A Probabilistic NF2 Relational Algebra for Imprecision in Databases
نویسنده
چکیده
We present a probabilistic data model which is based on relations in non-rst-normal-form (NF2). Here, tuples are assigned probabilistic weights giving the probability that a tuple belongs to a relation. This way, imprecise attribute values are modelled as a probabilistic subrelation. For information retrieval, the set of weighted index terms of a document can be represented in the same way, thus supporting the integration of information retrieval and database systems. By redeening the relational operators for this type of relations, the result of each operator is again a probabilistic NF2 relation, where the weight of a tuple gives the probability that this tuple belongs to the result.
منابع مشابه
A Probabilistic NF2 Relational Algebra for Integrated Information Retrieval and Database Systems
The integration of information retrieval (IR) and database systems requires a data model which allows for modelling documents as entities, representing uncertainty and vagueness and performing uncertain inference. For this purpose, we present a probabilistic data model based on relations in non-rst-normal-form (NF2). Here, tuples are assigned probabilistic weights giving the probability that a ...
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