Aggregate Operations in the Information Source Tracking Method
The Information Source Tracking method, IST, is an approach to the management of uncertain and imprecise data in database systems. In this paper we study the processing of queries involving aggregate operations in the IST method. The problems discussed include producing all possible outcomes of an aggregate query and their probabilities, and determining the probability of a specific outcome. We present algorithms for the evaluation of aggregate queries, and show that some of these problems are intractable.
KeywordsInformation Source Query Processing Truth Assignment Disjunctive Normal Form Extended Relation
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