When built-in functions cannot satisfy your needs, create user-defined functions (UDFs)
which are extensions to Teradata SQL. There are two types of UDFs: scalar UDF and aggregate UDF. UDFs are created in much the same way as other Teradata Database objects. Use DDL
and DCL statements to create and manage the UDF, as well as grant access to it after
it is created. A UDF can be local to a database or globally accessible to all users.
For more information on UDFs and UDTs:
See Data Dictionary.
For a white paper that provides an overview of user-defined types, go to Teradata.com. In the Search box, type User-defined Types.
For a white paper that provides a high-level overview of the UDF feature, go to Teradata.com. In the Search box, type Teradata User Defined Functions.
See the Teradata Orange Book, Working with User-Defined Types and User-Defined Methods with the Teradata Client
Products. For information on how to access Orange Books, see Teradata Tools and Utilities Release Definition. This Teradata Orange Book will not be updated past the Teradata Tools and Utilities
Note: Locations cited in this section are current at the time of this writing, but might change.