.-ALL------. >>-STDDEV--(----+----------+--expression--)-------------------->< '-DISTINCT-'
The schema is SYSIBM.
The STDDEV function returns the standard deviation of a set of numbers.
The argument values must be numbers.
The data type of the result is double-precision floating point. The result can be null.
The function is applied to the set of values derived from the argument values by the elimination of null values. If DISTINCT is specified, duplicate values are eliminated.
If the function is applied to an empty set, the result is a null value. Otherwise, the result is the standard deviation of the values in the set.
The order in which the values are aggregated is undefined, but every intermediate result must be within the range of the result data type.
Example:
SELECT STDDEV(SALARY) INTO :DEV FROM EMPLOYEE WHERE WORKDEPT = 'A00'
Results in DEV being set to approximately 9938.00 when using the sample table.