Authors: Sven Hartmann
Tags: 1998, conceptual modeling
In the entity-relationship model, cardinality constraints are frequently used to specify dependencies between entities and relationships. They impose lower and upper bounds on the cardinality of relationships an instance of a fixed type may participate in. However, for certain applications it is not enough to prescibe only bounds, but it is necessary to specify the exact set of permitted cardinalities. This leads to the concept of int-cardinality constraints as proposed by Thalheim [14]. Different from ordinary cardinality constraints this concept allows gaps in the sets of permitted cardinalities. Our objective is to investigate the consistency of a set of int-cardinality constraints for a database scheme, i.e. the question whether there exists a fully-populated database instance satisfying all the given int-cardinality constraints.Read the full paper here: https://link.springer.com/chapter/10.1007/978-3-540-49524-6_12
