优化sql，使用两个完整表扫描CTE'；s

我正在寻找对以下查询的改进，感谢您的任何意见

with cteA as (
        select name, count(1) as "A" 
        from mytable 
        where y="A"
        group by name
    ),
    cteB as (
            select name, count(1) as "B" 
            from mytable 
            where y="B"
            group by name

    )
    SELECT  cteA.name as 'name',
        cteA.A as 'count x when A',
        isnull(cteB.B as 'count x when B',0)
    FROM
    cteOne 
    LEFT OUTER JOIN 
    cteTwo
    on cteA.Name = cteB.Name
    order by 1 

---

最简单的答案是：

select name, y, count(*)
from mytable
where y in ('A','B')
group by name, y

---

如果在列中需要Y行值，可以使用轴将Y行值移动到列中。

当然，如果为字段Y和名称编制索引，也会很有帮助。

select name, y, count(*)
from mytable
where y in ('A','B')
group by name, y