Object Views Constructed with an Object Algebra

We present a formal data model for views in Object DataBase Systems (ODBS) which is a continuationand a formalization of the work presented in [AK89, AB91, ADdS94, dS95a]. The main contribution of thispaper is the formalization of the views as a transformation mechanism for databases using a generalizationof referent proposed in [dS95b]. The view-based transformation is achieved in two steps: an extensionof the source base followed by a projection of the extended base. The extension and...