Transformation of special multiplicity constraints — Comparison of possible realizations

This paper deals with the transformation of binary relationships from Platform Independent Model (PIM) in UML to Platform Specific Model (PSM) for relational databases from the point of view of Model Driven Development (MDD). The paper summarizes the transformation of a binary relationship with multiplicity constraints and focuses on problems of the current approach for such transformations. In this paper, we deal with the source class optionality that is usually omitted during the transformation. We propose three various possible realizations for the optionality constraint to be used in the transformation of a PIM to a PSM. We also present some experiments to demonstrate that our approach to the optionality constraint realization is equivalent in execution time to the current approach of omitting this constraint during the transformation while providing better consistency control. Finally, we generalize our proposed solution to be used for special multiplicity values used in a PIM.