15.00 - Function Class Clause - Teradata Database

Teradata Database SQL Data Definition Language Detailed Topics

Teradata Database
Programming Reference

Function Class Clause

This optional clause specifies the class of function being defined. Specify it only for aggregate functions.

The aggregate function is invoked for each group in a SELECT statement that requires aggregation and computes a single value for each group it is called for. You can specify an aggregate UDF anywhere you can specify a built‑in aggregate function.

A function of one class cannot have the same name as a function of another class within the same database, even if their parameters differ. Overloading function names is only supported within the same class of a function.

This clause is a Teradata extension to the ANSI SQL:2011 standard.