Abstract
Absence of redundancy is an important quality of ER schemata. Adequate treatment of derivable data, in addition to observing normal forms, is necessary to achieve nonredundant databases. According to the source of their meaning to the user, there are two types of derivable data which should be treated differently. M-derivable data are redundant und ought to be removed from the ER schema, whereas s-derivable data add knowledge to the database and may be kept in the schema if they are distinguished from original data. However, there are some classes of derivable data, which are often brought into an ER schema unintentionally and are hard to detect. We introduce an important class of such data, compositions of relationship sets, and define them formally. In addition, we suggest methods which might help the database designer to find compositions in the schema.
This is a preview of subscription content, log in via an institution to check access.
Preview
Unable to display preview. Download preview PDF.
References
Batini, C., Lenzerini, M., Navathe, S.B.: A Comparative Analysis of Methodologies for Database Schema Integration, ACM Computing Surveys, Vol. 18, Dec. 1986
Batini, C., Ceri, S., Navathe, S.B.: Conceptual Database Design, Redwood City, Calif.: Benjamin/Cummings, 1992
Chen, P.P.S.: “The Entity-Relationship Model: Toward a Unified View of Data”, ACM TODS 1, No. 1 (March 1976)
Codd, E.F.: “A Relational Model of Data for Large Shared Data Banks”, CACM 13(6), pp. 377–387
Date, C.J.: An Introduction to Database Systems, Vol. I, 5th edition, Reading, Mass.: Addison-Wesley, 1990
Elmasri, R., Navathe, S.B.: Fundamentals of Database Systems, Redwood City, California: Benjamin/ Cummings, 1989
Maier, D.: The Theory of Relational Databases, Rockville, Maryland: Computer Science Press, 1983
Rauh, O.: “Gütekriterien für die semantische Datenmodellierung”, HMD (Theorie und Praxis der Wirtschaftsinformatik), Nr. 158, März 1991
Rauh, O.: “Some rules for handling derivable data in conceptual data modeling”, in Database and Expert Systems Applications (A.M. Tjoa and I. Ramos, eds.), Wien: Spcycleer-Verlag, 1992
Rauh, O., Stickel, E.: “Beziehungsprobleme: Zur Quantifizierung von Beziehungsarten im ER-Modell”, it (Informationstechnik), Nr. 6, Dez. 1992
Stickel, E.: Datenbankdesign, Wiesbaden: Gabler, 1991
Ullman, J.D.: Principles of Database and Knowledge-Base Systems, Vol. I, Rockville, Maryland: Computer Science Press, 1988
Wong, E., Katz, R.H.: “Logical Design and Schema Conversion for Relational and DBTG Databases, in Chen, P.P.S. (ed.), Entity-Relationship Approach for Systems Analysis and Design, Amsterdam: North-Holland, 1980
Author information
Authors and Affiliations
Editor information
Rights and permissions
Copyright information
© 1994 Springer-Verlag Berlin Heidelberg
About this paper
Cite this paper
Rauh, O., Stickel, E. (1994). Searching for compositions in ER schemes. In: Elmasri, R.A., Kouramajian, V., Thalheim, B. (eds) Entity-Relationship Approach — ER '93. ER 1993. Lecture Notes in Computer Science, vol 823. Springer, Berlin, Heidelberg. https://doi.org/10.1007/BFb0024358
Download citation
DOI: https://doi.org/10.1007/BFb0024358
Published:
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-540-58217-5
Online ISBN: 978-3-540-48575-9
eBook Packages: Springer Book Archive