4 research outputs found
A fast algorithm for query optimization in Universal Relation databases
AbstractThe method of the canonical connection introduced by Maier and Ullman provides an optimal procedure for query processing in universal-relation databases. We present an algorithm for computing canonical connections in a database scheme which is more efficient than the classical algorithm based on tableau reduction. Moreover, with a slight modification of the algorithm we obtain a join plan which succeeds in controlling the nonmonotonicity of cyclic canonical connections