timeSeriesDeltaToGrid

引入版本：v25.6

该聚合函数接收由时间戳与数值构成的时间序列数据对，并在由起始时间戳、结束时间戳和步长描述的等间隔时间网格上，从这些数据中计算类似 PromQL 的 delta。对于网格上的每个点，计算 delta 时会考虑位于指定时间窗口内的样本。

注意

此函数为实验性功能，可通过设置 allow_experimental_ts_to_grid_aggregate_function=true 启用。

语法

timeSeriesDeltaToGrid(start_timestamp, end_timestamp, grid_step, staleness)(timestamp, value)

参数

start_timestamp — 指定网格的起始时间。UInt32 或 DateTime
end_timestamp — 指定网格的结束时间。UInt32 或 DateTime
grid_step — 指定网格的步长（单位：秒）。UInt32
staleness — 指定所考虑样本的最大陈旧度（单位：秒）。陈旧度窗口是一个左开右闭区间。UInt32

函数参数（Arguments）

timestamp — 样本的时间戳。可以是单个值或数组。UInt32 或 DateTime 或 Array(UInt32) 或 Array(DateTime)
value — 与时间戳对应的时间序列数值。可以是单个值或数组。Float* 或 Array(Float*)

返回值

返回在指定网格上的 delta 值。返回的数组在每个时间网格点包含一个值。如果在窗口内没有足够的样本来计算某个网格点的 delta 值，则该值为 NULL。Array(Nullable(Float64))

示例

使用单个时间戳-数值对的基本用法

WITH
    -- NOTE: the gap between 140 and 190 is to show how values are filled for ts = 150, 165, 180 according to window parameter
    [110, 120, 130, 140, 190, 200, 210, 220, 230]::Array(DateTime) AS timestamps,
    [1, 1, 3, 4, 5, 5, 8, 12, 13]::Array(Float32) AS values, -- array of values corresponding to timestamps above
    90 AS start_ts,      -- start of timestamp grid
    90 + 120 AS end_ts,  -- end of timestamp grid
    15 AS step_seconds,  -- step of timestamp grid
    45 AS window_seconds -- "staleness" window
SELECT timeSeriesDeltaToGrid(start_ts, end_ts, step_seconds, window_seconds)(timestamp, value)
FROM
(
    -- This subquery converts arrays of timestamps and values into rows of `timestamp`, `value`
    SELECT
        arrayJoin(arrayZip(timestamps, values)) AS ts_and_val,
        ts_and_val.1 AS timestamp,
        ts_and_val.2 AS value
);

┌─timeSeriesDeltaToGrid(start_ts, end_ts, step_seconds, window_seconds)(timestamp, value)─┐
│ [NULL,NULL,0,3,4.5,3.75,NULL,NULL,3.75]                                               │
└───────────────────────────────────────────────────────────────────────────────────────┘

使用数组类型参数

-- it is possible to pass multiple samples of timestamps and values as Arrays of equal size
WITH
    [110, 120, 130, 140, 190, 200, 210, 220, 230]::Array(DateTime) AS timestamps,
    [1, 1, 3, 4, 5, 5, 8, 12, 13]::Array(Float32) AS values,
    90 AS start_ts,
    90 + 120 AS end_ts,
    15 AS step_seconds,
    45 AS window_seconds
SELECT timeSeriesDeltaToGrid(start_ts, end_ts, step_seconds, window_seconds)(timestamps, values);

┌─timeSeriesDeltaToGrid(start_ts, end_ts, step_seconds, window_seconds)(timestamps, values)─┐
│ [NULL,NULL,0,3,4.5,3.75,NULL,NULL,3.75]                                                 │
└─────────────────────────────────────────────────────────────────────────────────────────┘

timeSeriesDeltaToGrid​

timeSeriesDeltaToGrid