报错：
resource busy and acquire with NOWAIT specified or timeout expired
解决：
BEGIN
FOR C IN (SELECT S.SID SID, S.SERIAL# SERIAL FROM V$LOCKED_OBJECT L, V$SESSION S WHERE L.SESSION_ID = S.SID) LOOP
EXECUTE IMMEDIATE ('ALTER SYSTEM KILL SESSION ''' || C.SID || ',' || C.SERIAL || '''');
END LOOP;
END;
