Entity-relationship consistency for relational schemas

  • Johann A. Makowsky
  • Victor M. Markowitz
  • Nimrod Rotics
Contributed Papers
Part of the Lecture Notes in Computer Science book series (LNCS, volume 243)


We investigate the significance of requiring from a relational schema to comply with an entity-relationship structure. Relational database schemas here consist of traditional relational schemas together with key and inclusion dependencies. Such schemas are said to be entity-relationship (ER) consistent, either if they are the translate of, or if it is possible to translate them into, entity-relationship diagrams. An algorithm is presented which decides if a schema is ER-consistent and its complexity is discussed. ER-consistency expresses information structure normalization just as relational normal forms represent data representation normalization. For ER-consistent relational schemas we propose an Entity-Relationship Normal Form, and present the corresponding normalization procedure. ER-consistency expresses the capability of relational schemas to model information oriented systems. ER-consistent relational schemas allow the direct use of ER oriented query and update languages within the relational model.


Normal Form Relational Model Relational Schema Attribute Compatibility Natural Language Sentence 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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  1. [1]
    C. Beeri and M.Y. Vardi, "A note on decompositions of relations databases", ACM SIGMOD Record 12,1, Oct. 1981, pp. 33–37.Google Scholar
  2. [2]
    P.P. Chen, "The entity-relationship model-towards a unified view of data", ACM Trans. on Database Systems 1,1 (March 1976), pp. 9–36.Google Scholar
  3. [3]
    E.F. Codd, "Extending the relational database model to capture more meaning", ACM Trans. on Database Systems 4,4 (Dec 1979), pp. 397–434.Google Scholar
  4. [4]
    E.F. Codd, "Relational databases: A practical foundation for productivity", Comm. ACM 25,2 (Feb 1982), pp. 109–117.Google Scholar
  5. [5]
    S.S. Cosmadakis and P.C. Kanellakis, "Equational Theories and Database Constraints", in Proc 17th ACM Symposium on Theory of Computing, 1985, pp. 273–284.Google Scholar
  6. [6]
    M.A. Casanova and J.E. Amaral de Sa, "Mapping uninterpreted schemes into entity-relationship diagrams: two applications to conceptual schema design", IBM Journal of Research and Development 28, 1 (Jan 1984), pp. 82–94.Google Scholar
  7. [7]
    M.A. Casanova and V.M.P. Vidal, "Towards a sound view integration methodology", Proc of Second ACM Symposium on Principles of Database Systems, 1983, pp. 36–47.Google Scholar
  8. [8]
    A. Klug, "Entity-relationship views over uninterpreted enterprise schemas", Entity-Relationship Approach to Systems Analysis and Design, Chen, P.P.(ed.), North-Holland, 1980, pp. 39–59.Google Scholar
  9. [9]
    H. Mannila and K-J. Raiha, "Inclusion dependencies in database design", Proc of Second Conf. on Data Engineering, 1986, pp. 713–718.Google Scholar
  10. [10]
    J.C. Mitchell, "The implication problem for functional and inclusion dependencies", Information and Control 56,3 (March 1983), pp. 154–173.Google Scholar
  11. [11]
    N. Rotics, A unifying approach to the entity-relationship and relational data models, M.Sc. Thesis, Computer Science Dept, Technion, Israel, June 1985.Google Scholar
  12. [12]
    E. Sciore, "Inclusion dependencies and the universal instance", in Proc. 1983 ACM Symposium on Principles of Database Systems, 1983, pp. 48–57.Google Scholar
  13. [13]
    D.C. Tsichritzis and F.H. Lochovsky, Data models. Prentice-Hall, 1982.Google Scholar
  14. [14]
    J.D. Ullman, Principles of database systems (second edition), Computer Science Press, 1982.Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1986

Authors and Affiliations

  • Johann A. Makowsky
    • 1
  • Victor M. Markowitz
    • 1
  • Nimrod Rotics
    • 1
  1. 1.Computer Science DepartmentTechnion Israel Institute of TechnologyHaifa

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