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Designing alpha-acyclic BCNF-database schemes

  • Detlev Ruland
  • Dietmar Seipel
Contributed Papers
Part of the Lecture Notes in Computer Science book series (LNCS, volume 305)

Abstract

The problem of designing database schemes satisfying the three design properties lossless join, Boyce-Codd normal form and α-acyclicity is considered. First, it is shown by a sample relation scheme, that these three properties are not always obtainable. This result is independent of any design method. Secondly, the problem of using the BCNF-decomposition algorithm for designing database schemes, which are additionally α-acyclic, is investigated. A characterization of those decomposotion processes yielding α-acyclic, lossless database schemes is given.

The main result of the paper is, that for each relation scheme an α-acyclic, lossless BCNF-database scheme can be constructed. This goal is reached by using the concept of lattice compatible augmentation, cf. /KaMa 80/, i.e. the original relation scheme is expanded by additional surrogate attributes (and related functional dependencies). Moreover, this result yields a modified two phase BCNF-decomposition algorithm.

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References

  1. /AuD'AtMos 84/.
    G. Ausiello, A. D'Atri, M. Moscarini: ‘Minimal Coverings of Acyclic Database Schemata', in ‘Advances in Database Theory, Vol. 2', ed.: H. Gallaire, J. Minker, J. Nicolas, Plenum Press, New York, 1984.Google Scholar
  2. /BeeFaMaiMeUlYa 81/.
    C. Beeri, R. Fagin, D. Maier, A. Mendelzon, J. Ullman, M. Yannakakis: ‘Properties of Acyclic Database Schemes', Proc. STOC 1981.Google Scholar
  3. /BeeFaMaiYa 83/.
    C. Beeri, R. Fagin, D. Maier, M. Yannakakis: ‘On the Desirability of Acyclic Database Schemes', JACM, vol. 30(3), 1983.Google Scholar
  4. /Be 76/.
    Ph. A. Bernstein: 'synthesizing Third Normal Form Relations From Functional Dependencies', ACM TODS, vol. 1(4), 1976.Google Scholar
  5. /Bi 85/.
    J. Biskup: ‘Entwurf von Datenbankschemas durch schrittweises Entfernen verbotener Teilstruckturen', Proc. GI-Conference ‘Entwurf von Informationssystemen', Tutzing, 1985.Google Scholar
  6. /BiBr 84/.
    J. Biskup, H. Brueggemann: ‘Towards Designing Acyclic Database Schemes', in: ‘Advances in Database Theory, Vol. 2', ed. H. Gallaire, J. Minker, J. M. Nicolas, Plenum Press, New York, 1984.Google Scholar
  7. /BiDaBe 79/.
    J. Biskup, U. Dayal, Ph. A. Bernstein: 'synthesizing Independent Relation Schemes', Proc. ACM SIGMOD 1979.Google Scholar
  8. /D'AtMos 84/.
    A. D'Atri, M. Moscarini: ‘On the Recognition and Design of Acyclic Databases', ACM Proc. PODS 1984.Google Scholar
  9. /Fa 83a/.
    R. Fagin: ‘Acyclic Database Schemes: A Painless Introduction', Proc. CAAP'83, LNCS 159, 1983.Google Scholar
  10. /Fa 83b/.
    R. Fagin: ‘Degrees of Acyclicity for Hypergraphs and Relational Database Systems', JACM, vol. 30(3), 1983.Google Scholar
  11. /KaMa 80/.
    P. Kandzia, M. Mangelmann: ‘On Covering Boyce-Codd Normal Forms', IPL, vol. 11(4,5), 1980.Google Scholar
  12. /Kat 84/.
    H. Katsuno: ‘An Extension of Conflict-Free Multivalued Dependency Sets', ACM TODS, vol.9(2), 1984.Google Scholar
  13. /Lie 82/.
    Y. E. Lien: ‘On the Equivalence of Database Models', JACM, vol. 29(2), 1982.Google Scholar
  14. /Mai 83/.
    D. Maier: ‘The Theory of Relational Databases', Computer Science Press, 1983.Google Scholar
  15. /Ru 85/.
    D. Ruland: ‘Modifications and Acyclic Decompositions of Relational Database Schemes', Ph.D. Thesis, 1985.Google Scholar
  16. /RuSei 86/.
    D. Ruland, D. Seipel: ‘Alpha-Acyclic Decompositions of Relational Database Schemes', ACM Proc. PODS 1986.Google Scholar
  17. /Sa 83/.
    D. Sacca: ‘On the Recognition of Coverings of Acyclic Database Hypergraphs', ACM Proc. PODS 1983.Google Scholar
  18. /Sa 85/.
    D. Sacca: ‘Closures of Database Hypergraphs', JACM, vol. 32(4), 1985.Google Scholar
  19. /Sei 85/.
    D. Seipel: ‘Entwurf azyklischer BCNF-Datenbankschemata', Diploma Thesis, 1985.Google Scholar
  20. /Ul 84/.
    J. D. Ullman: ‘Principles of Database Systems', Computer Science Press, 1984.Google Scholar
  21. /YuOz 86/.
    L.-Y. Yuan, Z. M. Ozsoyoglu: ‘Unifying Functional and Multivalued Dependencies for Relational Database Design', ACM Proc. PODS 1986.Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1988

Authors and Affiliations

  • Detlev Ruland
    • 1
  • Dietmar Seipel
    • 2
  1. 1.IBM Almaden Research CenterSan Jose
  2. 2.Lehrstuhl für Informatik IUniversity WürzburgWürzburgW.-Germany

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