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Efficiently Evaluating Skyline Queries on RDF Databases [chapter]

Ling Chen, Sidan Gao, Kemafor Anyanwu
2011 Lecture Notes in Computer Science  
In this paper, we present an approach for optimizing skyline queries over RDF data stored using a vertically partitioned schema model.  ...  While this problem has received significant attention in the context of single relational table, skyline queries over joins of multiple tables that are typical of storage models for RDF data has received  ...  Conclusion and Future Work In this paper, we have addressed the problem of skyline queries over RDF databases.  ... 
doi:10.1007/978-3-642-21064-8_9 fatcat:q5pwmfufabe3jbvhiugrjavveu

Handling qualitative preferences in SPARQL over virtual ontology-based data access

Marlene Goncalves, David Chaves-Fraga, Oscar Corcho, Axel-Cyrille Ngonga Ngomo, Muhammad Saleem, Ruben Verborgh
2022 Semantic Web Journal  
Our main contribution is Morph-Skyline++, a framework for processing SPARQL qualitative preferences by directly querying relational databases.  ...  Our framework implements a technique that translates SPARQL qualitative preference queries directly into queries that can be evaluated by a relational database management system.  ...  H 5 QualQT executed by Morph-Skyline++ performs better at runtime than the current SPARQL-based approaches on materialized RDF for skyline query evaluation.  ... 
doi:10.3233/sw-212895 fatcat:fymhzoy3wnfhxmmirvmgv3vhpm

Skyline Modeling and Computing over Trust RDF Data

Amna Abidi, Mohamed Anis Bach Tobji, Allel Hadjali, Boutheina Ben Yaghlane
2017 Proceedings of the 19th International Conference on Enterprise Information Systems  
In this paper, we are interested in querying trust RDF data.  ...  Efficient methods to compute the trust-skyline are provided and compared to some existing approaches as well.  ...  We also presented an SQL query to show how Trust-Skyline can be implemented on a relational database system. Our experiments showed the efficiency of the TRDF-Skyline algorithm.  ... 
doi:10.5220/0006320706340643 dblp:conf/iceis/AbidiTHY17 fatcat:cqskvymi5fa7hcemg67g7eckvm

SkyPackage: From Finding Items to Finding a Skyline of Packages on the Semantic Web [chapter]

Matthew Sessoms, Kemafor Anyanwu
2013 Lecture Notes in Computer Science  
on computing item skylines.  ...  We formalize the problem and discuss our implementation strategy for a loose integration with an open source RDF system, and evaluate the algorithm using synthetic and real world datasets.  ...  Nagiza Samatova, who spent time and efforts on reviewing my thesis. I am indebted to NC State for giving me the opportunity to gain invaluable experience and knowledge. iv  ... 
doi:10.1007/978-3-642-37996-3_4 fatcat:47zpjtq43rfbvijshgdwe2bale

Efficiently Producing the K Nearest Neighbors in the Skyline on Vertically Partitioned Tables

Marlene Goncalves, Maria-Esther Vidal
2013 International Journal of Information Retrieval Research  
The proposed algorithms identify among the skyline tuples, the k ones with the lowest values of the distance metric, i.e., the k nearest neighbors to the multi-dimensional query that are incomparable.  ...  to the query that are incomparable or belong to the skyline.  ...  Particularly, the task of evaluating queries based on user preferences may be considerably affected by this situation.  ... 
doi:10.4018/ijirr.2013040104 fatcat:zz7j2bd54vhidohoabv5grokgy

SPARQL extensions with preferences

Olivier Pivert, Olfa Slama, Virginie Thion
2016 Proceedings of the 31st Annual ACM Symposium on Applied Computing - SAC '16  
Even though most of the work has been devoted to relational databases, many proposals have also been made in the Semantic Web area in order to query RDF databases in a flexible way.  ...  The last decade has witnessed an increasing interest in expressing preferences inside database queries.  ...  ., 2013 have dealt with the expression and evaluation of skyline queries in a SPARQL-like language.  ... 
doi:10.1145/2851613.2851690 dblp:conf/sac/PivertST16 fatcat:7mnd3cdt6bewnlycpep2lcz7nu

Malleability-Aware Skyline Computation on Linked Open Data [chapter]

Christoph Lofi, Ulrich Güntzer, Wolf-Tilo Balke
2012 Lecture Notes in Computer Science  
In recent years, the skyline query paradigm has been established as a reliable and efficient method for database query personalization.  ...  However, this new view on dominance in turn has serious implications on the efficiency of the actual skyline computation, since transitivity of the dominance relationships is no longer granted.  ...  However, the developed algorithm has been designed for optimizing skyline queries over RDF data stored using a vertically partitioned schema model and thus presents an efficient scheme to interleave the  ... 
doi:10.1007/978-3-642-29035-0_3 fatcat:tw6lvmwv3zdg7drlzn6wxojfra

Cooperative Techniques for SPARQL Query Relaxation in RDF Databases [chapter]

Géraud Fokou, Stéphane Jean, Allel Hadjali, Mickael Baron
2015 Lecture Notes in Computer Science  
While previous works on query relaxation over RDF data have focused on defining new relaxation operators, we investigate in this paper techniques to find the parts of an RDF query that are responsible  ...  This paper addresses the problem of failing RDF queries. Query relaxation is one of the cooperative techniques that allows providing users with alternative answers instead of an empty result.  ...  We are concerned with computing the MFSs and XSSs of a failing RDF query over an RDF database efficiently.  ... 
doi:10.1007/978-3-319-18818-8_15 fatcat:tfwpz75luzfc5n4pq4uzsh3tki

Equivalence Heuristics for Malleability-Aware Skylines

Christoph Lofi, Wolf-Tilo Balke, Ulrich Guntzer
2012 Journal of Computing Science and Engineering  
In recent years, the skyline query paradigm has been established as a reliable method for database query personalization.  ...  This is necessary; because the new view on linked open data dominance has serious implications for the efficiency of the actual skyline computation, since transitivity of the dominance relationships is  ...  However, the developed algorithm has been designed for optimizing skyline queries over RDF data stored using a vertically partitioned schema model, and thus presents an efficient scheme to interleave the  ... 
doi:10.5626/jcse.2012.6.3.207 fatcat:ksvzs7md3bc6vk54gfkyftym3e

Distributed skyline processing

Katja Hose, Akrivi Vlachou
2012 Proceedings of the 15th International Conference on Extending Database Technology - EDBT '12  
The skyline operator has been proposed about a decade ago, but research on skyline queries, especially in distributed scenarios, is still an ongoing process.  ...  In this tutorial, we will outline the objectives and the main principles that any distributed skyline approach has to fulfill, leading to useful guidelines for the design of efficient distributed skyline  ...  Her current research interests range from query processing and optimization in distributed systems, heterogeneous databases, and rank-aware query operators to information retrieval, linked data, and RDF  ... 
doi:10.1145/2247596.2247665 dblp:conf/edbt/HoseV12 fatcat:thyyhjkc55h5xob3r3aiikn64q

Emerging Graph Queries in Linked Data

Arijit Khan, Yinghui Wu, Xifeng Yan
2012 2012 IEEE 28th International Conference on Data Engineering  
only on the structure of the network.  ...  While querying and mining these linked datasets are essential for various applications, traditional graph queries may not be able to capture the rich semantics in these networks.  ...  We shall introduce efficient techniques to answer such queries. Graph skyline.  ... 
doi:10.1109/icde.2012.143 dblp:conf/icde/KhanWY12 fatcat:fhj2klrjrrf2nhtcxhuak7wvdy

On answering why and why-not questions in databases

M. S. Islam
2013 2013 IEEE 29th International Conference on Data Engineering Workshops (ICDEW)  
query settings and (iii) finally, developing a framework that can take advantage of the existing data indexing and query evaluation techniques available to answer such questions in databases.  ...  This research aims at answering the so called why and why-not questions on received results w.r.t. different query settings in databases.  ...  The database varies from relational, XML, RDF and graphs.  ... 
doi:10.1109/icdew.2013.6547468 dblp:conf/icde/Islam13 fatcat:eqtwv7jz6ndqfpp6l3t4xjfo3u

Cost-Aware Skyline Queries in Structured Overlays

Marcel Karnstedt, Jessica Muller, Kai-Uwe Sattler
2007 2007 IEEE 23rd International Conference on Data Engineering Workshop  
On the level of query expressiveness, ranking queries like skyline queries are predestinated for providing a fast but concise overview of the data.  ...  In this work, we propose three variants of a skyline operator and two extensions, especially suitable for efficient determination of skylines in the before mentioned overlay systems.  ...  Skyline queries are intensively researched in the database community [3, 8, 9, 2, 12] .  ... 
doi:10.1109/icdew.2007.4401006 dblp:conf/icde/KarnstedtMS07 fatcat:gka6wf27ubfevlttirmhmgplum

Scalable Distributed Indexing and Query Processing Over Linked Data

Marcel Karnstedt, Kai-Uwe Sattler, Manfred Hauswirth
2012 Social Science Research Network  
Our approach is based on a logical algebra for queries over RDF data and a related physical query algebra to enable optimization, both on the logical and physical layers in query processing.  ...  A number of efficient local RDF stores exist already, while distributed indexing and distributed query processing over Linked Data with similar efficiency and data management features as known from traditional  ...  An evaluation in a large local cluster of powerful machines shows that the idea of efficient RDF query processing in DHT systems can scale to millions of triples.  ... 
doi:10.2139/ssrn.3198930 fatcat:k6ilnvk2fffzdgc2mhpryahoju

A DHT-based infrastructure for ad-hoc integration and querying of semantic data

Marcel Karnstedt, Kai-Uwe Sattler, Manfred Hauswirth, Roman Schmidt
2008 Proceedings of the 2008 international symposium on Database engineering & applications - IDEAS '08  
We focus on the integration into efficient distributed query processing and evaluate our approach in a series of experiments.  ...  In this paper, we argue for a unified and distributed infrastructure providing a repository for semantic data by offering location transparency and advanced query services.  ...  The objective of the following evaluation is to show that we can achieve our main requirement, which is efficiency in query processing.  ... 
doi:10.1145/1451940.1451945 dblp:conf/ideas/KarnstedtSHS08 fatcat:3opr76jhdnb65edf3kpz35mrli
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