Deterministic Characteristics Clause: CREATE FUNCTION and REPLACE FUNCTION (External Form) - Teradata Vantage

This optional clause declares whether the function returns the same results for identical inputs or not.

Vantage must evaluate each row selected by a non-deterministic UDF condition individually because the evaluation of the function can change for each row selected within a query (this qualification includes both specifying NOT DETERMINISTIC explicitly and not specifying DETERMINISTIC, because NOT DETERMINISTIC is the default option for the clause). A predicate that includes a non-deterministic UDF specified on an index causes an all-AMP operation despite the index having been specified in the predicate.