Algebraic structures for capturing the provenance of SPARQL queriesAlgebraic structures for capturing the provenance of SPARQL queries
Faculty of Sciences. Mathematics and Computer Science
Advanced Database Research and Modeling (ADReM)
2016New York, N.Y., 2016
Journal of the Association for Computing Machinery. - New York, N.Y., 1954, currens
63(2016):1, p. 1-63
University of Antwerp
The evaluation of SPARQL algebra queries on various kinds of annotated RDF graphs can be seen as a particular case of the evaluation of these queries on RDF graphs annotated with elements of so-called spm-semirings. Spm-semirings extend semirings, used for representing the provenance of positive relational algebra queries on annotated relational data, with a new operator to capture the semantics of the non-monotone SPARQL operators. Furthermore, spm-semiring-based annotations ensure that desired SPARQL query equivalences hold when querying annotated RDF. In this work, in addition to introducing spm-semirings, we study their properties and provide an alternative characterization of these structures in terms of semirings with an embedded boolean algebra (or seba-structure for short). This characterization allows us to construct spm-semirings and identify a universal object in the class of spm-semirings. Finally, we show that this universal object provides a provenance representation of poly-sized overhead and can be used to evaluate SPARQL queries on arbitrary spm-semiring-annotated RDF graphs.