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Hierarchical Characteristic Set Merging for Optimizing SPARQL Queries in Heterogeneous RDF [article]

Marios Meimaris, George Papastefanatos
2018 arXiv   pre-print
Characteristic sets (CS) organize RDF triples based on the set of properties characterizing their subject nodes.  ...  This concept is recently used in indexing techniques, as it can capture the implicit schema of RDF data.  ...  In our previous work [8] , we defined Extended Characteristic Sets (ECSs) as typed links betwen CSs, and we showed how ECSs can be used to index triples and greatly improve query performance.  ... 
arXiv:1809.02345v1 fatcat:6vuyp5oam5ezvhmpfzvybssm2q

Storing, Indexing and Querying Large Provenance Data Sets as RDF Graphs in Apache HBase

Artem Chebotko, John Abraham, Pearl Brazier, Anthony Piazza, Andrey Kashlev, Shiyong Lu
2013 2013 IEEE Ninth World Congress on Services  
Specifically, we propose: (i) novel storage and indexing techniques for RDF data in HBase that are better suited for provenance datasets rather than generic RDF graphs and (ii) novel SPARQL query evaluation  ...  In this work, we explore and address the challenge of efficient and scalable storage and querying of large collections of provenance graphs serialized as RDF graphs in an Apache HBase database.  ...  SPARQL queries in HBase that are optimized to make use of bitmap indices and numeric values instead of triples.  ... 
doi:10.1109/services.2013.32 dblp:conf/services/ChebotkoABPKL13 fatcat:iodufllupzerzittn5prlweir4

Efficiently Querying RDF(S) Ontologies with Answer Set Programming

G. Ianni, A. Martello, C. Panetta, G. Terracina
2008 Journal of Logic and Computation  
Then, based on a previous result showing that the SPARQL query language (a candidate W3C recommendation for RDF(S) ontologies) can be mapped to a rule-based language, it shows that efficient querying of  ...  To date, most research efforts have been spent on the development of sufficiently expressive languages for the representation and querying of ontologies; however, querying efficiency has received attention  ...  Answer Set Programming with External Predicates As reference language for the internal querying engine, we adopt Answer Set Programming extended with external predicates (hereafter ASP EX ).  ... 
doi:10.1093/logcom/exn043 fatcat:mfx34qrpebf27kgyfhqy3cufoy

Querying and reasoning over large scale building data sets

Pieter Pauwels, Tarcisio Mendes de Farias, Chi Zhang, Ana Roxin, Jakob Beetz, Jos De Roo
2016 Proceedings of the International Workshop on Semantic Big Data - SBD '16  
Yet, hardly any benchmark is available for this industry that (1) gives an overview of the kind of data typically handled in this domain; and (2) that lists the query and reasoning performance results  ...  This has resulted in large semantic RDF graphs that are to be combined with a significant number of other data sets (building product catalogues, regulation data, geometric point cloud data, simulation  ...  RS6 Extends Rule Set 5 and Rule Set 1 with 6 additional rules for inferring whether an objet is internal or external to a building.  ... 
doi:10.1145/2928294.2928303 dblp:conf/sigmod/PauwelsFZRBR16 fatcat:jnwohmbr3jcs5c56ssym453nxe

Setting up a Global Linked Data Catalog of Datasets for Agriculture [chapter]

Valeria Pesce, Ajit Maru, Phil Archer, Thembani Malapela, Johannes Keizer
2015 Communications in Computer and Information Science  
Commonly agreed semantics, authority lists to index datasets and standard formats and protocols to expose data are now essential.  ...  This paper explains how the CIARD RING provides a global linked data catalog of datasets for agriculture.  ...  is accessible through an API that supports the identification of a subset by limiting to a set (like OAI-PMH) or a graph (like SPARQL).  ... 
doi:10.1007/978-3-319-24129-6_31 fatcat:nsfvivrb6fhc3n4suf5ydkahce

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
techniques for efficiently evaluating SPARQL queries in a local setting (on one machine).  ...  This survey paper provides a comprehensive review of techniques and systems for querying RDF knowledge graphs.  ...  AxonDB [155] uses extended characteristic sets where each triple (s, p, o) in the RDF graph is indexed with the signatures (i.e., characteristic sets) of its subject and object; i.e., (Σ(s), Σ(o)).  ... 
arXiv:2102.13027v4 fatcat:phontczhbfcvdjt5y75n3hfcge

Heuristics-based query optimisation for SPARQL

Petros Tsialiamanis, Lefteris Sidirourgos, Irini Fundulaki, Vassilis Christophides, Peter Boncz
2012 Proceedings of the 15th International Conference on Extending Database Technology - EDBT '12  
For this, we define the variable graph and we show a reduction of the SPARQL query optimization problem to the maximum weight independent set problem.  ...  In this paper we describe a set of useful heuristics for SPARQL query optimizers.  ...  Finally, it builds indexes on frequently occurring data paths that store exact join statistics for them. All the above indexes are exploited for query optimization.  ... 
doi:10.1145/2247596.2247635 dblp:conf/edbt/TsialiamanisSFCB12 fatcat:onpf27gmvndabivryphmeczcse

SparkRDF: Elastic Discreted RDF Graph Processing Engine With Distributed Memory

Xi Chen, Huajun Chen, Ningyu Zhang, Songyang Zhang
2015 2015 IEEE/WIC/ACM International Conference on Web Intelligence and Intelligent Agent Technology (WI-IAT)  
For SPARQL query optimization, SparkRDF generates an optimal execution plan for join queries, leading to effective reduction on the size of intermediate results, the number of joins and the cost of communication  ...  To reduce the high I/O and communication costs for distributed platforms, SparkRDF implements SPARQL query based on Spark, a novel in-memory distributed computing framework.  ...  indexes, whose goal is to construct a smaller index file for every TP in the SPARQL query.  ... 
doi:10.1109/wi-iat.2015.186 dblp:conf/webi/ChenCZZ15 fatcat:zgje652vt5f3ria4f7m3bdxzbi

Supporting Decentralized SPARQL Queries in an Ad-Hoc Semantic Web Data Sharing System

Jing Zhou, Gregor v. Bochmann, Zhongzhi Shi
2014 International Journal of Networking and Computing  
The effectiveness and efficiency of the SPARQL query processing mechanism we proposed for a decentralized settings were verified through a series of experiments.  ...  query processing for database systems and relational algebra optimization.  ...  Schmidt et al. identify a large set of algebraic equivalences for the SPARQL algebra which can serve as rewriting rules for query optimization [25] .  ... 
doi:10.15803/ijnc.4.1_88 fatcat:ef6aow4lqjaxth5bgq2kwwcbe4

Efficient Query Processing in RDF Databases [chapter]

Andrey Gubichev, Thomas Neumann
2014 Emerging Directions in Database Systems and Applications  
In this paper we show that the techniques borrowed from traditional SQL query optimization (such as Dynamic Programming algorithm or greedy heuristics) are not immediately capable of handling large SPARQL  ...  ., they represent RDF data as a single table with three attributes, at least conceptually), the query optimization strategies employed by such systems are often adopted from relational query optimization  ...  Query Graph and SPARQL Graph Given a SPARQL query, the query engine starts off with constructing its representation called a query graph.  ... 
doi:10.1201/b16859-8 fatcat:xu6mdl3uvnhmzcvzdbap2i2eiq

Self-organizing structured RDF in MonetDB

M. Pham
2013 2013 IEEE 29th International Conference on Data Engineering Workshops (ICDEW)  
Apart from performance issues, users of huge RDF graphs often have problems formulating queries as they lack any systemsupported notion of the structure in the data.  ...  This research aims to produce a state-of-the-art SPARQL frontend for MonetDB as a by-product, and we already present some preliminary results on this platform.  ...  For S OIDs: • we group them by characteristic sets. • within a characteristic set, we can then further suborder them on some index keys (i.e. property values).  ... 
doi:10.1109/icdew.2013.6547471 dblp:conf/icde/Pham13 fatcat:ai5u4ifvb5hihaboub6wzdevby

Resource Description Framework (RDF) [chapter]

2017 Encyclopedia of GIS  
The effectiveness and efficiency of the SPARQL query processing mechanism we proposed for a decentralized settings were verified through a series of experiments.  ...  query processing for database systems and relational algebra optimization.  ...  Schmidt et al. identify a large set of algebraic equivalences for the SPARQL algebra which can serve as rewriting rules for query optimization [25] .  ... 
doi:10.1007/978-3-319-17885-1_101108 fatcat:7ct5oskm4ngkfodejbyw3afutm

Federated Data Management and Query Optimization for Linked Open Data [chapter]

Olaf Görlitz, Steffen Staab
2011 Studies in Computational Intelligence  
Since Linked Open Data is based on standards like the RDF format and the SPARQL query language, it is possible to implement a federation infrastructure without the need for specific data wrappers.  ...  In this chapter we consider some details and implications of these limitations and presents an improved query optimization approach based on dynamic programming.  ...  Networked RDF Graphs [51] extend named graphs with a SPARQL based view mechanism.  ... 
doi:10.1007/978-3-642-17551-0_5 fatcat:4xbxxkewrbhifpir6sr57cmxay

R3F: RDF triple filtering method for efficient SPARQL query processing

Kisung Kim, Bongki Moon, Hyoung-Joo Kim
2013 World wide web (Bussum)  
With the rapid growth in the amount of graph-structured Resource Description Framework (RDF) data, SPARQL query processing has received significant attention.  ...  We design a path-based index called the RDF Path index (RP-index) to efficiently provide filter data for the triple filtering.  ...  For SPARQL query Q, the substitution θ is a mapping V Q ∩ VAR → U. θ(G Q ) is a graph whose variables are substituted according to θ . The answer set for a SPARQL query is defined as follows.  ... 
doi:10.1007/s11280-013-0253-1 fatcat:pqi4li4yrnbhlfvqjf4y6lpese

RDF Query Answering Using Apache Spark: Review and Assessment

Giannis Agathangelos, Georgia Troullinou, Haridimos Kondylakis, Kostas Stefanidis, Dimitris Plexousakis
2018 2018 IEEE 34th International Conference on Data Engineering Workshops (ICDEW)  
The explosion of the web and the abundance of linked data demand for effective and efficient methods for storage, management and querying.  ...  We discuss on the characteristics and the key dimension of such systems, we describe novel ideas in the area, and the corresponding drawbacks, and provide directions for future work.  ...  Essentially, SPARQL is a graph-matching language. SPARQL queries contain a set of triples patterns, also called basic graph patterns.  ... 
doi:10.1109/icdew.2018.00016 dblp:conf/icde/AgathangelosTKS18 fatcat:ji7puutbmfbaln667f5nvz3uzq
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