About Ill-Known Data and Equi-Join Operations

  • Patrick Bosc
  • Ludovic Liétard
  • Olivier Pivert
Conference paper
Part of the Advances in Soft Computing book series (AINSC, volume 7)


In this paper, we are concerned with the querying of databases that may contain ill-known attribute values represented by possibility distributions. While the operations of selection and projection can be straightforwardly extended in such a context, this is not the case for the equi-join operator for which several semantics are possible. These different semantics are pointed out, as well as the corresponding situations in terms of information need. The issue of query compositionality is also examined in each case.


Possibility Distribution Possibility Theory Linguistic Label Possibility Degree Selection Query 
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Copyright information

© Springer-Verlag Berlin Heidelberg 2001

Authors and Affiliations

  • Patrick Bosc
    • 1
  • Ludovic Liétard
    • 2
  • Olivier Pivert
    • 1
  1. 1.IRISA/ENSSATTechnopole AnticipaLannion CedexFrance
  2. 2.IRISA/IUTTechnopole AnticipaLannion CedexFrance

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