Description and identification of distributed fragments of recursive relations

In a distributed environment, it is advantageous to fragment a relation and store the fragments at various sites. Based on the concept of lattice structures, we develop a framework to study the fragmentation problems of distributed recursive relations. Two of the fragmentation problems are how to describe and identify fragments. Description and identification methods previously suggested are more suitable in parallel environments than in distributed databases. We propose a method to describe and identify fragments based on lattice structures. Finding lattice descriptions of fragments is shown to be an NP complete problem. We analyze the performance of the lattice approach both theoretically and experimentally. This is done by creating a database of recursive relations. The empirical analysis shows that our proposed algorithms give near optimal solutions.