session s1, v$session s2
WHERE l1.block = 1 
AND l2.request > 0
AND l1.id1 = l2.id1
AND l1.id2 = l2.id2
AND l1.sid = s1.sid
AND l2.sid = s2.sid;

SELECT l.sid, s.username, s.status, l.type, l.lmode, l.ctime, o.object_name
FROM v$lock l, dba_objects o, v$session s
WHERE l.id1 = o.object_id(+)
AND l.type = 'TM'
AND l.sid = s.sid
AND o.object_name = 'EMPLOYEES';

-- 1. 查找阻塞會話
SELECT sid, serial#, username FROM v$session 
WHERE sid IN (SELECT blocking_session FROM v$session WHERE blocking_session IS NOT NULL);

-- 2. 終止會話
ALTER SYSTEM KILL SESSION 'sid,serial#' IMMEDIATE;