counter_zero_time()

Calculate the time when the counter value is predicted to have been zero

Since 1.3.0

Calculate the time when the counter value is predicted to have been zero. This is the x-intercept of the linear fit between counter value and time.

Samples

Estimate the time when the counter started

SELECT
    id,
    bucket,
    counter_zero_time(summary)
FROM (
    SELECT
        id,
        time_bucket('15 min'::interval, ts) AS bucket,
        counter_agg(ts, val) AS summary
    FROM foo
    GROUP BY id, time_bucket('15 min'::interval, ts)
) t

Arguments

The syntax is:

counter_zero_time(
    summary CounterSummary
) RETURNS TIMESTAMPTZ

Name	Type	Default	Required	Description
summary	CounterSummary	-	✔	A counter aggregate created using counter_agg

Returns

Column	Type	Description
counter_zero_time	TIMESTAMPTZ	The time when the counter value is predicted to have been zero