mean()

Calculate the exact mean from values in a tdigest

Since 1.0.0

Calculate the exact mean of the values in a tdigest aggregate. Unlike percentile calculations, the mean calculation is exact. This accessor allows you to calculate the mean alongside percentiles, without needing to create two separate aggregates from the same raw data.

Samples

Calculate the mean of the integers from 0 to 100.

SELECT mean(tdigest(data))
FROM generate_series(0, 100) data;

mean
------
50

Arguments

The syntax is:

mean(
  digest TDigest
) RETURNS DOUBLE PRECISION

Name	Type	Default	Required	Description
digest	TDigest	-	✔	The tdigest aggregate to extract the mean from

Returns

Column	Type	Description
mean	DOUBLE PRECISION	The mean of the values in the tdigest.