Book Image

NoSQL Data Models

By : Olivier Pivert
Book Image

NoSQL Data Models

By: Olivier Pivert

Overview of this book

Big Data environments are now to be handled in most current applications, this book addresses the latest issues and hurdles that are encountered in such environments. The book begins by presenting an overview of NoSQL languages and systems. Then, you’ll evaluate SPARQL queries over large RDF datasets and devise a solution that will use the MapReduce framework to process SPARQL graph patterns. Next, you’ll handle the production of web data, generate a set of links between two different datasets and overcome different heterogeneity problems. Moving ahead, you’ll take the multi-graph based approach to overcome challenges faced by the RDF data management community. Finally, you’ll deal with the flexible querying of graph databases and textual data management. By the end of this book, you’ll have gathered essential information on big data challenges faced by NoSQL databases.
Table of Contents (11 chapters)
Preface
8
List of Authors
9
Index
10
End User License Agreement

3.3. Challenges of linking data

In previous sections, we have seen different methods which are proposed for the selection of candidate datasets for linking with a given (presumably yet unpublished) RDF graph. Provided that this task has been performed successfully, we now have at hand two RDF graphs to link, or else to discover the related entities across these two graphs. A relation of particular interest for the Semantic Web community is that of identity, given by the OWL predicate owl: sameAs. However, a given real-world entity may be described differently or even with complementary information in different data sources. Hence, the automatic discovery of identity links may become particularly difficult considering the heterogeneity of data on the Web. In this section, we focus on a number of real-world issues that may arise when comparing resources across datasets, and we illustrate these issues by the means of a fictional example given in Figure 3.3.

Let us imagine that the composer...