Skip to main content
Early access 1.6.0 Calculate the change in a gauge during the time period specified by the bounds in the gauge aggregate. The bounds must be specified for the extrapolated_delta function to work. You can provide them as part of the original gauge_agg call, or by using the with_bounds function on an existing gauge aggregate.

​
Arguments

NameTypeDefaultRequiredDescription
summaryGaugeSummary-✔A gauge aggregate created using gauge_agg
methodTEXT-✔The extrapolation method to use. Not case-sensitive. The only allowed value is prometheus, for the Prometheus extrapolation protocol.

​
Returns

DOUBLE PRECISION: The extrapolated change in the gauge over the time period of the gauge aggregate.

​
Samples

Extrapolate the change in a gauge over every 15-minute interval. 
SELECT
    id,
    bucket,
    extrapolated_delta(
        with_bounds(
            summary,
            toolkit_experimental.time_bucket_range('15 min'::interval, bucket)
        ),'prometheus'
    )
FROM (
    SELECT
        id,
        time_bucket('15 min'::interval, ts) AS bucket,
        gauge_agg(ts, val) AS summary
    FROM foo
    GROUP BY id, time_bucket('15 min'::interval, ts)
) t;