Algebra representation and transformation for SPARQL query
Zhuang Miao · Computer Engineering and Applications Journal · 2011
This paper focuses on the query transforming problem in ontology-based data integration systems.An algebrabased approach for SPARQL query representation and transformation is proposed.The relational algebra for RDF graph pattern is introduced.Five algebraic operators:UNION,DIFFERENCE,PRODUCT,SELECT and PROJECT are defined.A relational representation of SPARQL query is presented.The semantic equivalence of this relational representation is further discussed.A query transforming approach is presented to implement the query transformation from SPARQL query to SQL query plans that can be executed on relational databases.Results show that this approach can solve the query transformation problem effectively.