Extending Object-Oriented Systems with Roles (1994)
| Venue: | ACM Transactions on Information Systems |
| Citations: | 119 - 0 self |
BibTeX
@ARTICLE{Gottlob94extendingobject-oriented,
author = {G. Gottlob and M. Schrefl and B. Röck and Einzelergebnisse Materialien and Im Interesse and Georg Gottlob and Michael Schrefl and Brigitte Rock},
title = {Extending Object-Oriented Systems with Roles},
journal = {ACM Transactions on Information Systems},
year = {1994},
volume = {14},
pages = {268--296}
}
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Abstract
In many class-based object-oriented systems the association between an instance and a class is exclusive and permanent. Therefore these systems have serious difficulties in representing objects taking on different roles over time. Such objects must be reclassified any time they evolve (e.g., if a person becomes a student and later an employee). Class hierarchies must be planned carefully and may grow exponentially if entities may take on several independent roles. The problem is even more severe for object-oriented databases than for common object-oriented programming. Databases store objects over longer periods, during which the represented entities evolve. This article shows how class-based object-oriented systems can be extended to handle evolving objects well. Class hierarchies are complemented by role hierarchies, whose nodes represent role types an object classified in the root may take on. At any point in time, an entity is represented by an instance of the root and a...
