authors |
Rasdorf, William J., Ulberg, Karen J. and Baugh, John W. Jr. |
year |
1987 |
title |
A Structure-Based Model of Semantic Integrity Constraints for Relational Databases |
source |
International Journal of Engineering with Computers. Springer-Verlag, Spring, 1987. vol. 2: pp. 31- 39 |
summary |
Database management systems (DBMSs) are in widespread use because of the ease and flexibility with which they enable users to access large volumes of data. The use of DBMSs has spread from its origin in business applications to scientific and engineering applications as well. As engineers rely more and more on the computer for data storage, our ability to manually keep track of relationships between data and to ensure data accuracy is severely limited. The inherent fluctuations in engineering design data as well as its large volume, increase the difficulty of doing so. Ensuring data accuracy through the use of integrity constraints which limit or constrain the values of the data is a central aspect of DBMS use. Enforcing constraints (to the extend possible) is a job for the DBMS. This alleviates some of the burden placed on the user and database administrator to maintain the integrity of the database. In addition, it enables integrity constraints to be conceptually centralized and made available for inspection and modification instead of being scattered among application programs. Despite their importance, however, capabilities for handling integrity constraints in commercial DBMSs are limited and they lack adequate integrity maintenance support. In addition, a comprehensive theoretical basis for such support-the role of a constraint classification, representation, invocation, and use methodology-has yet to be developed. This paper presents a formalism that classifies semantic integrity constraints based on the structure of the relational database model. Integrity constraints are characterized by the portion of the database structure they access, whether one or more relations, attributes, or tuples. Thus, the model is completely general, allowing the identification, definition, and arbitrary specification of any constraint on a relational database. It also provides a basis for the implementation of a database integrity subsystem. Examples of each type of constraint are illustrated using a small engineering database, and various implementation issues are discussed |
keywords |
civil engineering, relational database, constraints management |
series |
CADline |
references |
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last changed |
2003/06/02 13:58 |
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