Rewriting queries on SPARQL views

The problem of answering SPARQL queries over virtual SPARQL views is commonly encountered in a number of settings, including while enforcing security policies to access RDF data, or when integrating RDF data from disparate sources. We approach this problem by rewriting SPARQL queries over the views to equivalent queries over the underlying RDF data, thus avoiding the costs entailed by view materialization and maintenance. We show that SPARQL query rewriting combines the most challenging aspects of rewriting for the relational and XML cases: like the relational case, SPARQL query rewriting requires synthesizing multiple views; like the XML case, the size of the rewritten query is exponential to the size of the query and the views. In this paper, we present the first native query rewriting algorithm for SPARQL. For an input SPARQL query over a set of virtual SPARQL views, the rewritten query resembles a union of conjunctive queries and can be of exponential size. We propose optimizatio...

• Type: Journal
• Year: 2011
• Where: WWW
• Authors: Wangchao Le, Songyun Duan, Anastasios Kementsietsidis, Feifei Li, Min Wang
• Keywords: Basic Rewriting Algorithm, Internet Technology, RDF Data, Sparql, WWW 2011