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Link Traversal Query Processing Over Decentralized Environments with Structural Assumptions

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The Semantic Web – ISWC 2023 (ISWC 2023)

Part of the book series: Lecture Notes in Computer Science ((LNCS,volume 14265))

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Abstract

To counter societal and economic problems caused by data silos on the Web, efforts such as Solid strive to reclaim private data by storing it in permissioned documents over a large number of personal vaults across the Web. Building applications on top of such a decentralized Knowledge Graph involves significant technical challenges: centralized aggregation prior to query processing is impossible for legal reasons, and current federated querying techniques cannot handle this large scale of distribution at the expected performance. We propose an extension to Link Traversal Query Processing (LTQP) that incorporates structural properties within decentralized environments to tackle their unprecedented scale. In this article, we analyze the structural properties of the Solid decentralization ecosystem that are relevant for query execution, we introduce novel LTQP algorithms leveraging these structural properties, and evaluate their effectiveness. Our experiments indicate that these new algorithms obtain correct results in the order of seconds, which existing algorithms cannot achieve. This work reveals that a traversal-based querying method using structural assumptions can be effective for large-scale decentralization, but that advances are needed in the area of query planning for LTQP to handle more complex queries. These insights open the door to query-driven decentralized applications, in which declarative queries shield developers from the inherent complexity of a decentralized landscape.

Canonical version: https://comunica.github.io/Article-ISWC2023-SolidQuery/

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Acknowledgements

This work is supported by SolidLab Vlaanderen (Flemish Government, EWI and RRF project VV023/10). Ruben Taelman is a postdoctoral fellow of the Research Foundation – Flanders (FWO) (1274521N).

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Authors and Affiliations

  1. IDLab, Department of Electronics and Information Systems, Ghent University – imec, Ghent, Belgium

    Ruben Taelman & Ruben Verborgh

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  1. Ruben Taelman
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  2. Ruben Verborgh
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Correspondence to Ruben Taelman .

Editor information

Editors and Affiliations

  1. University of Liverpool, Liverpool, UK

    Terry R. Payne

  2. University of Bologna, Bologna, Italy

    Valentina Presutti

  3. Southeast University, Nanjing, China

    Guilin Qi

  4. Universidad Politécnica de Madrid, Madrid, Spain

    María Poveda-Villalón

  5. Huawei Technologies R&D UK, Edinburgh, UK

    Giorgos Stoilos

  6. Centrum Wiskunde and Informatica, Amsterdam, The Netherlands

    Laura Hollink

  7. IT University of Copenhagen, Copenhagen, Denmark

    Zoi Kaoudi

  8. Nanjing University, Nanjing, China

    Gong Cheng

  9. Tsinghua University, Beijing, Beijing, China

    Juanzi Li

Supplemental Material Statement

Supplemental Material Statement

Implementation: https://github.com/comunica/comunica-feature-link-traversal Experiments: https://github.com/comunica/Experiments-Solid-Link-Traversal Benchmark: https://github.com/SolidBench/SolidBench.js.

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Taelman, R., Verborgh, R. (2023). Link Traversal Query Processing Over Decentralized Environments with Structural Assumptions. In: Payne, T.R., et al. The Semantic Web – ISWC 2023. ISWC 2023. Lecture Notes in Computer Science, vol 14265. Springer, Cham. https://doi.org/10.1007/978-3-031-47240-4_1

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  • DOI: https://doi.org/10.1007/978-3-031-47240-4_1

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