Statistical Aggregate Functions

Statistical aggregate functions enable you to perform statistical analysis on numeric data.

These functions are true aggregate functions in that they can compute values for a group of rows as determined by the query’s group by clause. As with other basic aggregate functions, such as max or min, computation ignores null values in the input. Also, regardless of the domain of the expression being analyzed, all variance and standard deviation computation uses the Institute of Electrical and Electronic Engineers (IEEE) double-precision, floating-point standard.

If the input to any variance or standard deviation function is the empty set, then each function returns a null value. If the input to any variance or standard deviation function is a single value, then each function returns 0.

Statistical aggregate functions are similar to the avg aggregate function in that:

Unlike the avg aggregate function, however, the results are:

Related concepts
Aggregate Functions