To the extent that the set of temp-tables in a ProDataSet appears to reflect the tables of a single database, the ProDataSet can model and thus represent an abstraction of that database. Thus, a ProDataSet allows the application service to maintain an atomic subset of its data sources that it can pass as a unit to its clients and other services. As such, the ProDataSet is entirely separate from and can be managed independently of the data sources to which it is related. The data-relations of a ProDataSet can closely model the existing entity relations among its data sources using similar key relationships, or they can establish entirely different relationships among the temp-tables of the ProDataSet, as defined by the application service.