In this paper, we present a view model for object-oriented databases that extends in various directions view models typical of relational databases. In particular, the definition language allows views to be defined that augment class definitions (by adding properties and methods), and that support a wide spectrum of schema modifications. Therefore, views represent a unified mechanism able to provide several functions, such as query shorthand, definitions of dynamic sets and partitions of classes, authorizations, schema changes and versions, object perspectives.
The work reported in this paper has been partially supported by the Consiglio Nazionale delle Ricerche under the project Progetto Finalizzato Sistemi Informatici e Calcolo Parallelo — Sottoprogetto 5 (Sistemi Evoluti per Basi di Dati.