Release 10.1A: OpenEdge Data Management:
SQL Reference

Aggregate functions

Aggregate functions calculate a single value for a collection of rows in a result table. If the function is in a statement with a GROUP BY clause, it returns a value for each group in the result table. Aggregate functions are also called set or statistical functions. Aggregate functions cannot be nested.

The aggregate functions are:

AVG
COUNT
MAX
MIN
SUM