利用 force index优化sql语句性能

    今天写了一个统计sql，在一个近亿条数据的表上履行，200s都查不出成果。SQL以下：

select customer,count(1) c
from upv_**
where created between "2015-07-06" and "2015-07-07"
group by customer 
having c > 20
order by c desc
s