Expressions passed to this function must be one of the following data types:
BYTEINT, SMALLINT, INTEGER, BIGINT, DECIMAL/NUMERIC, FLOAT/REAL/DOUBLE PRECISION, NUMBER, CHAR, VARCHAR
You can also pass arguments with data types that can be converted to the above 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 normally used by Teradata Database. If an argument cannot be converted to the required data type following the UDF implicit conversion rules, it must be explicitly cast.