发现生产环境的Oracle数据库cpu使用率上升超过70%,其中一条查询语句达到每秒调用40多次.现在我们来观摩下该语句: select t.id,t.level,t.policy, t.type,t1.point,t2.channel,t3.user from t_wlf_charge t, t_wlf_point t1, t_wlf_channel t2, (select t4.id,t4.phone user from t_wlf_user t4 where t4.phone=? ) t3