An Eecient Uniication Algorithm for a Logic Database Language for Nested Relations

Although eecient uniication algorithms exist for logic database queries for at relations , no eecient uniication algorithm has been proposed for logic database queries for nested relations. As a result, the required time to process logic database queries for nested relations is often less than ideal. To overcome this shortcoming, we propose here a linear time uniication algorithm for a large class of logic database queries for nested relations. The algorithm provides an eecient evaluation technique for many common nested relational queries. Our paper includes a characterization of the class of nested relational queries that can be handled by our proposed linear time uniication algorithm and also the proof of the linearity of the algorithm.