查找oracle死锁进程sql

SELECT a.username,
       a.machine,
       a.program,
       a.sid,
       a.serial#,
       a.status,
       c.piece,
       c.sql_text
  FROM v$session a,
       v$process b,
       v$sqltext c
WHERE b.spid=<spid> 
   AND b.addr=a.paddr
   AND a.sql_address=c.address(+)
ORDER BY c.piece