执行该mysql语句很慢

Question

explain SELECT btitle.id,btitle.hit,btitle.bbstop,btitle.sign,btitle.huati,btitle.P_display,btitle.bbs_img,btitle.title,btitle.redate,btitle.rep,btitle.picture,btitle.name FROM bbstitle btitle WHERE btitle.BoardID_1='A_6' AND btitle.BoardID_2='A_6_4' AND btitle.deleted=0 ORDER BY bbstop desc,SIGN DESC,huati desc,redate desc LIMIT 0,30+----+-------------+--------+------+-----------------------------+-----------+---------+-------+------+-----------------------------+
| id | select_type | table  | type | possible_keys               | key       | key_len | ref   | rows | Extra                       |
+----+-------------+--------+------+-----------------------------+-----------+---------+-------+------+-----------------------------+
|  1 | SIMPLE      | btitle | ref  | deleted,BoardID_2,BoardID_1 | BoardID_2 | 1002    | const | 1001 | Using where; Using filesort | 
+----+-------------+--------+------+-----------------------------+-----------+---------+-------+------+-----------------------------+

Answer 1

BoardID_1，btitle.BoardID_2，deleted
这三个字段加联合索引

Answer 2

谢谢，你说对了一半，不仅仅是where这块需要建立，而且在order by这块也需要建立。性能上才提升很多。之前是5秒多，现在建立之后，是保证在500毫秒之下。