Authors:
Jinghua Groppe
;
Sven Groppe
and
Jan Kolbaum
Affiliation:
University of Luebeck, Germany
Keyword(s):
Semantic Web, RDF, SPARQL, coreSPARQL, Query Optimization, Query Rewriting.
Related
Ontology
Subjects/Areas/Topics:
Databases and Information Systems Integration
;
Enterprise Information Systems
;
Web Databases
Abstract:
SPARQL is becoming an important query language for RDF data. Query optimization to speed up query processing has been an important research topic for all query languages. In order to optimize SPARQL queries, we suggest a core fragment of the SPARQL language, which we call the coreSPARQL language. coreSPARQL has the same expressive power as SPARQL, but eliminates redundant language constructs of SPARQL. SPARQL engines and optimization approaches will benefit from using coreSPARQL, because fewer cases need to be considered when processing coreSPARQL queries and the coreSPARQL syntax is machine-friendly. In this paper, we present an approach to automatically transforming SPARQL to coreSPARQL, and develop a set of rewriting rules to optimize coreSPRQL queries. Our experimental results show that our optimization of SPARQL speeds up RDF querying.