A Primer on Object Role Modeling

The originators and proponents of object role modeling assert that another layer, the conceptual schema, should be inserted between the external and logical schemas. The basic notions are that 1) the relationships among data elements can be described according to a relatively simple set of criteria, and 2) the resulting descriptions then determine, in a mathematical sense, a fully normalized logical schema. In other words, a relatively simple algorithm can translate a correctly described conceptual model into a 5th normal form logical model. Full normalization of a logical model not only ensures that it is correctly designed in a mathematical sense, but also brings practical benefits to database development and management.