clickhouse 计算平均值

Question

我有两个字段，一个是时间戳，另一个是网络字节的总和。就像这样：

timestamp      network_in_bytes
1551196802144   1
1551196802145   5 
1551196802147   18 
1551196802158   80

我要计算(B>A)

avg_network_in_bytes=(network_in_bytes_B-network_in_bytes_A)/(timestamp_B-timestamp_A). 

如何获得 avg_network_in_bytes？

Answer 1

看看这个功能runningDifference

你可以尝试做这样的事情：

select 
  timestamp,
  network_in_bytes,
  runningDifference(timestamp) as timestamp_diff,
  runningDifference(network_in_bytes) as bytes_diff,
  bytes_diff / timestamp_diff
from (
  select
    timestamp,
    network_in_bytes
  from table
  order by timestamp 
)