Identifying, Querying, and Relating Large Heterogeneous RDF Sources

Tracking #: 2457-3671

This paper is currently under review
Andre Valdestilhas
Tommaso Soru2
Muhammad Saleem
Edgard Marx1
Wouter Beek1
Claus Stadler
Bernardo Pereira Nunes1
Konrad Höffner
Thomas Riechert

Responsible editor: 
Ruben Verborgh

Submission type: 
Full Paper
Although we have witnessed the growing adoption of Linked Open Data principles for publishing data on the Web, connecting data to third parties remains a difficult and time-consuming task. One question that often arises during the publication process is: ``Is there any data set available on the Web we can connect with?". This simple question unfolds a set of others that hinders data publishers to connect to other data sources. For instance, if there are related data sets, where are they? How many? Do they share concepts and properties? How similar are they? Is there any duplicated data set? How to identify and query a huge amount of heterogeneous datasets. To answer these questions, this paper introduces: (i) a new class of data repositories; (ii) a method to identify datasets containing a given URI; (iii) a query engine and source selection in a large RDF dataset collection; (iv) a novel method to detect and store data set similarities including duplicated data set and data set chunk detection; (v) an index to store data set relatedness; and, (vi) a search engine to find related data sets. To create the index, we harvested more than 668k data sets from LOD Stats and LOD Laundromat, along with 559 active SPARQL endpoints corresponding to 221.7 billion triples or 5 terabytes of data. Our evaluation on state-of-the-art real-data shows that more than 90% of data sets in the LOD Laundromat do not use owl:equivalentProperty or owl:equivalentClass to relate to one another data, which reaffirms and emphasizes the importance of our work.
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