A paradox in database theory

  • Stéphane Grumbach
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 646)

Abstract

In this paper, we prove that the larger the databases are, the lower the com-plexity of the evaluation of queries is. This work is based upon the asymptotic probabilities of the truth of properties and we focus on almost sure properties. We prove that for several undecidable properties of Datalog programs (which are important for the optimization), we can decide in polynomial space if they almost surely hold. Moreover, we show that these probabilistic properties can be used to define new optimization techniques. Finally, we study a concept of probabilistic definability, and see that it contrasts sharply with the logical definability. In particular, numerous results on the separation of languages with respect to their expressive power collapse for the probabilistic expressive power.

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Copyright information

© Springer-Verlag 1992

Authors and Affiliations

  • Stéphane Grumbach
    • 1
  1. 1.I.N.R.I.A.Le ChesnayFrance

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