Advertisement

On the uniqueness of nested relations

  • Koichi Takeda
Part II Fundamental Issues
Part of the Lecture Notes in Computer Science book series (LNCS, volume 361)

Abstract

In this paper, we consider two fundamental properties of nested relations: minimum and uniqueness. By nested relations we mean relations over simple and/or set-valued domains. It is shown that the complexity of deciding whether or not a given first normal form relation has a nested form with no more than K tuples is NP-complete. A template dependency is given as an essential integrity constraint to guarantee that a class of first normal form relations has unique nested relations with minimum number of tuples.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. [1]
    H. Arisawa, K. Moriya, and T. Miura. “Operations and the Properties on Non-First-Normal-Form Relational Databases”. In Proc. of the 9th International Conference on Very Large Data Bases, pages 197–204, October 1983.Google Scholar
  2. [2]
    F. Bancilhon, P. Richard, and M. Scholl. “On Line Processing of Compacted Relations”. In Proc. of the 8th International Conference on Very Large Data Bases, pages 263–269, September 1982.Google Scholar
  3. [3]
    P. Dadam, K. Kuespert, F. Andersen, H. Blanken, R. Erbe, J. Guenauer, V. Lum, P. Pistor, and G. Walch. “A DBMS Prototype to Support Extended NF2 Relations: An Integrated View of Flat Tables and Hierarchies”. In Proc. of the ACM SIGMOD International Conference on Management of Data, pages 356–366, August 1986.Google Scholar
  4. [4]
    R. Fagin, D. Maier, J. D. Ullman, and M. Yannakakis. “Tools for Template Dependencies”. SIAM Journal on Computing, 12(1):36–59, February 1983.Google Scholar
  5. [5]
    P. C. Fischer, L. V. Saxton, S. J. Thomas, and D. Van Gucht. “Interactions between Dependencies and Nested Relational Structures”. Journal of Computer and System Sciences, 31(3):343–354, December 1985.Google Scholar
  6. [6]
    P. C. Fischer and D. Van Gucht. “Determining When a Structure is a Nested Relation”. In Proc. of the 11th International Conference on Very Large Data Bases, pages 171–180, August 1985.Google Scholar
  7. [7]
    P. C. Fischer and D. Van Gucht. “Weak Multivalued Dependencies”. In Proc. of the 3rd ACM SIGACT-SIGMOD Symposium on Principles of Database Systems, pages 266–274, April 1984.Google Scholar
  8. [8]
    M. R. Garey and D. S. Johnson. Computers and Intractability: A Guide to the Theory of NP-Completeness. Freeman, San Francisco, CA., 1979.Google Scholar
  9. [9]
    G. Jaeschke and H.-J. Schek. “Remarks on the Algebra of Non First Normal Form Relations”. In Proc. of the 1st ACM SIGACT-SIGMOD Symposium on Principles of Database Systems, pages 124–138, March 1982.Google Scholar
  10. [10]
    Y. Kambayashi, K. Tanaka, and K. Takeda. “Synthesis of Unnormalized Relations Incorporating More Meaning”. International Journal of Information Sciences, 29(2–3):201–247, May–June 1983.Google Scholar
  11. [11]
    D. Maier. The Theory of Relational Databases. Computer Science Press, Rockville, MD., 1983.Google Scholar
  12. [12]
    D. Maier, A. O. Mendelzon, and Y. Sagiv. “Testing Implications of Data Dependencies”. ACM Transactions on Database Systems, 455–469, December 1979.Google Scholar
  13. [13]
    A. Makinouchi. “A Consideration on Normal Form of Not-Necessarily-Normalized Relation in the Relational Data Model”. In Proc. of the 3rd International Conference on Very Large Data Bases, pages 447–453, October 1977.Google Scholar
  14. [14]
    W. Marek and M. Truszczynski. “NF2 database and rule-based expert systems”. In Workshop Material: Theory and Applications of Nested Relations and Complex Objects, pages 86–88, 1987.Google Scholar
  15. [15]
    Z. M. Ozsoyoglu and L.-Y. Yuan. “A New Normal Form for Nested Relations”. ACM Transactions on Database Systems, 12(1):111–136, March 1987.Google Scholar
  16. [16]
    M. A. Roth. “New Design Methods for non-1NF Relational Databases”. In Workshop Material: Theory and Applications of Nested Relations and Complex Objects, pages 101–104, 1987.Google Scholar
  17. [17]
    F. Sadri and J. D. Ullman. “Template Dependencies: a Large Class of Dependencies in Relational Databases and its Complete Aximatization”. Journal of the ACM, 28(3):435–453, July 1981.Google Scholar
  18. [18]
    M. H. Scholl and H.-J. Schek, editors. Theory and Applications of Nested Relations and Complex Objects: An International Workshop, Technical University of Darmstadt, Institut National de Recherche en Informatique et en Automatique, April 1987.Google Scholar
  19. [19]
    J. D. Ullman. Principles of Database Systems. Computer Science Press, Rockville, MD., second edition, 1982.Google Scholar
  20. [20]
    D. Van Gucht and P. C. Fischer. “Some Classes of Multilevel Relational Structures”. In Proc. of the 5th ACM SIGACT-SIGMOD Symposium on Principles of Database Systems, pages 60–69, March 1986.Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1989

Authors and Affiliations

  • Koichi Takeda
    • 1
  1. 1.Tokyo Research Laboratory, IBM Japan, Ltd.TokyoJapan

Personalised recommendations