Efficient Query Subscription Processing in a Broadcast Environment

This paper introduces techniques for reducing data dissemination costs of query subscriptions.This is achieved by merging queries with overlapping, but not necessarily equal, answers.The paper formalizes the query merging problem and introduces a general cost model for it.We prove that the problem is NP-hard and propose exhaustive algorithms and three heuristicalgorithms: the Pair Merging Algorithm, the Directed Search Algorithm and the ClusteringAlgorithm. We develop a simulator for...