The DETERMINIST statement determines whether the return value is based solely on the input values or if they could depend on additional, varying data. 
[NOT] DETERMINISTIC
where:
DETERMINISTIC
specifies that the return value or operation is dependent solely on the input values. Specify this statement if the same input values always generate the same output.
NOT DETERMINISTIC
specifies that the return value of the function could depend on variables, such as data read during the evaluation, random values, or the current time. If the same input parameters may not always generate the same output, specify this statement or rely on the default behavior.

Note that this statement is optional. The default is NOT DETERMINISTIC.