Filters








9 Hits in 4.8 sec

A Survey of RDF Stores SPARQL Engines for Querying Knowledge Graphs [article]

Waqas Ali, Muhammad Saleem, Bin Yao, Aidan Hogan, Axel-Cyrille Ngonga Ngomo
2021 arXiv   pre-print
RDF has seen increased adoption in recent years, prompting the standardization of the SPARQL query language for RDF, and the development of local and distributed engines for processing SPARQL queries.  ...  queries in a local setting (on one machine).  ...  Various new features were added in SPARQL 1.1, such as property paths for matching arbitrarylength paths in the RDF graph.  ... 
arXiv:2102.13027v4 fatcat:phontczhbfcvdjt5y75n3hfcge

Querying Semantic Knowledge Bases with SQL-on-Hadoop

Martin Przyjaciel-Zablocki, Alexander Schätzle, Georg Lausen
2017 Proceedings of the 4th Algorithms and Systems on MapReduce and Beyond - BeyondMR'17  
However, SPARQL, the W3C standard query language for RDF, suffers from a rather limited capability to express navigational queries.  ...  Comprehensive experiments examine the performance of our system in comparison to other competitive RDF management systems.  ...  At most, SPARQL 1.1 Property Paths are supported via Virtuoso Cluster as being the only available distributed RDF management system that runs on a cluster of machines [11] .  ... 
doi:10.1145/3070607.3070610 dblp:conf/sigmod/Przyjaciel-Zablocki17 fatcat:wt42dwt6infpzn2ywq6n564vlu

A design space for RDF data representations

Tomer Sagi, Matteo Lissandrini, Torben Bach Pedersen, Katja Hose
2022 The VLDB journal  
We complement the review with an empirical evaluation of ten standard SPARQL benchmarks to examine the prevalence of these access patterns in synthetic and real query workloads.  ...  Within this design space, we map the trade-offs between different RDF data representations employed as part of an RDF triplestore and identify unexplored solutions.  ...  A number of systems (RDF-3X [55] , Sparqling kleene [31] , Virtuoso [24] , YARS2 [36] ) employ block-level compression.  ... 
doi:10.1007/s00778-021-00725-x fatcat:rj5y2e3lrbhbfhhhmteslr42im

GPU-based Commonsense Paradigms Reasoning for Real-Time Query Answering and Multimodal Analysis [article]

Nguyen Ha Tran, Erik Cambria
2018 arXiv   pre-print
In addition, in order to ex- tract important textual features from multimodal sources we generate domain-specific graphs based on commonsense knowledge and apply GPU-based graph traversal for fast feature  ...  In particular, we focus on the problem of multimodal sentiment analysis, which consists in the simultaneous analysis of different modali- ties, e.g., speech and video, for emotion and polarity detection  ...  This encoding is commonly used in large-scale triple stores such as RDF-3X [34] and Hexastore [125] to reduce tuple space and faster comparison.  ... 
arXiv:1807.08804v1 fatcat:xu5m2oh55ndahct7rtrbecjz3m

An Analysis of the Feasibility of Graph Compression Techniques for Indexing Regular Path Queries

Frank Tetzel, Hannes Voigt, Marcus Paradies, Wolfgang Lehner
2017 Proceedings of the Fifth International Workshop on Graph Data-management Experiences & Systems - GRADES'17  
Regular path queries (RPQs) are a fundamental part of recent graph query languages like SPARQL and PGQL.  ...  They allow the de nition of recursive path structures through regular expressions in a declarative pattern matching environment.  ...  RPQ PROCESSING IN COLUMN STORES RPQs can operate on a range on di erent graph data models, such as the RDF and the Property Graph data model.  ... 
doi:10.1145/3078447.3078458 dblp:conf/grades/TetzelVPL17 fatcat:5qf3n32b5bhq3j3hrknxmi27qu

Distributed querying of large labeled graphs [article]

Sairam Gurajada, Universität Des Saarlandes, Universität Des Saarlandes
2017
In this thesis, we advance the state-of-the-art for the following query models, and propose a distributed solution to process them in an e cient and scalable manner. 2  ...  Graph is a vital abstract data type that has profound signi cance in several applications.  ...  Acknowledgements We implemented our approach in TriAD RDF engine (discussed in Chapter 4) . We used GCC-4. 7 .3 with -O3 optimization and MPICH2-1.4.1 and Boost-1.55 as external libraries.  ... 
doi:10.22028/d291-26695 fatcat:emcbwfkycja3jfnebwfy64rwum

Algorithmic building blocks for relationship analysis over large graphs [article]

Stephan Seufert, Universität Des Saarlandes, Universität Des Saarlandes
2015
For efficient processing of SPARQL queries, RDF-3X is relying primarily on merge-joins, with a query optimizer concentrating on the join order.  ...  country isCalled "United States" } Here, the variable length subpath of edges with property locatedIn is expressed using Kleene star notation. In SPARQL, joins are expressed using dot notation.  ...  Connection to Query Entities 6.5 with 1 to |Q| (depending on the scenario) of the query entities, employing a dynamic programming algorithm to identify good paths.  ... 
doi:10.22028/d291-25420 fatcat:p53vkf4c3zgrfme2emwwzyjb2y

Cost-based optimization of graph queries in relational database management systems [article]

Silke Trissl, Humboldt-Universität Zu Berlin, Humboldt-Universität Zu Berlin
2017
We propose the reachability, distance, path length, and path operator.  ...  Graphen sind in vielen Bereichen des Lebens zu finden, wobei wir speziell an Graphen in der Biologie interessiert sind.  ...  The W3C also provides a recommendation for querying RDF graphs, called SPARQL [PS08] .  ... 
doi:10.18452/16544 fatcat:tcc77jtorzcr3hz46xp5ncff6u

Accelerating Event Stream Processing in On- and Offline Systems

Michael Körber, Datenbanksysteme, Seeger, Bernhard (Prof. Dr.)
2022
In parti [...]  ...  In this thesis, we consider two kinds of event stream processing: online and offline.  ...  Acknowledgments When I started my academic journey back in 2010, I never thought that I would end up here.  ... 
doi:10.17192/z2022.0078 fatcat:x64m6dluzjhhzi7mycwod7lkhq