Authors: Julien Aimonier-Davat, Minh-Hoang Dang, Pascal Molli, Brice Nédelec, and Hala Skaf-Molli
Sampling-based Approximate Query Processing (S-AQP) has many important use cases for RDF, including computing large-scale statistics, embeddings, join orderings, approximate aggregations, summaries, and exploratory queries. However, current SPARQL endpoints have no support for S-AQP, and many queries just time out on public SPARQL endpoints. In this demonstration, we present RAW-Jena: an extension of Apache Jena to support S-AQP for conjunctive SPARQL queries relying on random walks. RAW-Jena delivers partial random results and cardinality estimates in a pay-as-you-go fashion.
This work is supported by the French ANR project DeKaloG (Decentralized Knowledge Graphs) ANR-19-CE23-0014, and the French Labex CominLabs project MiKroloG (The Microdata Knowledge Graph).