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Formalising openCypher Graph Queries in Relational Algebra

  • József Marton
  • Gábor Szárnyas
  • Dániel Varró
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 10509)

Abstract

Graph database systems are increasingly adapted for storing and processing heterogeneous network-like datasets. However, due to the novelty of such systems, no standard data model or query language has yet emerged. Consequently, migrating datasets or applications even between related technologies often requires a large amount of manual work or ad-hoc solutions, thus subjecting the users to the possibility of vendor lock-in. To avoid this threat, vendors are working on supporting existing standard languages (e.g. SQL) or standardising languages.

In this paper, we present a formal specification for openCypher, a high-level declarative graph query language with an ongoing standardisation effort. We introduce relational graph algebra, which extends relational operators by adapting graph-specific operators and define a mapping from core openCypher constructs to this algebra. We propose an algorithm that allows systematic compilation of openCypher queries.

Notes

Acknowledgements

Gábor Szárnyas and Dániel Varró were supported by the MTA-BME Lendület Research Group on Cyber-Physical Systems and the NSERC RGPIN-04573-16 project. The authors would like to thank Gábor Bergmann and János Maginecz for their comments on the draft of this paper.

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Copyright information

© Springer International Publishing AG 2017

Authors and Affiliations

  • József Marton
    • 1
  • Gábor Szárnyas
    • 2
    • 3
  • Dániel Varró
    • 2
    • 3
  1. 1.Database LaboratoryBudapest University of Technology and EconomicsBudapestHungary
  2. 2.Fault Tolerant Systems Research Group, MTA-BME Lendület Research Group on Cyber-Physical SystemsBudapest University of Technology and EconomicsBudapestHungary
  3. 3.Department of Electrical and Computer EngineeringMcGill UniversityMontrealCanada

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