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An almost linear time algorithm for computing a dependency basis in a relational data base

  • Zvi Galil
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 85)

Abstract

We describe an algorithm that constructs for a given set of (functional and multivalued) dependencies Σ and a set of attributes X, the dependency basis of X. The algorithm runs in time O(min(k,log p)|Σ|), where p is the number of sets in the dependency basis of X and k is the number of dependencies in Σ. A variant of the algorithm tests whether a dependency σ is implied by Σ in time O(min(k,log p) |Σ|), where p is the number of sets in the dependency basis of the left-hand side of σ that intersect the right-hand side of σ. Whenever all the dependencies in ΣU{σ} are functional dependencies these algorithms are linear time.

Keywords

Relational Database Functional Dependency Propositional Logic Linear Time Algorithm Correctness Proof 
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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References

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Copyright information

© Springer-Verlag Berlin Heidelberg 1980

Authors and Affiliations

  • Zvi Galil
    • 1
  1. 1.Department of Mathematical Sciences Computer Science DivisionTel Aviv UniversityTel AvivIsrael

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