Selectivity Estimation for SPARQL Triple Patterns with Shape Expressions [chapter]

Abdullah Abbas, Pierre Genevès, Cécile Roisin, Nabil Layaïda
2018 Lecture Notes in Computer Science  
ShEx (Shape Expressions) is a language for expressing constraints on RDF graphs. In this work we optimize the evaluation of conjunctive SPARQL queries, on RDF graphs, by taking advantage of ShEx constraints. Our optimization is based on computing and assigning ranks to query triple patterns, dictating their order of execution. We first define a set of well formed ShEx schemas, that possess interesting characteristics for SPARQL query optimization. We then define our optimization method by
more » ... ting information extracted from a ShEx schema. We finally report on evaluation results performed showing the advantages of applying our optimization on the top of an existing state-of-the-art query evaluation system.
doi:10.1007/978-3-319-91662-0_15 fatcat:tnpep777vbbvfcgqnsofpid2dm