如何加速MySQL查询（计数不同和加入）

Question

您有什么想法，我如何加快后续查询？

 [
        'format'=>'raw',
       'attribute' =>'patron_firstName',
         'value' => function($model,$key,$index)
         {

             $firstName=$name->patron_firstName;
             $lastName=$name->patron_lastName;
             $fullName=$firstName." ".$lastName;
             return $fullName;
        }


        ],

我试过这种方式：

select count(distinct t1.var1)
from table_a t1
join table_b t2 on t1.var2 = t2.var1
   and t2.date between '2016-11-05 00:00:00' and '2016-11-10 23:59:59'
   and t2.var3 = 3;

但它并不比前一个快

Answer 1

select count(distinct(t1.var1))
from table_a t1
join (select * from table_b where date between ('2016-11-05 00:00:00') and ('2016-11-10 23:59:59') and var3 = 3) t2 
on t1.var2 = t2.var1;

在执行连接之前应用fiters