This paper focuses on a formal approach* for advanced database modeling and design. It is based on the IFO_2 model, an extension of the semantic model IFO defined by S. Abiteboul and R. Hull. It preserves the acquired strengths of the semantic approaches, whilst integrating concepts of the object paradigm. To model an IFO_2 schema, the structural part of the model including concepts such as alternative, composition, grouping for building complex objects and semantic constraints is formally specified. Furthermore, the definitions of update facilities necessary to modify and perfect IFO_2 schemas arc specified through change rules. Finally, in order to design a database schema, an IFO_2 schema is translated, in an automatical way, into an existing target (implemenlable) model. As an illustration, we present a translation from the IFO_2 model into the O_2 one. The result is a new coherent and formal approach which is useful in overcoming some of the difficulties in the specification and design of object-oriented applications.
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