SQL Aggregate Functions Overview of Aggregate Functions – Functions that evaluate all of the values of a column and return a single aggregate value. AVG – An aggregate function that returns the average of the values of the specified column. COUNT – An aggregate function that returns the number of rows in a table or a specified column. %DLIST – An aggregate function that creates an InterSystems IRIS list of values. JSON_ARRAYAGG – An aggregate function that creates a JSON format array of values. LIST – An aggregate function that creates a comma-separated list of values. MAX – An aggregate function that returns the maximum data value in a specified column. MIN – An aggregate function that returns the minimum data value in a specified column. STDDEV, STDDEV_SAMP, STDDEV_POP – Aggregate functions that return the statistical standard deviation of a data set. SUM – An aggregate function that returns the sum of the values of a specified column. VARIANCE, VAR_SAMP, VAR_POP – Aggregate functions that return the statistical variance of a data set. XMLAGG – An aggregate function that creates a concatenated string of values.