Decomposition of relationships through pivoting

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Authors: Joachim Biskup, Ralf Menzel, Torsten Polle, Yehoshua Sagiv

Tags: 1996, conceptual modeling

In the literature there are several proposals to map entity-relationship schemas onto object-oriented schemas, but they only treat relationship sets naÏvely or restrict them to binary relationship sets. We follow a different approach in the treatment of relationship sets. Our goal is to let the designer specify relationships of any arity and then to employ semantic constraints to decompose relationships into smaller fragments. The semantic constraints in use are functional constraints, which are defined in the object-oriented framework. The decomposition process guided by functional constraints is similar to the decomposition process in the relational approach with functional dependencies, but it takes advantage of the features provided by the object-oriented data model. In object-oriented schemas it is possible to enforce a certain kind of functional constraints automatically, namely unary functional constraints.

Read the full paper here: https://link.springer.com/chapter/10.1007/BFb0019913