STDDEV_SAMP [Aggregate]
Evaluates the statistical sample standard deviation for each member of the group. The return value is the same as the square root of VAR_SAMP
:
STDDEV_SAMP(expression) = SQRT(VAR_SAMP(expression))
Behavior Type
Syntax
STDDEV_SAMP ( expression )
Parameters
expression |
Any |
Related Functions
STDDEV_SAMP
is semantically identical to nonstandard functionSTDDEV
, which is provided for compatibility with other databases.- This aggregate function differs from analytic function
STDDEV_SAMP
, which computes the statistical sample standard deviation of the current row with respect to the group of rows within a window. -
When
VAR_SAMP
returnsNULL
,STDDEV_SAMP
returnsNULL
.
Examples
The following example returns the statistical sample standard deviation for each household ID from the customer
dimension table.
=> SELECT STDDEV_SAMP(household_id) FROM customer_dimension; stddev_samp ------------------ 8651.50842400771 (1 row)