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 creating standardised 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.Comment: ADBIS conference (21st European Conference on Advances in Databases
and Information Systems) The final publication is available at Springer via
https://doi.org/10.1007/978-3-319-66917-5_1
