A Pragmatic Method for the Integration of Higher-Order Entity-Relationship Schemata

One of the challenges in practical information system development is to find suitable methods for schema integration. Schema integration aims at replacing a set of existing schemata by a single new one. In this case there is a need to guarantee that with respect to information capacity the new schema dominates or is equivalent to the old ones. We develop formal transformation rules for schema integration. These rules rely on the Higher-order Entity-Relationship model and its theory of schema equivalence and dominance. The rules are embedded in a pragmatic method telling how they should be applied for integration. The method has been applied to various schemata of realistic size.