AWS Timestream：不支持给定的相关子查询

Question

select host, time as currentTime, floor((1 - (
  select sum(measure_value::double)
    from "DendroTimestreamDB"."hostMetrics"
    where cpuMode = 'idle'
    and time <= h.time
    group by host
) / ((
  select sum(measure_value::double)
    from "DendroTimestreamDB"."hostMetrics"
    where cpuMode = 'idle'
    and time <= h.time
    group by host
) + (
  select sum(measure_value::double)
    from "DendroTimestreamDB"."hostMetrics"
    where cpuMode = 'system'
    and time <= h.time
    group by host
) + (
  select sum(measure_value::double)
    from "DendroTimestreamDB"."hostMetrics"
    where cpuMode = 'user'
    and time <= h.time
    group by host
))) * 100) as utilization
from "DendroTimestreamDB"."hostMetrics" h
group by host, time

返回错误line 20:3: Given correlated subquery is not supported 但根据Timestream subquery support

Timestream 查询语言支持相关子查询和其他子查询。

列：

cpu模式， 主持人， 设备， 处理器代码， 集电极， measure_value::double, 测量名称， 时间，

样本数据：

空闲，MacBook-Pro.local，-，0，cpu，115950.13，cpu_seconds_total，2021-04-29 13:46:11.000000000

期望的输出：

主持人， 时间， 利用率

MacBook-Pro.local 2021-04-29 13:47:56.000000000 15

MacBook-Pro.local 2021-04-29 13:47:41.000000000 16

MacBook-Pro.local 2021-04-29 13:47:26.000000000 19

我正在尝试使用公式 (1 - idleTime / totalTime) * 100 计算 CPU 利用率，但显然不支持这些相关的子查询。我只需要以不同的方式重写它吗？

在求和子查询中，我试图计算在主查询之前收到的度量值的总和，我正在使用 and time <= h.time 行来执行此操作，从而使查询相互关联，因此问题。

非常感谢

Answer 1

我很确定您想要条件聚合。我无法真正遵循逻辑，但组件似乎是这样的：

select host, time as currentTime,
       sum(sum(case when cpuMode = 'idle' then measure_value::double)) over (partition by host order by time)
       sum(sum(case when cpuMode = 'system' then measure_value::double)) over (partition by host order by time)
       sum(sum(case when cpuMode = 'user' then measure_value::double)) over (partition by host order by time)
from "DendroTimestreamDB"."hostMetrics" h
group by host, time