Graph databases have gained renewed interest in the last years, due to its applications in
areas such as the Semantic Web and Social Networks Analysis. We study the problem of …

Graph databases have received much attention as of late due to numerous applications in
which data is naturally viewed as a graph; these include social networks, RDF and the …

Graph data management concerns the research and development of powerful technologies
for storing, processing and analyzing large volumes of graph data. This chapter presents an …

Graph databases are currently one of the most popular paradigms for storing data. One of
the key conceptual differences between graph and relational databases is the focus on …

With the proliferation of knowledge graphs, massive RDF graphs have been published on
the Web. As an essential type of queries for RDF graphs, Regular Path Queries (RPQs) have …

The World Wide Web Consortium (W3C) recently introduced property paths in SPARQL 1.1,
a query language for RDF data. Property paths allow SPARQL queries to evaluate regular …

Querying RDF data is viewed as one of the main applications of graph query languages,
and yet the standard model of graph databases--essentially labeled graphs--is different from …

Motivated by both established and new applications, we study navigational query languages
for graphs (binary relations). The simplest language has only the two operators union and …

It is known that unions of acyclic conjunctive queries (CQs) can be evaluated in linear time,
as opposed to arbitrary CQs, for which the evaluation problem is NP-complete. It follows …

The industry-wide adoption of graph databases has been hindered due to the fragmentation
in syntax and semantics of available graph query languages. As a result, several projects …