Consistency management in object-oriented databases

The paper presents concepts and ideas underlying an approach for consistency management in object-oriented (OO) databases. In this approach constraints are considered as first 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 OO database management systems which do not exist in conventional approaches in a satisfactory way. This includes: monitoring object consistency at different levels of update granularity, integrity independence, and efficiency of constraints maintenance; controlling inconsistent objects; enabling and disabling constraints, globally to all objects or locally to individual objects; and declaring constraints on individual objects. All these features are provided by means of basic notations of OO data models. Copyright (C) 2001 John Wiley & Sons, Ltd.