New transitive closure algorithm for recursive query processing in deductive databases

Abstract

An algorithm suitable for the full transitive closure problem, which is used to solve uninstantiated recursive queries in deductive databases, is presented. In this algorithm there are two phases. In the first phase a general graph is condensed into an acyclic graph and at the same time a special sparse matrix is formed from the acyclic graph. The second phase is the main one, where all of the page I/O operations are minimized. Simulation is used to study the performance of this algorithm and compare it with that of previous algorithms.<>