5 papers
PathDB: A system for evaluating regular path queries
Roberto GarcÃa, Renzo Angles, Vicente Rojas +1
Regular Path Queries (RPQs) are a core mechanism for expressing recursion and reachability in graph databases. However, most systems evaluate RPQs with traversal-based algorithms t…
From Embedded Properties to Trait Nodes: A Design Method for Identifying Reusable Metadata in Property Graph Schemas
Yahya Sa'd, Renzo Angles, Vojtech Merunka +3
Property-graph schemas often contain descriptive properties that recur across heterogeneous nodes and edges, yet schema designers lack a clear method for deciding whether such prop…
Multiset semantics in SPARQL, Relational Algebra and Datalog
Renzo Angles, Claudio Gutierrez, Daniel Hernández
The paper analyzes and characterizes the algebraic and logical structure of the multiset semantics for SPARQL patterns involving AND, UNION, FILTER, EXCEPT, and SELECT. To do this,…
The Fifth Graph Normal Form (5GNF): A Trait-Based Framework for Metadata Normalization in Property Graphs
Yahya Sa'd, Vojtech Merunka, Renzo Angles
Graph databases are widely used in systems that manage rich metadata, yet current modelling practices often embed descriptive attributes directly in nodes, leading to redundancy an…
Properties for Paths in Graph Databases
Fernando Orejas, Elvira Pino, Renzo Angles +2
This paper presents a formalism for defining properties of paths in graph databases, which can be used to restrict the number of solutions to navigational queries. In particular, o…