Extending Fagin’s Algorithm for More Users Based on Multidimensional B-Tree

  • Matúš Ondreička
  • Jaroslav Pokorný
Part of the Lecture Notes in Computer Science book series (LNCS, volume 5207)


We discuss the issue of searching the best K objects in more attributes for more users. Every user prefers objects in different ways. User preferences are modelled locally with a fuzzy function and globally with an aggregation function. Also, we discuss the issue of searching the best K objects without accessing all objects. We deal with the use of local preferences when computing Fagin’s algorithms. We created a new model of lists for Fagin’s algorithms based on B + -trees. Furthermore, we use a multidimensional B-tree (MDB-tree)for searching the best K objects. We developed an MD-algorithm, which can effectively find the best K objects in a MDB-tree in accordance with user’s preferences and without accessing all the objects. We show that MD-algorithm achieves better results in the number of accessed objects than Fagin’s algorithms.


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Copyright information

© Springer-Verlag Berlin Heidelberg 2008

Authors and Affiliations

  • Matúš Ondreička
    • 1
  • Jaroslav Pokorný
    • 1
  1. 1.Faculty of Mathematics and PhysicsCharles UniversityPrague

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