rate()

The rate of change of the counter over the observed time period. This is the raw or simple rate, equivalent to delta(summary) or time_delta(summary). After accounting for resets, the last value is subtracted from the first value and divided by the duration between the last observed time and the first observed time.

rate(
    summary CounterSummary
) RETURNS DOUBLE PRECISION

For more information about counter aggregation functions, see the hyperfunctions documentation.

SELECT
    id,
    rate(summary)
FROM (
    SELECT
        id,
        counter_agg(ts, val) AS summary
    FROM foo
    GROUP BY id
) t