Matrix "Bit" loaded: a scalable lightweight join query processor for RDF data

The Semantic Web community, until now, has used traditional database systems for the storage and querying of RDF data. The SPARQL query language also closely follows SQL syntax. As a natural consequence, most of the SPARQL query processing techniques are based on database query processing and optimization techniques. For SPARQL join query optimization, previous works like RDF-3X and Hexastore have proposed to use 6-way indexes on the RDF data. Although these indexes speed up merge-joins by orders of magnitude, for complex join queries generating large intermediate join results, the scalability of the query processor still remains a challenge. In this paper, we introduce (i) BitMat – a compressed bit-matrix structure for storing huge RDF graphs, and (ii) a novel, light-weight SPARQL join query processing method that employs an initial pruning technique, followed by a variable-binding-matching algorithm on BitMats to produce the final results. Our query processing method does not bui...

• Type: Conference
• Year: 2010
• Where: WWW
• Authors: Medha Atre, Vineet Chaoji, Mohammed J. Zaki, James A. Hendler
• Keywords: Internet Technology, Query Processing, SPARQL Join Query, SPARQL Query, WWW 2010