MySql语句SUM、MAX优化：数据库版本5.7.26

Question

MySql语句SUM、MAX优化：数据库版本5.7.26

为了避免大家误会，我用*直接代替了，也就是三个表查询出来的内容都是不能省略的。

 SELECT *  FROM khxx a 
  inner JOIN 
        (SELECT YXTKHH,HXJGBM,sum(jjye) AS jjye FROM dkxx GROUP BY YXTKHH,HXJGBM) c ON a.HXJGBM=c.HXJGBM AND a.YXTKHH=c.YXTKHH 
  left JOIN 
        (SELECT JKRXZ,update_time,SFNCZ, YXTKHH,HXJGBM FROM gqc WHERE id IN (SELECT max(id) FROM gqc GROUP BY YXTKHH,HXJGBM)) b ON a.YXTKHH=b.YXTKHH AND a.HXJGBM=b.HXJGBM 

用到了 all 和 Using temporary; Using filesort，如何优化？

Answer 1

把a表放到后面？