17.10 - Function Class Clause - Advanced SQL Engine - Teradata Database

Teradata Vantage™ - SQL Data Definition Language Detailed Topics

Product
Advanced SQL Engine
Teradata Database
Release Number
17.10
Release Date
July 2021
Content Type
Programming Reference
Publication ID
B035-1184-171K
Language
English (United States)

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.