A Comparison of Different Graph Database Types

Total Page:16

File Type:pdf, Size:1020Kb

A Comparison of Different Graph Database Types A comparison of different graph database types Jieru Yao August 22, 2018 MSc in High Performance Computing with Data Science The University of Edinburgh Year of Presentation: 2018 Abstract In an era of information and Internet, there is a great amount of data produced and changed every day by different enterprises and individuals. Database Management System (DBMS) as an effective and efficient way for data storage, data management, data maintaining and data security, has been highly popular in various area like Business, Industry and Education. Relational Database System as the most familiar one has been known by a great many people. Relational Database uses ‘Tables’ as basic storage units. The data with various types and categories in our real lives could be abstracted into different ‘Tables’ as entities, while the relationships are represented by the correlation table between two entities, which means a correlation table will be created when there is a relationship with two entities. Then, there will be a negative effect that a great deal of correlation tables will be produced if the relationships between entities is more than one. In other words, if the relationships among entities are complex, it is difficult for designers to model the data using a Relational Database. Therefore, an alternative type of database based on Graph structure need to be introduced to improve performance when above problems happen, which is Graph Database. Graph Database uses nodes and edges representing data with complex relationships. This basic concepts help DBMS arrange and simplify the sophisticated relationships of mass data sets, which contributes to improve the performance of database. More detailed information will be demonstrated and discussed in later chapters. The dissertation mainly focuses on the performance of two different types (i.e. RDF and LPG types) of Graph Databases. Their different storage data types will be tested and analysed according to different size of dataset running on Windows 10 System and Ubuntu 16.04 System. Contents Chapter 1 Introduction .................................................................................................... 1 1.1 The importance of Graph Database ......................................................................... 1 1.2 Objectives ................................................................................................................. 4 Chapter 2 Literature Review .......................................................................................... 5 2.1 Graph Databases ....................................................................................................... 5 2.2 RDF Graph Databases .............................................................................................. 6 2.2.1 RDF graph ......................................................................................................... 6 2.2.2 SPARQL ............................................................................................................ 8 2.2.3 OpenLink Virtuoso ............................................................................................ 8 2.3 Labeled Property Graph Database ........................................................................... 9 2.3.1 Labeled Property Graph .................................................................................... 9 2.3.2 Neo4j................................................................................................................12 2.4 Open source data sets available in RDF ................................................................12 2.4.1 DBpedia ...........................................................................................................12 2.5 Introduction of two formats of RDF data sets .......................................................13 2.5.1 Turtle ................................................................................................................13 2.5.2 N-triples ...........................................................................................................13 Chapter 3 Research Methodology ................................................................................14 3.1 Data sets preparation from DBpedia ......................................................................14 3.2 Loading RDF data sets into OpenLink Virtuoso database ....................................15 3.2.1 Loading RDF data sets into OpenLink Virtuoso database on Windows 10 system .............................................................................................................15 3.2.2 Loading RDF data sets into OpenLink Virtuoso database on Ubuntu 16.04 system .............................................................................................................18 3.3 Loading RDF data sets into Neo4 ..........................................................................19 3.3.1 Loading RDF data sets into Neo4j database on Windows 10 system ...........19 i 3.3.2 Loading RDF data sets into Neo4j database on Ubuntu 16.04 system..........20 3.4 Measuring loading times on Windows 10 system .................................................20 3.4.1 Measuring loading times of Virtuoso database on Windows 10 system .......21 3.4.2 Measuring loading times of Neo4j database on Windows 10 system ...........23 3.5 Measuring loading times on Ubuntu 16.04 system ...............................................24 3.5.1 Measuring loading times of Virtuoso database on Ubuntu 16.04 system .....25 3.5.2 Measuring loading times of Neo4j database on Ubuntu 16.04 system .........26 3.6 Measuring query times on Windows 10 system ....................................................26 3.6.1 Measuring query times of Virtuoso database on Windows 10 system ..........26 3.6.2 Measuring query times of Neo4j database on Windows 10 system ..............27 3.7 Measuring query times on Ubuntu 16.04 system ..................................................27 3.7.1 Measuring query times of Virtuoso database on Ubuntu 16.04 system ........27 3.7.2 Measuring query times of Neo4j database on Ubuntu 16.04 system ............27 Chapter 4 Experimental Work Carried ......................................................................28 4.1 Hardware and Software configurations of test systems ........................................28 4.1.1 Windows 10 system ........................................................................................28 4.1.2 Ubuntu 16.04 system .......................................................................................28 4.2 Virtuoso Installation ...............................................................................................29 4.2.1 Virtuoso Installation on Windows system ......................................................29 4.2.2 Virtuoso Installation on Ubuntu 16.04 ...........................................................31 4.3 Neo4j Installation ...................................................................................................32 4.3.1 Neo4j installation on Windows 10 system .....................................................32 4.3.2 Neo4j installation on Ubuntu 16.04 system ...................................................33 4.4 Transformation process from RDF graph to LPG .................................................33 4.4.1 How to use the transformation plugin in Neo4j on Windows 10 system ......39 4.4.2 How to use the transformation plugin in Neo4j on Ubuntu 16.04 system ....41 Chapter 5 Results and Analysis ....................................................................................43 5.1 Loading time of two database systems on Windows 10 system ...........................43 ii 5.1.1 Loading time of Virtuoso on Windows 10 system.........................................43 5.1.2 Loading time of Neo4j on Windows 10 system .............................................44 5.1.3 Comparison of loading time of both database systems on Windows system 45 5.2 Loading time of two database systems on Ubuntu system ...................................46 5.2.1 Loading time of Virtuoso on Ubuntu system .................................................46 5.2.2 Loading time of Neo4j on Ubuntu system .....................................................47 5.2.3 Comparison of loading time of both database systems on Ubuntu system ...49 5.3 Comparison of loading time on Windows system and Ubuntu system for Virtuoso .......................................................................................................................................50 5.4 Comparison of loading time on Windows system and Ubuntu system for Neo4j .......................................................................................................................................51 5.5 Query time of Virtuoso on both systems ...............................................................52 5.5.1 Query time of Virtuoso on Windows system .................................................52 5.5.2 Query time of Virtuoso on Ubuntu system.....................................................53 5.5.3 Comparison of query time on Windows system and Ubuntu system for Virtuoso ..........................................................................................................54 5.6 Query time of Neo4j on both systems ...................................................................54 5.6.1 Query time of Neo4j on Windows system .....................................................54 5.6.2 Query time of Neo4j on Ubuntu system .........................................................55
Recommended publications
  • Graph Database for Collaborative Communities Rania Soussi, Marie-Aude Aufaure, Hajer Baazaoui
    Graph Database for Collaborative Communities Rania Soussi, Marie-Aude Aufaure, Hajer Baazaoui To cite this version: Rania Soussi, Marie-Aude Aufaure, Hajer Baazaoui. Graph Database for Collaborative Communities. Community-Built Databases, Springer, pp.205-234, 2011. hal-00708222 HAL Id: hal-00708222 https://hal.archives-ouvertes.fr/hal-00708222 Submitted on 14 Jun 2012 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Graph Database For collaborative Communities 1, 2 1 Rania Soussi , Marie-Aude Aufaure , Hajer Baazaoui2 1Ecole Centrale Paris, Applied Mathematics & Systems Laboratory (MAS), SAP Business Objects Academic Chair in Business Intelligence 2Riadi-GDL Laboratory, ENSI – Manouba University, Tunis Abstract Data manipulated in an enterprise context are structured data as well as un- structured data such as emails, documents, social networks, etc. Graphs are a natural way of representing and modeling such data in a unified manner (Structured, semi-structured and unstructured ones). The main advantage of such a structure relies in the dynamic aspect and the capability to represent relations, even multiple ones, between objects. Recent database research work shows a growing interest in the definition of graph models and languages to allow a natural way of handling data appearing.
    [Show full text]
  • Semantics Developer's Guide
    MarkLogic Server Semantic Graph Developer’s Guide 2 MarkLogic 10 May, 2019 Last Revised: 10.0-8, October, 2021 Copyright © 2021 MarkLogic Corporation. All rights reserved. MarkLogic Server MarkLogic 10—May, 2019 Semantic Graph Developer’s Guide—Page 2 MarkLogic Server Table of Contents Table of Contents Semantic Graph Developer’s Guide 1.0 Introduction to Semantic Graphs in MarkLogic ..........................................11 1.1 Terminology ..........................................................................................................12 1.2 Linked Open Data .................................................................................................13 1.3 RDF Implementation in MarkLogic .....................................................................14 1.3.1 Using RDF in MarkLogic .........................................................................15 1.3.1.1 Storing RDF Triples in MarkLogic ...........................................17 1.3.1.2 Querying Triples .......................................................................18 1.3.2 RDF Data Model .......................................................................................20 1.3.3 Blank Node Identifiers ..............................................................................21 1.3.4 RDF Datatypes ..........................................................................................21 1.3.5 IRIs and Prefixes .......................................................................................22 1.3.5.1 IRIs ............................................................................................22
    [Show full text]
  • Rdfa in XHTML: Syntax and Processing Rdfa in XHTML: Syntax and Processing
    RDFa in XHTML: Syntax and Processing RDFa in XHTML: Syntax and Processing RDFa in XHTML: Syntax and Processing A collection of attributes and processing rules for extending XHTML to support RDF W3C Recommendation 14 October 2008 This version: http://www.w3.org/TR/2008/REC-rdfa-syntax-20081014 Latest version: http://www.w3.org/TR/rdfa-syntax Previous version: http://www.w3.org/TR/2008/PR-rdfa-syntax-20080904 Diff from previous version: rdfa-syntax-diff.html Editors: Ben Adida, Creative Commons [email protected] Mark Birbeck, webBackplane [email protected] Shane McCarron, Applied Testing and Technology, Inc. [email protected] Steven Pemberton, CWI Please refer to the errata for this document, which may include some normative corrections. This document is also available in these non-normative formats: PostScript version, PDF version, ZIP archive, and Gzip’d TAR archive. The English version of this specification is the only normative version. Non-normative translations may also be available. Copyright © 2007-2008 W3C® (MIT, ERCIM, Keio), All Rights Reserved. W3C liability, trademark and document use rules apply. Abstract The current Web is primarily made up of an enormous number of documents that have been created using HTML. These documents contain significant amounts of structured data, which is largely unavailable to tools and applications. When publishers can express this data more completely, and when tools can read it, a new world of user functionality becomes available, letting users transfer structured data between applications and web sites, and allowing browsing applications to improve the user experience: an event on a web page can be directly imported - 1 - How to Read this Document RDFa in XHTML: Syntax and Processing into a user’s desktop calendar; a license on a document can be detected so that users can be informed of their rights automatically; a photo’s creator, camera setting information, resolution, location and topic can be published as easily as the original photo itself, enabling structured search and sharing.
    [Show full text]
  • Semantic Gadgets: Pervasive Computing Meets the Semantic Web
    Semantic Gadgets: Pervasive Computing Meets the Semantic Web Ora Lassila Research Fellow Agent Technology Group, Nokia Research Center October 2002 1 © NOKIA 2002-10-01 - Ora Lassila Mobility Makes Things Different • Device location is a new dimension • more information about the user and the usage context available • new applications & services are possible • Devices are different • reduced capabilities: smaller screens, slow input devices, lower bandwidth, higher latency, worse reliability, … • trusted device: always with you & has access to your private data • Usage contexts and needs are different • awkward usage situations (e.g., in the car while driving) • specific needs (“surfing” unlikely) • you are always “on” (= connected) • Dilemma: • the Internet - by design - represents a departure from physical reality but mobility grounds services & users to the physical world 2 © NOKIA 2002-10-01 - Ora Lassila 1 Some Enablers of Mobile Internet • Access to services from handheld terminals • Dynamic synthesis of content • Context-sensitivity • location is one dimension of a “context”, but there are others • New Technologies • Artificial Intelligence • machine learning: automatic customization and adaptation • automated planning: autonomous operation • “Semantic Web” • intelligent synthesis of content from multiple sources (ad hoc & on demand) • explicit representation of semantics of data & services • Ubiquitous (aka Pervasive) Computing • (a paradigm shift in personal computing) 3 © NOKIA 2002-10-01 - Ora Lassila Semantic Web: Motivation
    [Show full text]
  • RDF Query Languages Need Support for Graph Properties
    RDF Query Languages Need Support for Graph Properties Renzo Angles1, Claudio Gutierrez1, and Jonathan Hayes1,2 1 Dept. of Computer Science, Universidad de Chile 2 Dept. of Computer Science, Technische Universit¨at Darmstadt, Germany {rangles,cgutierr,jhayes}@dcc.uchile.cl Abstract. This short paper discusses the need to include into RDF query languages the ability to directly query graph properties from RDF data. We study the support that current RDF query languages give to these features, to conclude that they are currently not supported. We propose a set of basic graph properties that should be added to RDF query languages and provide evidence for this view. 1 Introduction One of the main features of the Resource Description Framework (RDF) is its ability to interconnect information resources, resulting in a graph-like structure for which connectivity is a central notion [GLMB98]. As we will argue, basic concepts of graph theory such as degree, path, and diameter play an important role for applications that involve RDF querying. Considering the fact that the data model influences the set of operations that should be provided by a query language [HBEV04], it follows the need for graph operations support in RDF query languages. For example, the query “all relatives of degree 1 of Alice”, submitted to a genealogy database, amounts to retrieving the nodes adjacent to a resource. The query “are suspects A and B related?”, submitted to a police database, asks for any path connecting these resources in the (RDF) graph that is stored in this database. The query “what is the Erd˝osnumber of Alberto Mendelzon”, submitted to (a RDF version of) DBLP, asks simply for the length of the shortest path between the nodes representing Erd˝osand Mendelzon.
    [Show full text]
  • Property Graph Vs RDF Triple Store: a Comparison on Glycan Substructure Search
    RESEARCH ARTICLE Property Graph vs RDF Triple Store: A Comparison on Glycan Substructure Search Davide Alocci1,2, Julien Mariethoz1, Oliver Horlacher1,2, Jerven T. Bolleman3, Matthew P. Campbell4, Frederique Lisacek1,2* 1 Proteome Informatics Group, SIB Swiss Institute of Bioinformatics, Geneva, 1211, Switzerland, 2 Computer Science Department, University of Geneva, Geneva, 1227, Switzerland, 3 Swiss-Prot Group, SIB Swiss Institute of Bioinformatics, Geneva, 1211, Switzerland, 4 Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, Australia * [email protected] Abstract Resource description framework (RDF) and Property Graph databases are emerging tech- nologies that are used for storing graph-structured data. We compare these technologies OPEN ACCESS through a molecular biology use case: glycan substructure search. Glycans are branched Citation: Alocci D, Mariethoz J, Horlacher O, tree-like molecules composed of building blocks linked together by chemical bonds. The Bolleman JT, Campbell MP, Lisacek F (2015) molecular structure of a glycan can be encoded into a direct acyclic graph where each node Property Graph vs RDF Triple Store: A Comparison on Glycan Substructure Search. PLoS ONE 10(12): represents a building block and each edge serves as a chemical linkage between two build- e0144578. doi:10.1371/journal.pone.0144578 ing blocks. In this context, Graph databases are possible software solutions for storing gly- Editor: Manuela Helmer-Citterich, University of can structures and Graph query languages, such as SPARQL and Cypher, can be used to Rome Tor Vergata, ITALY perform a substructure search. Glycan substructure searching is an important feature for Received: July 16, 2015 querying structure and experimental glycan databases and retrieving biologically meaning- ful data.
    [Show full text]
  • Using Shape Expressions (Shex) to Share RDF Data Models and to Guide Curation with Rigorous Validation B Katherine Thornton1( ), Harold Solbrig2, Gregory S
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Repositorio Institucional de la Universidad de Oviedo Using Shape Expressions (ShEx) to Share RDF Data Models and to Guide Curation with Rigorous Validation B Katherine Thornton1( ), Harold Solbrig2, Gregory S. Stupp3, Jose Emilio Labra Gayo4, Daniel Mietchen5, Eric Prud’hommeaux6, and Andra Waagmeester7 1 Yale University, New Haven, CT, USA [email protected] 2 Johns Hopkins University, Baltimore, MD, USA [email protected] 3 The Scripps Research Institute, San Diego, CA, USA [email protected] 4 University of Oviedo, Oviedo, Spain [email protected] 5 Data Science Institute, University of Virginia, Charlottesville, VA, USA [email protected] 6 World Wide Web Consortium (W3C), MIT, Cambridge, MA, USA [email protected] 7 Micelio, Antwerpen, Belgium [email protected] Abstract. We discuss Shape Expressions (ShEx), a concise, formal, modeling and validation language for RDF structures. For instance, a Shape Expression could prescribe that subjects in a given RDF graph that fall into the shape “Paper” are expected to have a section called “Abstract”, and any ShEx implementation can confirm whether that is indeed the case for all such subjects within a given graph or subgraph. There are currently five actively maintained ShEx implementations. We discuss how we use the JavaScript, Scala and Python implementa- tions in RDF data validation workflows in distinct, applied contexts. We present examples of how ShEx can be used to model and validate data from two different sources, the domain-specific Fast Healthcare Interop- erability Resources (FHIR) and the domain-generic Wikidata knowledge base, which is the linked database built and maintained by the Wikimedia Foundation as a sister project to Wikipedia.
    [Show full text]
  • Browsing the Semantic Web
    Browsing the Semantic Web Ora Lassila Nokia Research Center Cambridge Cambridge, MA 02142, USA Abstract lution. Enabling browsing is further encouraged by the fact that, despite its simple data model, users and developers are Presenting RDF graphs to the end user as hypertext enables often put off by RDF’s cryptic XML-based syntax. interactive exploration and inquiry of “semantic” data. In Many tools have been constructed for searching, ex- this paper we present a tool that allows users to “see” their ploring and querying complex information spaces such as RDF data, without having to decipher syntactic represen- semistructured data representations or collections with rich tations that are typically not human-friendly. The tool is metadata. These tools often offer a mixture of features such part of a broader architecture designed for viewing many as faceted search, clustering of search results, etc. Exam- different types of data in Semantic Web formalisms, for ples of such systems include Lore [7, 8], Flamenco [26], experimenting with the caching of dynamically changing and others. More specifically, recent years have also seen a data, and for exploring the possible ad hoc integration of number of “Semantic Web browsers” emerge; examples of data from multiple sources. Additionally, this tool enables this type of software include mSpace [16], Haystack [18], browsing of semantic data on a mobile device, by adapting Magnet [23], DBin [25], semantExplorer [21], and others. the hypertext generation to better suit small screens. These systems allow the browsing of Semantic Web data and provide various ways of searching and visualizing this data. Many of them combine semantic data with “classi- 1.
    [Show full text]
  • An Introduction to RDF
    An Introduction to RDF Knowledge Technologies 1 Manolis Koubarakis Acknowledgement • This presentation is based on the excellent RDF primer by the W3C available at http://www.w3.org/TR/rdf-primer/ and http://www.w3.org/2007/02/turtle/primer/ . • Much of the material in this presentation is verbatim from the above Web site. Knowledge Technologies 2 Manolis Koubarakis Presentation Outline • Basic concepts of RDF • Serialization of RDF graphs: XML/RDF and Turtle • Other Features of RDF (Containers, Collections and Reification). Knowledge Technologies 3 Manolis Koubarakis What is RDF? •TheResource Description Framework (RDF) is a data model for representing information (especially metadata) about resources in the Web. • RDF can also be used to represent information about things that can be identified on the Web, even when they cannot be directly retrieved on the Web (e.g., a book or a person). • RDF is intended for situations in which information about Web resources needs to be processed by applications, rather than being only displayed to people. Knowledge Technologies 4 Manolis Koubarakis Some History • RDF draws upon ideas from knowledge representation, artificial intelligence, and data management, including: – Semantic networks –Frames – Conceptual graphs – Logic-based knowledge representation – Relational databases • Shameless self-promotion : The closest to RDF, pre-Web knowledge representation language is Telos: John Mylopoulos, Alexander Borgida, Matthias Jarke, Manolis Koubarakis: Telos: Representing Knowledge About Information Systems. ACM Trans. Inf. Syst. 8(4): 325-362 (1990). Knowledge Technologies 5 Manolis Koubarakis The Semantic Web “Layer Cake” Knowledge Technologies 6 Manolis Koubarakis RDF Basics • RDF is based on the idea of identifying resources using Web identifiers and describing resources in terms of simple properties and property values.
    [Show full text]
  • Application of Graph Databases for Static Code Analysis of Web-Applications
    Application of Graph Databases for Static Code Analysis of Web-Applications Daniil Sadyrin [0000-0001-5002-3639], Andrey Dergachev [0000-0002-1754-7120], Ivan Loginov [0000-0002-6254-6098], Iurii Korenkov [0000-0002-8948-2776], and Aglaya Ilina [0000-0003-1866-7914] ITMO University, Kronverkskiy prospekt, 49, St. Petersburg, 197101, Russia [email protected], [email protected], [email protected], [email protected], [email protected] Abstract. Graph databases offer a very flexible data model. We present the approach of static code analysis using graph databases. The main stage of the analysis algorithm is the construction of ASG (Abstract Source Graph), which represents relationships between AST (Abstract Syntax Tree) nodes. The ASG is saved to a graph database (like Neo4j) and queries to the database are made to get code properties for analysis. The approach is applied to detect and exploit Object Injection vulnerability in PHP web-applications. This vulnerability occurs when unsanitized user data enters PHP unserialize function. Successful exploitation of this vulnerability means building of “object chain”: a nested object, in the process of deserializing of it, a sequence of methods is being called leading to dangerous function call. In time of deserializing, some “magic” PHP methods (__wakeup or __destruct) are called on the object. To create the “object chain”, it’s necessary to analyze methods of classes declared in web-application, and find sequence of methods called from “magic” methods. The main idea of author’s approach is to save relationships between methods and functions in graph database and use queries to the database on Cypher language to find appropriate method calls.
    [Show full text]
  • Database Software Market: Billy Fitzsimmons +1 312 364 5112
    Equity Research Technology, Media, & Communications | Enterprise and Cloud Infrastructure March 22, 2019 Industry Report Jason Ader +1 617 235 7519 [email protected] Database Software Market: Billy Fitzsimmons +1 312 364 5112 The Long-Awaited Shake-up [email protected] Naji +1 212 245 6508 [email protected] Please refer to important disclosures on pages 70 and 71. Analyst certification is on page 70. William Blair or an affiliate does and seeks to do business with companies covered in its research reports. As a result, investors should be aware that the firm may have a conflict of interest that could affect the objectivity of this report. This report is not intended to provide personal investment advice. The opinions and recommendations here- in do not take into account individual client circumstances, objectives, or needs and are not intended as recommen- dations of particular securities, financial instruments, or strategies to particular clients. The recipient of this report must make its own independent decisions regarding any securities or financial instruments mentioned herein. William Blair Contents Key Findings ......................................................................................................................3 Introduction .......................................................................................................................5 Database Market History ...................................................................................................7 Market Definitions
    [Show full text]
  • Web and Semantic Web Query Languages: a Survey
    Web and Semantic Web Query Languages: A Survey James Bailey1, Fran¸coisBry2, Tim Furche2, and Sebastian Schaffert2 1 NICTA Victoria Laboratory Department of Computer Science and Software Engineering The University of Melbourne, Victoria 3010, Australia http://www.cs.mu.oz.au/~jbailey/ 2 Institute for Informatics,University of Munich, Oettingenstraße 67, 80538 M¨unchen, Germany http://pms.ifi.lmu.de/ Abstract. A number of techniques have been developed to facilitate powerful data retrieval on the Web and Semantic Web. Three categories of Web query languages can be distinguished, according to the format of the data they can retrieve: XML, RDF and Topic Maps. This ar- ticle introduces the spectrum of languages falling into these categories and summarises their salient aspects. The languages are introduced us- ing common sample data and query types. Key aspects of the query languages considered are stressed in a conclusion. 1 Introduction The Semantic Web Vision A major endeavour in current Web research is the so-called Semantic Web, a term coined by W3C founder Tim Berners-Lee in a Scientific American article describing the future of the Web [37]. The Semantic Web aims at enriching Web data (that is usually represented in (X)HTML or other XML formats) by meta-data and (meta-)data processing specifying the “meaning” of such data and allowing Web based systems to take advantage of “intelligent” reasoning capabilities. To quote Berners-Lee et al. [37]: “The Semantic Web will bring structure to the meaningful content of Web pages, creating an environment where software agents roaming from page to page can readily carry out sophisticated tasks for users.” The Semantic Web meta-data added to today’s Web can be seen as advanced semantic indices, making the Web into something rather like an encyclopedia.
    [Show full text]