timeSeriesRateToGrid

引入版本：v25.6

聚合函数，接受由时间戳和值构成的时间序列数据对，并在由起始时间戳、结束时间戳和步长定义的规则时间网格上，从这些数据计算类似 PromQL 的 rate。对于网格上的每个点，用于计算 rate 的样本会被限制在指定的时间窗口内。

注意

此函数为实验性功能，可通过将 allow_experimental_ts_to_grid_aggregate_function 设置为 true 来启用。

语法

timeSeriesRateToGrid(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 — 指定被考虑样本的最大“陈旧度”（单位：秒）。陈旧度窗口是一个左开右闭区间。UInt32

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 — 与该时间戳对应的时间序列值。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 rate 值。返回的数组对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 rate 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 timeSeriesRateToGrid(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
);

┌─timeSeriesRateToGrid(start_ts, end_ts, step_seconds, window_seconds)(timestamp, value)─┐
│ [NULL,NULL,0,0.06666667,0.1,0.083333336,NULL,NULL,0.083333336]                        │
└───────────────────────────────────────────────────────────────────────────────────────┘

使用数组形式的参数

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 timeSeriesRateToGrid(start_ts, end_ts, step_seconds, window_seconds)(timestamps, values);

┌─timeSeriesRateToGrid(start_ts, end_ts, step_seconds, window_seconds)(timestamps, values)─┐
│ [NULL,NULL,0,0.06666667,0.1,0.083333336,NULL,NULL,0.083333336]                          │
└─────────────────────────────────────────────────────────────────────────────────────────┘

timeSeriesRateToGrid​

timeSeriesRateToGrid