Urn Models and Yao’s Formula

  • Danièle Gardy
  • Laurent Némirovski
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 1540)


Yao’s formula is one of the basic tools in any situation where one wants to estimate the number of blocks to be read in answer to some query. We show that such situations can be modelized by probabilistic urn models. This allows us to fully characterize the distribution probability of the number of selected blocks under uniformity assumptions, and to consider extensions to non-uniform block probabilities. We also obtain a computationnally effcient approximation of Yao’s formula.


Asymptotic Formula Exact Formula High Order Moment Uniformity Assumption Cient Approximation 
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Copyright information

© Springer-Verlag Berlin Heidelberg 1999

Authors and Affiliations

  • Danièle Gardy
    • 1
  • Laurent Némirovski
    • 1
  1. 1.Laboratoire PRiSMUniversité de Versailles Saint-QuentinVersaillesFrance

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