Modeling uncertainty in databases
Fereidoon Sadri · 2002
Relational algebra operations were extended to produce, together with answers to queries, information regarding sources that contributed to the answers. The author's previous model is reviewed and the semantic interpretation is presented. It is shown that extended relational algebra operations are precise, that is, they produce exactly the same answers that are expected under the semantic interpretation. Algorithms for computing the reliability of answers to a query are also reviewed and their correctness under the semantic interpretation proposed is proved.>