As user-defined function invoked in the FROM clause of a SELECT statement, a Table UDF returns a table to the statement.
See the TABLE option of the FROM clause in Teradata Vantage™ - SQL Data Manipulation Language, B035-1146.
ANSI Compliance
This statement is ANSI SQL:2011 compliant, but includes non-ANSI Teradata extensions.
The requirement that parentheses appear when the argument list is empty is a Teradata extension to preserve compatibility with existing applications.
Required Privileges
You must have EXECUTE FUNCTION privileges on the function or on the database containing the function.
To invoke a table UDF that takes a UDT argument or returns a UDT, you must have the UDTUSAGE privilege on the SYSUDTLIB database or on the specified UDT.