THE UFO DATABASE MODEL : DEALING WITH IMPERFECT INFORMATION

The ultimate goal of the research discussed in this paper, is the design of a database model with a true flavour of reality. Because the real world is not always perfect and, moreover, because the world of the application model is not an ideal reflection of the real world, the “ideal” database model should be able to process imperfect information about the database application in a convenient and flexible way. This paper describes an effort to reach this goal with the UFO database model. UFO extends an object-oriented database model, which defines flexible modelling concepts, with capabilities to handle major forms of imperfection in information. The extended concepts cover all layers of the model and are explained here in detail. A practical implementation via an interface to an extended relational database model is also outlined.