no code implementations • 9 Apr 2021 • Sihem Amer-Yahia, Georgia Koutrika, Frederic Bastian, Theofilos Belmpas, Martin Braschler, Ursin Brunner, Diego Calvanese, Maximilian Fabricius, Orest Gkini, Catherine Kosten, Davide Lanti, Antonis Litke, Hendrik Lücke-Tieke, Francesco Alessandro Massucci, Tarcisio Mendes de Farias, Alessandro Mosca, Francesco Multari, Nikolaos Papadakis, Dimitris Papadopoulos, Yogendra Patil, Aurélien Personnaz, Guillem Rull, Ana Sima, Ellery Smith, Dimitrios Skoutas, Srividya Subramanian, Guohui Xiao, Kurt Stockinger
We demonstrate that our system is uniquely accessible to a wide range of users from larger scientific communities to the public.
no code implementations • 3 Dec 2020 • Diego Calvanese, Avigdor Gal, Davide Lanti, Marco Montali, Alessandro Mosca, Roee Shraga
Virtual Knowledge Graphs (VKG) constitute one of the most promising paradigms for integrating and accessing legacy data sources.
no code implementations • 12 May 2020 • Diego Calvanese, Julien Corman, Davide Lanti, Simon Razniewski
Counting answers to a query is an operation supported by virtually all database management systems.
no code implementations • 1 Jun 2019 • Diego Calvanese, Davide Lanti, Ana Ozaki, Rafael Penaloza, Guohui Xiao
In particular, we investigate the problems of (i) deciding whether a provenance annotated OBDA instance entails a provenance annotated conjunctive query, and (ii) computing a polynomial representing the provenance of a query entailed by a provenance annotated OBDA instance.
1 code implementation • 21 Jul 2016 • Davide Lanti, Guohui Xiao, Diego Calvanese
The advantage of the approach is that the user is not required to manually input the characteristics of the data to be produced, making it particularly suitable for OBDA benchmarks, where the complexity of database schemas might pose a challenge for manual input (e. g., the NPD benchmark contains 70 tables with some containing more than 60 columns).
Databases
no code implementations • 13 May 2016 • Dag Hovland, Davide Lanti, Martin Rezk, Guohui Xiao
In Ontology Based Data Access (OBDA) users pose SPARQL queries over an ontology that lies on top of relational datasources.