Question

我有两个基本相同代码的版本。（见下文）版本1运行时间为2秒，版本2运行时间为.5 - .6秒。目前有1000万行来自我选择的地方，但这个数字上升得非常快。如果可能的话，我想更低。问题是我使用的是版本2，我需要调用30次（不同的状态，不同的用户名等），最终的数字仍然太大而不能满足我的需要。我可以使用第三个版本吗？或者还有其他方法可以让它更快吗？或者我唯一能做的就是玩索引。

基本上所有这些计数都将显示在Web应用程序中访问量最大的屏幕上，当1000个用户同时使用系统时，30 * .5秒听起来有点太多了。

版本1

aerospike@2.0.3

第2版

declare @a1 datetime; set @a1 = GETDATE()

declare @int1 INT,@int2 INT,@int3 INT,@int4 INT,@int5 INT,@int6 INT,@int7 INT,@int8 INT

select @int1 = COUNT(Id) from ToDos where StatusId = 1 and stringUserId = 'a'
select @int2 = COUNT(Id) from ToDos where StatusId = 1 and stringUserId = 'b'
select @int3 = COUNT(Id) from ToDos where StatusId = 1 and stringUserId = 'c'
select @int4 = COUNT(Id) from ToDos where StatusId = 1 and stringUserId = 'd'
select @int5 = COUNT(Id) from ToDos where StatusId = 1 and stringUserId = 'e'
select @int6 = COUNT(Id) from ToDos where StatusId = 1 and stringUserId = 'f'
select @int7 = COUNT(Id) from ToDos where StatusId = 1 and stringUserId = 'g'
select @int8 = COUNT(Id) from ToDos where StatusId = 1 and stringUserId = 'h'

select @int1, @int2, @int3, @int4, @int5, @int6, @int7, @int8

SELECT DATEDIFF(MILLISECOND, @a1, GETDATE())

Answer 1

尝试条件计数。

select 
     @int1 = COUNT(CASE WHEN stringUserId = 'a' THEN 1 END), 
     @int2 = COUNT(CASE WHEN stringUserId = 'b' THEN 1 END), 
     @int3 = COUNT(CASE WHEN stringUserId = 'c' THEN 1 END), 
     @int4 = COUNT(CASE WHEN stringUserId = 'd' THEN 1 END), 
     @int5 = COUNT(CASE WHEN stringUserId = 'e' THEN 1 END), 
     @int6 = COUNT(CASE WHEN stringUserId = 'f' THEN 1 END), 
     @int7 = COUNT(CASE WHEN stringUserId = 'g' THEN 1 END), 
     @int8 = COUNT(CASE WHEN stringUserId = 'h' THEN 1 END)
from ToDos 
where StatusId = 1

仅供参考：我没有为ELSE添加CASE部分，因为默认情况下会返回NULL而COUNT不会计算空值

Answer 2

你可以尝试：

select a.* from (select stringUserId, count(stringUserId) as IDCount
from ToDos
where StatusId = 1 and stringUserId in ('a','b','c','d','e','f','g','h')
group by stringUserId) a
order by a.IDCount desc

通过

从订单中删除计数功能

计算性能优化

2 个答案: