Filters








389 Hits in 5.8 sec

An efficient SQL-based querying method to RDF schemata

Maciej Falkowski, Czeslaw Jedrzejek
2009 Control and Cybernetics  
In this work a method of query rewriting is presented that translates a query to an RDF data structure (i.e. SPARQL query) to a SQL query executed by RDBMS.  ...  Traditionally, in this area relational data are transformed to a form expected by reasoning and querying systems (usually RDF based).  ...  Use of RDF based representations results in a lower query efficiency.  ... 
dblp:journals/control/FalkowskiJ09 fatcat:j6ndfss7bjdlbb5kjvwy6g2g4e

Distributed Query Processing on the Cloud: the Optique Point of View (Short Paper)

Herald Kllapi, Dimitris Bilidas, Ian Horrocks, Yannis E. Ioannidis, Ernesto Jiménez-Ruiz, Evgeny Kharlamov, Manolis Koubarakis, Dmitriy Zheleznyakov
2013 W3C Web Ontology Language (OWL) Experiences and Directions Workshop (OWLED)  
The Optique European project 3 [6] aims at providing an end-to-end solution for scalable access to Big Data integration, where end users will formulate queries based on a familiar conceptualization of  ...  In this paper we present the distributed query processing engine of the Optique platform. The efficient execution of complex queries posed by end users is an important and challenging task.  ...  Conclusions The efficient execution of SQL queries on big data is an open research problem and initial results achieved by research prototypes such as HadoopDB are encouraging.  ... 
dblp:conf/owled/KllapiBHIJKKZ13 fatcat:td37tswk35clveokyztjx4mmgm

R2LD: Schema-based Graph Mapping of relational databases to Linked Open Data for multimedia resources data

Zhanfang Zhao, SungKook Han, JuRi Kim
2019 Multimedia tools and applications  
The schema-based mapping R2LD provides an efficient way to implement SPARQL endpoint into RDB and preserve the performance of SQL, which is vital to the dissemination of LOD. extend the current Web of  ...  The translation of SPARQL queries into equivalent SQL queries is one of the crux issues in RDB2RDF [5, 8] . This paper proposes a noble and practical method based on schema translation for RDB2RDF.  ...  the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.  ... 
doi:10.1007/s11042-019-7281-5 fatcat:gucb2iewmzbjrahehxzfajznti

3store: Efficient Bulk RDF Storage

Stephen Harris, Nicholas Gibbins
2003 Practical and Scalable Semantic Systems  
the efficient handling of large RDF knowledge bases.  ...  other RDF data and schemata that will be needed at a later date.  ...  Query execution As mentioned in Section 4.2, the 3store RDQL engine transforms an RDQL query into an SQL query over the underlying RDBMS representation of the RDF data.  ... 
dblp:conf/psss/HarrisG03 fatcat:uwdzdwogwnhkpfpq5jlaylih7i

SPARQL Update queries over R2RML mapped data sources

Jörg Unbehauen, Michael Martin
2017 Jahrestagung der Gesellschaft für Informatik  
SPARQL-to-SQL rewriters create virtual RDF without materializing data by exposing SPARQL endpoints.  ...  In the Linked Data Life Cycle mapping and extracting data from structured sources is an essential step in building a knowledge graph.  ...  insert has to be rejected or processed by an other update method.  ... 
doi:10.18420/in2017_189 dblp:conf/gi/UnbehauenM17 fatcat:y6uidqfpvnfpnefhl62vpitxkm

An In-depth Investigation of Large-scale RDF Relational Schema Optimizations Using Spark-SQL

Mohamed Ragab, Riccardo Tommasini, Feras M. Awaysheh, Juan Carlos Ramos
2021 International Workshop on Data Warehousing and OLAP  
This paper presents an in-depth investigation for practitioners to understand such trade-offs and their best practices.  ...  The choice of RDF partitioning techniques and storage formats using SparkSQL significantly impacts query performance.  ...  They combine structural non-quotient and statistical methods to automatically discover and detect an emergent relational schema (in the form of property tables) in RDF datasets.  ... 
dblp:conf/dolap/00010AR21 fatcat:fzl5ripxdfbgjmwwspf4n5iuce

A RDF-based Data Integration Framework [article]

Amineh Amini, Hadi Saboohi, Nasser Nemat bakhsh
2012 arXiv   pre-print
An approach is to provide an integrated mediated schema for various data sources. This research work aims at developing a framework for defining an integrated schema and querying on it.  ...  RDF is used for integrated schema descriptions as well as providing a unified view of data. RDQL is used for query reformulation.  ...  OUTPUT: a corresponding RDQL statement METHOD: 1-Create a unique name for any table in SQL query (in "?  ... 
arXiv:1211.6273v1 fatcat:r3a64vsuyzemjdmwllou6staeu

TritanDB: Time-series Rapid Internet of Things Analytics [article]

Eugene Siow, Thanassis Tiropanis, Xin Wang, Wendy Hall
2018 arXiv   pre-print
A query translation method with low overhead even on resource-constrained Things allows us to utilise rich data models like the Resource Description Framework (RDF) for interoperability and data integration  ...  The efficient management of data is an important prerequisite for realising the potential of the Internet of Things (IoT).  ...  It can be seen that expressive SQL and SQL-like query languages provide the most query support and in this work we seek to build on this expressiveness with the rich data model of RDF and its associated  ... 
arXiv:1801.07947v1 fatcat:4ps3plm26rfvjgulpnxc76zzam

Knowledge Extraction from Structured Sources [chapter]

Jörg Unbehauen, Sebastian Hellmann, Sören Auer, Claus Stadler
2012 Lecture Notes in Computer Science  
As an example, we provide a formalization and description of SparqlMap, which implements the relational database to RDF mapping language R2RML currently being standardized by the W3C.  ...  We summarize current progress on conversion of structured data to RDF and OWL.  ...  Acknowledgments We would like to thank our colleagues from AKSW research group for their helpful comments and inspiring discussions during the development of SparqlMap.  ... 
doi:10.1007/978-3-642-34213-4_3 fatcat:txmhb6vgpvhhxhluad66efalza

Semantic access to streaming and static data at Siemens

Evgeny Kharlamov, Theofilos Mailis, Gulnar Mehdi, Christian Neuenstadt, Özgür Özçep, Mikhail Roshchin, Nina Solomakhina, Ahmet Soylu, Christoforos Svingos, Sebastian Brandt, Martin Giese, Yannis Ioannidis (+4 others)
2017 Journal of Web Semantics  
We advocate Ontology Based Data Access (OBDA) as a suitable Semantic Web driven technology to address the challenge.  ...  The platform is based on a number of novel techniques and components including a deployment module, BootOX for ontology and mapping bootstrapping, a query language STARQL that allows for a uniform querying  ...  These mappings can be used to unfold the SPARQL query Q 2 into an SQL query Q 3 .  ... 
doi:10.1016/j.websem.2017.02.001 fatcat:vbyec4wq3rc5nntgpp35bc4fwa

RDF Storage and Retrieval Systems [chapter]

Alice Hertel, Jeen Broekstra, Heiner Stuckenschmidt
2009 Handbook on Ontologies  
We discuss different storage models, typical functionalities of RDF middleware such as data model support and reasoning capabilities and RDF query languages with a special focus on SPARQL as an emerging  ...  Ontologies are often used to improve data access. For this purpose, existing data has to be linked to an ontology and appropriate access mechanisms have to be provided.  ...  Architecture of RDF Stores An RDF store allows storage of RDF data and schema information, and provides methods to access that information.  ... 
doi:10.1007/978-3-540-92673-3_22 dblp:series/ihis/HertelBS09 fatcat:atuhk24ekbf5thcqsgeznuxyhu

RDFKB

James P. McGlothlin, Latifur R. Khan
2009 Proceedings of the 2009 International Database Engineering & Applications Symposium on - IDEAS '09  
These inference rules can be applied to RDF datasets to derive additional facts through methods such as subsumption, symmetry and transitive closure.  ...  RDFKB (Resource Description Framework Knowledge Base) is a relational database system for RDF datasets which supports inference and knowledge management.  ...  engine for RDF [17] , Neumann et al. propose a RDF indexing system with an efficient query processor.  ... 
doi:10.1145/1620432.1620460 dblp:conf/ideas/McGlothlinK09 fatcat:a4jslvpz2zbnzhnrikyogvgcji

An Experimental Comparison of RDF Data Management Approaches in a SPARQL Benchmark Scenario [chapter]

Michael Schmidt, Thomas Hornung, Norbert Küchlin, Georg Lausen, Christoph Pinkel
2008 Lecture Notes in Computer Science  
Efficient RDF data management is one of the cornerstones in realizing the Semantic Web vision.  ...  , subject, object) sort order, (2) in our scenario with real-world queries, none of the approaches scales to documents containing tens of millions of RDF triples, and (3) none of the approaches can compete  ...  The authors thank the MonetDB team for its support in setting up MonetDB and interesting discussions on RDF storage technologies.  ... 
doi:10.1007/978-3-540-88564-1_6 fatcat:6nxoc2l6w5a5hh2zixxflbm55u

A Distributed Query Execution Method for RDF Storage Managers

Kiyoshi Nitta, Iztok Savnik
2014 International Semantic Web Conference  
Method is intended for use with an RDF storage manager called big3store to enable it to perform efficient query execution over large-scale RDF data sets.  ...  A distributed query execution method for Resource Description Framework (RDF) storage managers is proposed.  ...  statistics to cope with an RDF store based on a single table, and ensuring efficient storage of RDF data.  ... 
dblp:conf/semweb/NittaS14 fatcat:wxmg3a2j6vayzj3dzjhhtuqtlm

Web Engineering: the Developers' View and a Practitioner's Approach [chapter]

Sotiris P. Christodoulou, Paris A. Zafiris, Theodore S. Papatheodorou
2001 Lecture Notes in Computer Science  
We propose a framework (RDF/XML based) that will act as a malleable development support environment, incorporating specific guidelines, which Web developers should always consider.  ...  The primary goals are achieving scalability (modular, component-based architecture), re-usability and technology independency in Web development. We focus on hypermedia content and applications.  ...  RDF and XML schemata are also valid XML files (according to their DTDs), enabling the application of XML content management tools to both RDF and XML schema management.  ... 
doi:10.1007/3-540-45144-7_17 fatcat:opywb7mv6vgfrh72ew4vsqvjs4
« Previous Showing results 1 — 15 out of 389 results