The result predefined data type returned by the external function that is to be converted to the type specified by the RETURNS clause.
For example:
...RETURNS DECIMAL(9,5) CAST FROM FLOAT...
You cannot specify a character server data set of KANJI1. Otherwise, the system returns an error to the requestor.
Whenever a LOB that requires data type conversion is passed to a method, the LOB must first be materialized for the conversion to occur.