MySQL千万大表优化方案

[AlfieriChou]

参考文章：https://cloud.tencent.com/developer/beta/article/1705504

[AlfieriChou]

subquery查询可以优化成临时表关联

1. 案例样本

   select 
   * 
   from 
   a_table 
   where 
   b in (
   select 
     b 
   from 
     d_table 
   where 
     k = '11111' 
   group by 
     b
   )

2.优化后方案

select 
  * 
from 
  a_table 
  left join (
    select 
      b 
    from 
      d_table 
    where 
      k = '11111' 
    group by 
      b
  ) as t_table on t_table.b = a_table.b