Description logics have powerful deductive capabilities but rely on a weakly structured model. Databases provide storage optimization
and offer better structuring capacities, especially within the object-oriented paradigm. We propose a model which offers the
deductive capabilities of description logics and the structuring possibilities of the object approach. We distinguish between
three types of classes : concrete classes, where objects are instantiated, virtual classes, which are subsets of concrete
classes, corresponding to database objectpreserving views, and abstract classes, which factor common properties of objects
from different concrete classes. A schema in this model can be translated into a description logics schema and into a database
schema. The former represents the deductive part and the latter deals with the storage aspect.