Consistency Management in Object-Oriented Databases

The paper presents concepts and ideas underlying an approach for consistency management in object oriented databases. In this approach constraints are structured as rst class citizens and stored in a meta-database called constraints catalog. When an object is created constraints of this object are retrieved from the constraints catalog and relationships between these constraints and the object are established. The structure of constraints has several features that enhance consistency management in OODBMS which do not exist in conventional approaches in a satisfactory way. These features are monitoring objects consistency at diierent levels of update granularity, integrity independence, eeciency of constraints maintenance, controlling inconsistent objects, enabling and disabling of constraints globally to all objects of database as well as locally to individual objects, and the possibility of declaring constraints on individual objects. All these features are provided by means of basic notations of OO data models.