Integration of object-oriented programming languages and database systems in KOPERNIK

KOPERNIK is an object-oriented database system, that allows uniform specification of database requests and application programs. The user interface is based on Smalltalk, and the object-oriented data model is represented in terms of classes and messages. Techniques are discussed for implementing such a model on top of an underlying relational database system. Those parts of application programs that cannot be translated into a relational language are handled by a Smalltalk processor. The semantics of the database requests is defined in terms of a meta-model and meta-messages, using an object-oriented approach. Hence we derive rules for translation of database requests into SQL queries over a binary relational view, introduced as an intermediate level between the underlying database and our conceptual view.