Simple Aggregate Functions

Simple aggregate functions, such as AVG, COUNT, MAX, MIN, and SUM summarize data over a group of rows from the database.

The groups are formed using the GROUP BY clause of the SELECT statement. These aggregates are allowed only in the select list and in the HAVING and ORDER BY clauses of a SELECT statement.

Note: With the exception of Grouping() functions, both the simple and unary aggregates can be used in a windowing function that incorporates a <window clause> in a SQL query specification (a window) that conceptually creates a moving window over a result set as it is processed.

See Reference: Building Blocks, Tables, and Procedures > SQL Functions > Aggregate functions.