The rules for granting privileges on UDFs are identical to those for macros except for the CREATE FUNCTION and EXECUTE FUNCTION privileges, as documented in the following table, which explains which UDF-related privileges are granted explicitly or not:
All newly created external UDFs are performed in protected mode by default. This is also true for all newly created methods and external procedures. UDFs do not run in modes.
The ALTER FUNCTION privilege should be restricted to DBAs exclusively. Its intent is to permit a user to perform the ALTER FUNCTION statement, which can be used to change the execution mode of a UDF. Changing the execution mode for a UDF from PROTECTED to NOT PROTECTED, for example, is not an act that should be performed without exercising extreme caution.
For more information see “ALTER FUNCTION,” “ALTER METHOD,” and ALTER PROCEDURE” in Teradata Vantage™ - SQL Data Definition Language Syntax and Examples, B035-1144.