mysql 百万数据库 count 1秒内出结果

Question

sql1:

SELECT
            count(*)
        FROM
            t_order T  FORCE INDEX(cc)
        where
            T.del_status = '0'
            and T.is_project_order = '0'
            and T.firstperson = ''
            AND T.serverUserId = 'cdbcd902dbe411e89c777cd30ae00302

执行计划：

sql2:

select 
            count(T.id)
        from t_order T 
        where
        T.is_project_order = '0'
            and T.del_status = '0'
            and T.`status` not in ( 'ORDERCOMPLETE')

执行计划：

t_order表 索引

请教如何优化到1s内

目前百万数据库中执行下来是2s多

Answer 1

SELECT count(1) FROM (SELECT T.id from  from t_order T WHERE  T.is_project_order = '0' and T.del_status = '0'
 and T.`status` not in ( 'ORDERCOMPLETE'))

    加全覆盖索引 也就是说 把where子句后面条件涉及到的列 按照从左到右的顺序添加到索引中