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Virtuoso Linked Data Deployment In 3 Simple Steps

Injecting Linked Data into the Web has been a major pain point for those who seek personal, service, or organization-specific variants of DBpedia. Basically, the sequence goes something like this:

1. You encounter DBpedia or the LOD Cloud Pictorial.
2. You look around (typically following your nose from link to link).
3. You attempt to publish your own stuff.
4. You get stuck.

The problems typically take the following form:

1. Functionality confusion about the complementary Name and Address functionality of a single URI abstraction
2. Terminology confusion due to conflation and over-loading of terms such as Resource, URL, Representation, Document, etc.
3. Inability to find robust tools with which to generate Linked Data from existing data sources such as relational databases, CSV files, XML, Web Services, etc.

To start addressing these problems, here is a simple guide for generating and publishing Linked Data using Virtuoso.

Step 1 - RDF Data Generation

Existing RDF data can be added to the Virtuoso RDF Quad Store via a variety of built-in data loader utilities.

Many options allow you to easily and quickly generate RDF data from other data sources:

• Install the Sponger Bookmarklet for the URIBurner service. Bind this to your own SPARQL-compliant backend RDF database (in this scenario, your local Virtuoso instance), and then Sponge some HTTP-accessible resources.
• Convert relational DBMS data to RDF using the Virtuoso RDF Views Wizard.
• Starting with CSV files, you can
  • Place them at an HTTP-accessible location, and use the Virtuoso Sponger to convert them to RDF or;
  • Use the CVS import feature to import their content into Virtuoso's relational data engine; then use the built-in RDF Views Wizard as with other RDBMS data.
• Starting from XML files, you can
  • Use Virtuoso's inbuilt XSLT-Processor for manual XML to RDF/XML transformation or;
  • Leverage the Sponger Cartridge for GRDDL, if there is a transformation service associated with your XML data source, or;
  • Let the Sponger analyze the XML data source and make a best-effort transformation to RDF.

Step 2 - Linked Data Deployment

Install the Faceted Browser VAD package (fct_dav.vad) which delivers the following:

1. 
   Faceted Browser Engine UI


2. 
   Dynamic Hypermedia Resource Generator
   
   
   
   • delivers descriptor resources for every entity (data object) in the Native or Virtual Quad Stores
   
   
   • supports a broad array of output formats, including HTML+RDFa, RDF/XML, N3/Turtle, NTriples, RDF-JSON, OData+Atom, and OData+JSON.
     
   
   
   
   

Step 3 - Linked Data Consumption & Exploitation

Three simple steps allow you, your enterprise, and your customers to consume and exploit your newly deployed Linked Data --

1. 
   Load a page like this in your browser: http://<cname>[:<port>]/describe/?uri=<entity-uri>
   
   
   
   • 
     <cname>[:<port>] gets replaced by the host and port of your Virtuoso instance
   
   
   • 
     <entity-uri> gets replaced by the URI you want to see described -- for instance, the URI of one of the resources you let the Sponger handle.
     
   
   
   
   


2. 
   Follow the links presented in the descriptor page.
   


3. If you ever see a blank page with a hyperlink subject name in the About: section at the top of the page, simply add the parameter "&sp=1" to the URL in the browser's Address box, and hit [ENTER]. This will result in an "on the fly" resource retrieval, transformation, and descriptor page generation.


4. 
   Use the navigator controls to page up and down the data associated with the "in scope" resource descriptor.
   

Related

• 
  Sample Descriptor Page (what you see post completion of the steps in this post)
  


• 
  What is Linked Data, really?
  


• 
  Painless Linked Data Generation via URIBurner
  


• 
  How To Load RDF Data Into Virtuoso (various methods)


• 
  Virtuoso Bulk Loader Script for RDF
  


• 
  Bulk Loader Script for CSV
  


• 
  Wizard based generation of RDF based Linked Data from ODBC accessible Relational Databases
  

webservicesatomrdfxmlxsltodbcsqllinked_datasemanticwebsparqlhowtovirtuosoDataSpace

Virtuoso Linked Data Deployment 3-Step

Injecting Linked Data into the Web has been a major pain point for those who seek personal, service, or organization-specific variants of DBpedia. Basically, the sequence goes something like this:

1. You encounter DBpedia or the LOD Cloud Pictorial.
2. You look around (typically following your nose from link to link).
3. You attempt to publish your own stuff.
4. You get stuck.

The problems typically take the following form:

1. Functionality confusion about the complementary Name and Address functionality of a single URI abstraction
2. Terminology confusion due to conflation and over-loading of terms such as Resource, URL, Representation, Document, etc.
3. Inability to find robust tools with which to generate Linked Data from existing data sources such as relational databases, CSV files, XML, Web Services, etc.

To start addressing these problems, here is a simple guide for generating and publishing Linked Data using Virtuoso.

RDF Data Generation

Existing RDF data can be added to the Virtuoso RDF Quad Store via a variety of built-in data loader utilities.

Many options allow you to easily and quickly generate RDF data from other data sources:

• Install the Sponger Bookmarklet for the URIBurner service. Bind this to your own SPARQL-compliant backend RDF database (in this scenario, your local Virtuoso instance), and then Sponge some HTTP-accessible resources.
• Convert relational DBMS data to RDF using the Virtuoso RDF Views Wizard.
• Starting with CSV files, you can
  • Place them at an HTTP-accessible location, and use the Virtuoso Sponger to convert them to RDF or;
  • Use the CVS import feature to import their content into Virtuoso's relational data engine; then use the built-in RDF Views Wizard as with other RDBMS data.
• Starting from XML files, you can
  • Use Virtuoso's inbuilt XSLT-Processor for manual XML to RDF/XML transformation or;
  • Leverage the Sponger Cartridge for GRDDL, if there is a transformation service associated with your XML data source, or;
  • Let the Sponger analyze the XML data source and make a best-effort transformation to RDF.

Linked Data Deployment

Install the Faceted Browser VAD package (fct_dav.vad) which delivers the following:

1. 
   Faceted Browser Engine UI


2. 
   Dynamic Hypermedia Resource Generator
   
   
   
   • delivers descriptor resources for every entity (data object) in the Native or Virtual Quad Stores
   
   
   • supports a broad array of output formats, including HTML+RDFa, RDF/XML, N3/Turtle, NTriples, RDF-JSON, OData+Atom, and OData+JSON.
     
   
   
   
   

Linked Data Consumption & Exploitation

Three simple steps allow you, your enterprise, and your customers to consume and exploit your newly deployed Linked Data --

1. 
   Load a page like this in your browser: http://<cname>[:<port>]/describe/?uri=<entity-uri>
   
   
   
   • 
     <cname>[:<port>] gets replaced by the host and port of your Virtuoso instance
   
   
   • 
     <entity-uri> gets replaced by the URI you want to see described -- for instance, the URI of one of the resources you let the Sponger handle.
     
   
   
   
   


2. 
   Follow the links presented in the descriptor page.
   


3. If you ever see a blank page with a hyperlink subject name in the About: section at the top of the page, simply add the parameter "&sp=1" to the URL in the browser's Address box, and hit [ENTER]. This will result in an "on the fly" resource retrieval, transformation, and descriptor page generation.


4. 
   Use the navigator controls to page up and down the data associated with the "in scope" resource descriptor.
   

Related

• 
  Sample Descriptor Page (what you see post completion of the steps in this post)
  


• 
  What is Linked Data, really?
  


• 
  Painless Linked Data Generation via URIBurner
  


• 
  How To Load RDF Data Into Virtuoso (various methods)


• 
  Virtuoso Bulk Loader Script for RDF
  


• 
  Bulk Loader Script for CSV
  


• 
  Wizard based generation of RDF based Linked Data from ODBC accessible Relational Databases
  

webservicesatomrdfxmlxsltodbcsqllinked_datasemanticwebsparqlhowtovirtuosoDataSpace

What is Linked Data, really?

Linked Data is simply hypermedia-based structured data.

Linked Data offers everyone a Web-scale, Enterprise-grade mechanism for platform-independent creation, curation, access, and integration of data.

The fundamental steps to creating Linked Data are as follows:

1. Choose a Name Reference Mechanism — i.e., URIs.

2. 
   

   Choose a Data Model with which to Structure your Data — minimally, you need a model which clearly distinguishes

   
   
   
   
   1. 
      Subjects (also known as Entities)
   
   
   2. 
      Subject Attributes (also known as Entity Attributes), and
   
   
   3. 
      Attribute Values (also known as Subject Attribute Values or Entity Attribute Values).
   
   
   
   
3. 
   

   Choose one or more Data Representation Syntaxes (also called Markup Languages or Data Formats) to use when creating Resources with Content based on your chosen Data Model. Some Syntaxes in common use today are HTML+RDFa, N3, Turtle, RDF/XML, TriX, XRDS, GData, OData, OpenGraph, and many others.

   
   
4. 
   

   Choose a URI Scheme that facilitates binding Referenced Names to the Resources which will carry your Content -- your Structured Data.
   

   
   
5. 
   

   Create Structured Data by using your chosen Name Reference Mechanism, your chosen Data Model, and your chosen Data Representation Syntax, as follows:

   1. Identify Subject(s) using Resolvable URI(s).
   2. Identify Subject Attribute(s) using Resolvable URI(s).
   3. Assign Attribute Values to Subject Attributes. These Values may be either Literals (e.g., STRINGs, BLOBs) or Resolvable URIs.

You can create Linked Data (hypermedia-based data representations) Resources from or for many things. Examples include: personal profiles, calendars, address books, blogs, photo albums; there are many, many more.

Related

1. Linked Data an Introduction -- simple introduction to Linked Data and its virtues
2. How Data Makes Corporations Dumb -- Jeff Jonas (IBM) interview
3. Hypermedia Types -- evolving information portal covering different aspects of Hypermedia resource types
4. URIBurner -- service that generates Linked Data from a plethora of heterogeneous data sources
5. Linked Data Meme -- TimbL design issues note about Linked Data
6. Data 3.0 Manifesto -- note about format agnostic Linked Data
7. DBpedia -- large Linked Data Hub
8. Linked Open Data Cloud -- collection of Linked Data Spaces
9. Linked Open Commerce Cloud -- commerce (clicks & mortar and/or clicks & clicks) oriented Linked Data Space
10. LOD Cloud Cache -- massive Linked Data Space hosting most of the LOD Cloud Datasets
11. LOD2 Initiative -- EU Co-Funded Project to develop global knowledge space from LOD
.

gdatardfxmllinked_datasemanticwebDataSpace

What is Linked Data, really?

Linked Data is simply hypermedia-based structured data.

Linked Data offers everyone a Web-scale, Enterprise-grade mechanism for platform-independent creation, curation, access, and integration of data.

The fundamental steps to creating Linked Data are as follows:

1. Choose a Name Reference Mechanism — i.e., URIs.

2. 
   

   Choose a Data Model with which to Structure your Data — minimally, you need a model which clearly distinguishes

   
   
   
   
   1. 
      Subjects (also known as Entities)
   
   
   2. 
      Subject Attributes (also known as Entity Attributes), and
   
   
   3. 
      Attribute Values (also known as Subject Attribute Values or Entity Attribute Values).
   
   
   
   
3. 
   

   Choose one or more Data Representation Syntaxes (also called Markup Languages or Data Formats) to use when creating Resources with Content based on your chosen Data Model. Some Syntaxes in common use today are HTML+RDFa, N3, Turtle, RDF/XML, TriX, XRDS, GData, and OData; there are many others.

   
   
4. 
   

   Choose a URI Scheme that facilitates binding Referenced Names to the Resources which will carry your Content -- your Structured Data.
   

   
   
5. 
   

   Create Structured Data by using your chosen Name Reference Mechanism, your chosen Data Model, and your chosen Data Representation Syntax, as follows:

   1. Identify Subject(s) using Resolvable URI(s).
   2. Identify Subject Attribute(s) using Resolvable URI(s).
   3. Assign Attribute Values to Subject Attributes. These Values may be either Literals (e.g., STRINGs, BLOBs) or Resolvable URIs.

You can create Linked Data (hypermedia-based data representations) Resources from or for many things. Examples include: personal profiles, calendars, address books, blogs, photo albums; there are many, many more.

Related

1. Hypermedia Types -- evolving information portal covering different aspects of Hypermedia resource types
2. URIBurner -- service that generates Linked Data from a plethora of heterogeneous data sources
3. Linked Data Meme -- TimbL design issues note about Linked Data
4. Data 3.0 Manifesto -- note about format agnostic Linked Data
5. DBpedia -- large Linked Data Hub
6. Linked Open Data Cloud -- collection of Linked Data Spaces
7. Linked Open Commerce Cloud -- commerce (clicks & mortar and/or clicks & clicks) oriented Linked Data Space
8. LOD Cloud Cache -- massive Linked Data Space hosting most of the LOD Cloud Datasets
9. LOD2 Initiative -- EU Co-Funded Project to develop global knowledge space from LOD
.

gdatardfxmllinked_datasemanticwebDataSpace