Approaches to Deductive Object-Oriented Databases

This paper is concerned with the problem of combining deductive and object-oriented features to produce a deductive object-oriented database system which is comparable to those currently available under the relational view of data modelling not only in its functionality but also in the techniques employed in its construction and use. Under this assumption, we highlight the kinds of issues that have to be tackled for a similar research strategy to produce comparable results. We motivate our terms of comparison, characterise three broad approaches to deductive object-oriented databases and introduce the notion of language convergence to help in the characterisation of some shortcomings that have been perceived in them. Three proposals that have come to light in the past three years are looked into in some detail, insofar as they exemplify some of the positions in the space of choices we have defined. The main contribution of the paper is towards a characterisation of the language convergence property of deductive database languages which has a key role in addressing critiques of the deductive and object-oriented database research enterprise. We assume a basic familiarity with notions from deductive databases and from object-oriented databases