Scalar Aggregation in FD-Inconsistent Databases

  • Marcelo Arenas
  • Leopoldo Bertossi
  • Jan Chomicki
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 1973)


We consider here scalar aggregation queries in databases that may violate a given set of functional dependencies. We show how to compute consistent answers (answers true in every minimal repair of the database) to such queries. We provide a complete characterization of the computational complexity of this problem. We also show how tractability can be obtained in several special cases (one involves a novel application of the perfect graph theory) and present a practical hybrid query evaluation method.


Maximum Clique Integrity Constraint Perfect Graph Database Instance Consistent Answer 
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Copyright information

© Springer-Verlag Berlin Heidelberg 2001

Authors and Affiliations

  • Marcelo Arenas
    • 1
  • Leopoldo Bertossi
    • 2
  • Jan Chomicki
    • 3
  1. 1.Department of Computer ScienceUniversity of Toronto
  2. 2.Escuela de Ingeniería, Departamento de Ciencia de ComputacionPontificia Universidad Catolica de ChileChile
  3. 3.Department of Computer Science and EngineeringUniversity at BuffaloUSA

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