Preserving Semantics of the Whole-Part Relationships in the Object-Relational Databases

A conceptual data model that is created for example in UML (OMG 2003) can contain aggregation and composition relationships between entity types. This article describes how to preserve the semantics of this kind of relationships in a database that is created by the Object-Relational Data-base Management System which implements the prescriptions, proscrip-tions and suggestions of The Third Manifesto (Date and Darwen 2000). A lot of research about the semantics of the aggregation and composi-tion relationships has been done by different authors. Examples of the re-cent research are works of Barbier et al. (2003) and Guizzardi (2005). Their view is that UML (at least prior to the version 2.0) doesn't define the semantics of this kind of relationships precisely enough. Therefore we use instead the concept "whole-part relationship" in this article. Barbier et al. (2003) list and explain primary and secondary characteristics of the whole-part relationships. We use the values of some of the secondary characteris-tics in order to choose between the database design alternatives. Database Management System (DBMS) can’t "understand" semantics of a relationship the same way as humans do - based on the names of a rela-tionship and its participants (Date and McGoveran 1994). But DBMS is able to understand and enforce structural and operational properties of the relationships and objects which participate in these relationships (Zhang et al. 2001). Underlying data model of a DBMS determines the extent of

[1]  Norbert Ritter,et al.  Enriched relationship processing in object-relational database management systems , 2001, Proceedings of the Third International Symposium on Cooperative Database Systems for Advanced Applications. CODAS 2001.

[2]  Brian Henderson-Sellers,et al.  Formalization of the Whole-Part Relationship in the Unified Modeling Language , 2003, IEEE Trans. Software Eng..

[3]  J. Wenny Rahayu,et al.  Implementation of object-oriented association relationships in relational databases , 1998, Proceedings. IDEAS'98. International Database Engineering and Applications Symposium (Cat. No.98EX156).

[4]  David Taniar,et al.  Mapping methods and query for aggregation and association in object-relational database using collection , 2004, International Conference on Information Technology: Coding and Computing, 2004. Proceedings. ITCC 2004..

[5]  C. J. Date,et al.  Foundation for Future Database Systems: The Third Manifesto , 2000 .

[6]  Trudy Pelzer,et al.  SQL-99 Complete, Really , 1999 .

[7]  Esperanza Marcos,et al.  Aggregation and Composition in Object-Relational Database Design , 2001 .

[8]  David Taniar,et al.  Preserving Aggregation in an Object-Relational DBMS , 2002, ADVIS.

[9]  C. J. Date,et al.  A new database design principle , 1994 .

[10]  Giancarlo Guizzardi,et al.  Ontological foundations for structural conceptual models , 2005 .

[11]  David Taniar,et al.  Composition in Object-Relational Database , 2005, Encyclopedia of Information Science and Technology.

[12]  Terry Halpin.  Modeling Collections in UML and ORM , 2000 .

[13]  Diane C. P. Smith,et al.  Database abstractions: aggregation , 1977, CACM.

[14]  Christian Soutou.  Modeling relationships in object-relational databases , 2001, Data Knowl. Eng..

[15]  E. F. Codd,et al.  A relational model of data for large shared data banks , 1970, CACM.

[16]  Stéphane Bressan,et al.  Introduction to Database Systems , 2005 .