STDDEV_POP [Analytic]
Computes the statistical population standard deviation and returns the square root of the population variance within a window. The STDDEV_POP()
return value is the same as the square root of the VAR_POP()
function:
STDDEV_POP( expression ) = SQRT(VAR_POP( expression ))
When VAR_POP
returns null, STDDEV_POP
returns null.
Behavior Type
Syntax
STDDEV_POP ( expression ) OVER ( ... [ window-partition-clause ] ... [ window-order-clause ] ... [ window-frame-clause ] )
Parameters
expression |
Any |
OVER()
|
Examples
The following example returns the population standard deviations of salaries in the employee dimension table by job title Assistant Director:
=> SELECT employee_last_name, annual_salary, STDDEV_POP(annual_salary) OVER (ORDER BY hire_date) as "stddev_pop" FROM employee_dimension WHERE job_title = 'Assistant Director'; employee_last_name | annual_salary | stddev_pop --------------------+---------------+------------------ Goldberg | 61859 | 0 Miller | 79582 | 8861.5 Goldberg | 74236 | 7422.74712548456 Campbell | 66426 | 6850.22125098891 Moore | 66630 | 6322.08223926257 Nguyen | 53530 | 8356.55480080699 Harris | 74115 | 8122.72288970008 Lang | 59981 | 8053.54776538731 Farmer | 60597 | 7858.70140687825 Nguyen | 78941 | 8360.63150784682