A close look at the IFO data model

Abstract

The IFO data model was proposed by Abiteboul and Hull [Abiteboul 87] as a formalized semantic database model. It has been claimed by the authors that the model subsumes the Relational model [Codd 70], the Entity-Relationship model [Chen 76], the Functional Data Model [Kerschberg 76] and virtually all of the structured aspects of the Semantic Data Model [Hammer 81], the INSYDE Model [King 85], and the Extended Semantic Hierarchy Model [Brodie 84].This paper examines the IFO data model as presented in [Abiteboul 87], compares it to other models, and thus concludes that the IFO data model is actually a subset of the Semantic Data Model proposed by Hammer in [Hammer 81]. The paper also shows that the IFO data model has failed to support concepts that are essential to both the E-R model and the Semantic Data Model which are claimed to be subsumed by the IFO model.Section 2 discusses the three IFO constructs, objects, fragments, and relationships. The mapping of these constructs to constructs in the Semantic Data Model is established as an informal proof of the result that the IFO model is subsumed by the SDM.Section 3 lists constructs supported by the Entity-Relationship model [Chen 76, Teorey 86] as will as constructs supported by SDM [Hammer 81]that the IFO data model fails to support.