While the task of answering queries from an arbitrary propositional theory is intractable in general, it can typicallybe performed e ciently if the theory is Horn. This suggests t...
The integration of database and programming languages is made difficult by the different data models and type systems prevalent in each field. Functional-object query languages con...
We present an optimization method and algorithm designed for three objectives: physical data independence, semantic optimization, and generalized tableau minimization. The method ...
Databases may not satisfy integrity constraints (ICs) for several reasons. Nevertheless, in most of the cases an important part of the data is still consistent wrt certain desired...
In this work, we present a semantic query optimization technique to improve the efficiency of the evaluation of a subset of SQL:1999 recursive queries. Using datalog notation, we c...