Expressions passed to this function must have one of the following data types:
CHAR, VARCHAR, or CLOB
You can also pass arguments with data types that can be converted to the preceding types using the implicit data type conversion rules that apply to UDFs.
The UDF implicit type conversion rules are more restrictive than the implicit type conversion rules typically used by Vantage. An argument that cannot be converted to the required data type following the UDF implicit conversion rules must be explicitly cast.