157 citations · 284 across the 16 of their papers we have counts for
18 papers
PG-Schema: Schemas for Property Graphs
Renzo Angles, Angela Bonifati, Stefania Dumbrava +18
Property graphs have reached a high level of maturity, witnessed by multiple robust graph database systems as well as the ongoing ISO standardization effort aiming at creating a ne…
GPC: A Pattern Calculus for Property Graphs
Nadime Francis, Amélie Gheerbrant, Paolo Guagliardo +7
The development of practical query languages for graph databases runs well ahead of the underlying theory. The ISO committee in charge of database query languages is currently deve…
Graph Pattern Matching in GQL and SQL/PGQ
Alin Deutsch, Nadime Francis, Alastair Green +15
As graph databases become widespread, JTC1 -- the committee in joint charge of information technology standards for the International Organization for Standardization (ISO), and In…
Threshold Queries in Theory and in the Wild
Angela Bonifati, Stefania Dumbrava, George Fletcher +7
Threshold queries are an important class of queries that only require computing or counting answers up to a specified threshold value. To the best of our knowledge, threshold queri…
The Future is Big Graphs! A Community View on Graph Processing Systems
Sherif Sakr, Angela Bonifati, Hannes Voigt +38
Graphs are by nature unifying abstractions that can leverage interconnectedness to represent, explore, predict, and explain real- and digital-world phenomena. Although real users a…
Holding a Conference Online and Live due to COVID-19
Angela Bonifati, Giovanna Guerrini, Carsten Lutz +6
The joint EDBT/ICDT conference (International Conference on Extending Database Technology/International Conference on Database Theory) is a well established conference series on da…
Containment of Simple Regular Path Queries
Diego Figueira, Adwait Godbole, S. Krishna +3
Testing containment of queries is a fundamental reasoning task in knowledge representation. We study here the containment problem for Conjunctive Regular Path Queries (CRPQs), a na…
The Complexity of Aggregates over Extractions by Regular Expressions
Johannes Doleschal, Benny Kimelfeld, Wim Martens
Regular expressions with capture variables, also known as regex-formulas, extract relations of spans (intervals identified by their start and end indices) from text. In turn, the c…
Weight Annotation in Information Extraction
Johannes Doleschal, Benny Kimelfeld, Wim Martens +1
The framework of document spanners abstracts the task of information extraction from text as a function that maps every document (a string) into a relation over the document's span…
A Trichotomy for Regular Trail Queries
Wim Martens, Matthias Niewerth, Tina Popp
Regular path queries (RPQs) are an essential component of graph query languages. Such queries consider a regular expression r and a directed edge-labeled graph G and search for pat…
Split-Correctness in Information Extraction
Johannes Doleschal, Benny Kimelfeld, Wim Martens +2
Programs for extracting structured information from text, namely information extractors, often operate separately on document segments obtained from a generic splitting operation s…
Enumeration Problems for Regular Path Queries
Wim Martens, Tina Trautner
Evaluation of regular path queries (RPQs) is a central problem in graph databases. We investigate the corresponding enumeration problem, that is, given a graph and an RPQ, enumerat…
An Analytical Study of Large SPARQL Query Logs
Angela Bonifati, Wim Martens, Thomas Timm
With the adoption of RDF as the data model for Linked Data and the Semantic Web, query specification from end- users has become more and more common in SPARQL end- points. In this…
Research Directions for Principles of Data Management (Dagstuhl Perspectives Workshop 16151)
Serge Abiteboul, Marcelo Arenas, Pablo Barceló +18
In April 2016, a community of researchers working in the area of Principles of Data Management (PDM) joined in a workshop at the Dagstuhl Castle in Germany. The workshop was organi…
SCULPT: A Schema Language for Tabular Data on the Web
Wim Martens, Frank Neven, Stijn Vansummeren
Inspired by the recent working effort towards a recommendation by the World Wide Web Consortium (W3C) for tabular data and metadata on the Web, we present in this paper a concept f…
A Characterization for Decidable Separability by Piecewise Testable Languages
Wojciech Czerwiński, Wim Martens, Lorijn van Rooijen +2
The separability problem for word languages of a class by languages of a class asks, for two given languages and from , whether the…
Efficient Separability of Regular Languages by Subsequences and Suffixes
Wojciech Czerwiński, Wim Martens, Tomáš Masopust
When can two regular word languages K and L be separated by a simple language? We investigate this question and consider separation by piecewise- and suffix-testable languages and…
On Typechecking Top-Down XML Tranformations: Fixed Input or Output Schemas
Wim Martens, Frank Neven, Marc Gyssens
Typechecking consists of statically verifying whether the output of an XML transformation always conforms to an output type for documents satisfying a given input type. In this gen…