A rigorous approach to schema restructuring

  • Vânia M. P. Vidal
  • Marianne Winslett
Reverse Engineering and Schema Transformation I
Part of the Lecture Notes in Computer Science book series (LNCS, volume 1021)


A problem of schema integration is that one cannot directly merge concepts that are intuitively the same but have different representations. This problem can be solved by performing schema transformations to conform the views being integrated so that merging of classes and attributes becomes possible (schema restructuring). Previously, researchers have approached schema restructuring in an informal manner, offering heuristics to guide practitioners during integration; thus a formal underpinning for schema restructuring has not yet been established. To establish a formal underpinning, one must extend current methodologies for schema integration to be able to express the equivalence of concepts that have nonidentical representations. Such expressive power is needed to be able to formally justify the correctness of the transformations that are used during schema restructuring. Our work addresses this problem by supporting more general forms of existence dependency constraints which allow the formal definition of the most common types of transformations that are required during schema restructuring. In this paper we formally define a decomposable normal form for schemas that specifies which properties a schema should have so that certain technical problem of concept merging do not occur. We also present an algorithm to transform a schema into an equivalent schema which is in decomposable normal form.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. [Bancilhon81]
    Bancilhon, F., Spyratos, N., “Update Semantics and Relational Views,” ACM Transactions on Database Systems, vol. 6, No. 4, Dec. 1981.Google Scholar
  2. [Batini84]
    Batini C., Lenzerini M., “A Methodology for Data Schema Integration in the Entity Relationship Model,” IEEE Trans. on Software Eng., SE-10(6):650–664, November 1984.Google Scholar
  3. [Chen76]
    Chen P. P., “The Entity-Relationship Model: Towards a Unified View of Data,” ACM Transaction on DAtabase Systems, 1, 1, 1976.Google Scholar
  4. [Codd 72]
    E. F. Codd, “Further Normalization of Data Base Relational Model,” in Data Base Systems, edited by Randell Rustin, Prentice Hall, 1972.Google Scholar
  5. [Cosmadakis84]
    Cosmadakis S. S., Papadimitriou C. H., “Updates of Relational Views,” J. ACM, Vol. 31, No. 4, Oct. 1984.Google Scholar
  6. [Dayal82]
    Dayal, U., Bernstein, P., “On the correct Translation of Update Operations on Relational Views,” ACM Transactions on Database Systems, vol. 7, No. 3, Sept. 1982.Google Scholar
  7. [Eick91]
    Eick, C. F., “A Methodology for the Design and Transformation of Conceptual Schemas,” Proceedings of 17th International Conference on Very Large Databases, Barcelona, Sept. 1991.Google Scholar
  8. [Hammer81]
    Hammer, M. and McLeod, D., “Database Description with SDM: A Semantic Database Model,” ACM TODS, vol. 6, no. 3, pp. 351–387, September 1981.Google Scholar
  9. [Jajodia83]
    Jajodia, S., Ng, P. A., Springsteel, “Entity-Relationship Diagrams which are in BCNF,” International Journal of Computer and Information Sciences 12,4 (1983).Google Scholar
  10. [Keller86]
    Keller, A.M., “The Role of Semantics in Translating View Updates,” IEEE Computer, vol. 19, no. 1, pp. 63–73, Jan. 1986.Google Scholar
  11. [Larson89]
    Larson, J. A., Navathe, S. B., Elmasri, R., “A Theory of Attribute Equivalence in Databases with Application to Schema Integration,” IEEE Transactions on Software Engineering, vol. 15, no. 4, April 1989.Google Scholar
  12. [Ling81]
    Ling, T. W., Tompa, F. W., Kameda, T., “An Improved Third Normal for Relational Databases,” ACM Transactions on Database Systems 6 2, June 1981.Google Scholar
  13. [Ling85]
    Ling, T. W., “A Normal Form For Entity-Relationship Diagrams,” Proceeding of the International Conference on Data Enginineering, pp. 24–35, 1985.Google Scholar
  14. [Miller93]
    Miller, R. J., Ioannidis, Y. E., Ramakrishman, R., “The Use of Information Capacity in Schema Integration and Translation,” Proceedings of 19th International Conference on Very Large Databases, Ireland, 1993.Google Scholar
  15. [Mylopoulos80]
    Mylopoulos, J., Bernstein, P. A., and Wong, H. K. T., “A Language Facility for Designing Database-Intensive Applications,” ACM Transactions on Database Systems, vol. 5, no. 2, pp. 185–207, June 1980.Google Scholar
  16. [Navathe86]
    Navathe, S. B., Elmasri, R., and Larson, J., “Integrating User Views in Database Design,” IEEE Computer, vol. 19, no. 1, pp. 50–62, Jan. 1986.Google Scholar
  17. [Rochfel92]
    Rochfeld, A., Negros, P., “Relationship of relationship and other interrelationship links in E-R model,” Data & Knowledge Engineering 9, Norh-Holland, 1992.Google Scholar
  18. [Spaccapietra]
    S., Parent, C.,“View Integration: A Step Forward in Solving Structural Conflicts,” IEEE Transaction on Knowledge and Data Engineering, vol. 6, no. 2, April 1994.Google Scholar
  19. [Shipman81]
    Shipman, D.W., “The Functional Data Model and the Data Language DAPLEX,” ACM TODS, vol. 6, no. 1, pp. 140–173, 1981.Google Scholar
  20. [Vidal94a]
    Vidal, V. M. P., Winslett, M., “Specifying View Update Translation in Schema Integration,” Third International Conference on Information and Knowledge Management (CIKM'94), Gaithersburg, 1994.Google Scholar
  21. [Vidal94b]
    Vidal, V. M. P., “Specifying View Update Translation in Schema Integration.” PhD Thesis, Department of Computer Science, Federal University of Rio de Janeiro, 1994.Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1995

Authors and Affiliations

  • Vânia M. P. Vidal
    • 1
  • Marianne Winslett
    • 2
  1. 1.Universidade Federal do CearáFortaleza, CearáBrazil
  2. 2.University of IllinoisUrbanaUSA

Personalised recommendations