Hypergraph based query optimization

Resource Description Framework (RDF) is the fundamental data model for storing information on the web. In recent years, the amount of RDF data available on the web is increasing rapidly. As RDF is a graph based data model, the evaluation of SPARQL queries become expensive. Query optimization and data management problems are the key challenges associated with RDF data. This paper is focused on the concept of hypergraph for storing RDF data and graph based index for query processing. We propose some algorithms for transformation of RDF graph to hypergraph, formation of index, generating query path and for query processing. A PredicateBasedIndex (PBI) is created, from RDF graph, with the help of the size of hyper-edges. According to this index a query path is built for a SPARQL query and executed on the hypergraph. These algorithms are analyzed and compared with some existing literature based on query optimization.