Null Values Revisited in Prospect of Data Integration

  title={Null Values Revisited in Prospect of Data Integration},
  author={Guy De Tr{\'e} and Rita M. M. De Caluwe and Henri Prade},
  booktitle={International Conference on Semantics of a Networked World},
A considerable part of the information available in the real world is inherently imperfect and/or incomplete. Traditionally, the most commonly adopted modelling approaches for dealing with imperfect and missing information are based on the use of default values and of null values. However, in order to deal with imperfect information in a more efficient way, a database system needs some more advanced modelling facilities that better reflect the semantics of the data. Such facilities become even… 

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