jquery - SQL 不在长时间响应中

Question

我遇到了一个 SQL 查询问题，该查询返回了我想要的值，但在很长一段时间之后。

我可以在代码中更改哪些内容以进行时序优化？:

select * 
from t1 
where 
(t1.date between '01/01/2016' and '05/01/2016') 
and (t1.section = 'KA') 
and t1.protocol not in (select t2.protocol from t2 where (date between '01/01/2016' and '05/01/2016') and (section = 'KA'))

Answer 1

尝试使用不存在:

select t1.* 
from t1 
where t1.date between '2016-01-01' and '2016-05-01' and
      t1.section = 'KA' and
      not exists (select 1
                  from t2
                  where t2.protocol = t1.protocol and
                        t2.date between '2016-01-01' and '2016-05-01' and
                        t2.section = 'KA'
                 );

为了提高性能，您需要在 t1(部分、日期、协议(protocol)) 上建立索引。和t2(协议(protocol)、部分、日期)。