stddev()

Calculate the standard deviation from a one-dimensional statistical aggregate

Since 1.3.0

Calculate the standard deviation from the values in a statistical aggregate.

Samples

Calculate the standard deviation of a sample containing the integers from 0 to 100:

SELECT stddev(stats_agg(data))
  FROM generate_series(0, 100) data;

stddev_y
--------
29.3002

Arguments

The syntax is:

stddev(
  summary StatsSummary1D,
  [ method TEXT ]
) RETURNS DOUBLE PRECISION

Name	Type	Default	Required	Description
summary	StatsSummary1D	-	✔	The statistical aggregate produced by a stats_agg call
method	TEXT	sample	-	The method used for calculating the standard deviation. The two options are population and sample, which can be abbreviated to pop or samp

Returns

Column	Type	Description
stddev	DOUBLE PRECISION	The standard deviation of the values in the statistical aggregate