RDF Reification Benchmark (REF) using the Biomedical Knowledge Repository (BKR)

This resource can be used for benchmarking different RDF modelling solutions for statement-level metadata, namely:  - RDF Reification, - Singleton Property, - RDF (RDF-star).    More details about this resource can be found in the following publication: Fabrizio Orlandi, Damien Graux, Declan O'Sullivan, "Benchmarking RDF Metadata Representations: Reification, Singleton Property and RDF", 15th IEEE International Conference on Semantic Computing (ICSC), 2021. Pre-print available at: http://fabriziorlandi.net/pdf/2021/ICSC2021_REF-Benchmark.pdf   The dataset contains 3 different versions of the Biomedical Knowledge Repository (BKR) knowledge graph, as described in: Vinh Nguyen, Olivier Bodenreider, Amit Sheth. "Don't Like RDF Reification? Making Statements About Statements Using Singleton Property" WWW 2014, doi: 10.1145/2566486.2567973. and, Satya S. Sahoo, Olivier Bodenreider, Pascal Hitzler, Amit Sheth and Krishnaprasad Thirunarayan. "Provenance Context Entity (PaCE): Scalable Provenance Tracking for Scientific RDF Data" in Sci Stat Database Manag. 2010; 6187: 461–470. doi: 10.1007/978-3-642-13818-8_32   The 3 knowledge graphs dumps are packaged as Gzipped RDF files in Turtle (and Turtle) syntax.  BKR-R-fullKGdump.ttl.gz for the Reification method, BKR-S-fullKGdump.ttl.gz for the Singleton method, BKR-star-fullKGdump.ttls.gz for the RDF (RDF-star) method.   The RDF REiFication Benchmark (REF) includes also a set of SPARQL (and SPARQL) queries that can be used to compare the performance of different triplestores. Details about the SPARQL queries, and the queries themselves, are included in the "REF-Benchmark.tar.gz" archive. The queries are named after the dataset they are designed for (BKR-R or BKR-S or BKR-star), plus they include a letter identifying the query set, and a query number.  E.g. the query in the file "BKR-R_F-Q3.rq" is for the BKR-R (standard reification) dataset, it is part of the query set "F" and it is the number 3 of that set "F". Hence, the same query, but translated for the RDF dataset in SPARQL syntax, is contained in "BKR-star_F-Q3.rq". Sets "A" and "B" are derived from the queries introduced by V. Nguyen et al. in: "Don't Like RDF Reification? Making Statements About Statements Using Singleton Property" WWW 2014, doi: 10.1145/2566486.2567973. Set "F" has been designed more with RDF in mind as part of this benchmark (see [Orlandi et al., ICSC 2021])