Refinement

In contrast of the bottom-up analysis which let us create a superobject, we may want to separate the Data objects into disk data objects and memory data objects. The splitting will avoid an additional parameter at object creation time that specifies which one of these two objects we want. But we see also that there is a high connectivity between this two type of objects. In fact the Data object is not a data store object but a manipulator of the data. A data store object, or really two data store objects are needed. These objects will have only Put and Get functionalities. They will either work on disk or in memory. The Data object as a manipulator of the data will have the data store object as internal data.