OpenLink Community Blog

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

What is URIBurner?

A service from OpenLink Software, available at: http://uriburner.com, that enables anyone to generate structured descriptions -on the fly- for resources that are already published to HTTP based networks. These descriptions exist as hypermedia resource representations where links are used to identify:

• the entity (data object or datum) being described,
• each of its attributes, and
• each of its attributes values (optionally).

The hypermedia resource representation outlined above is what is commonly known as an Entity-Attribute-Value (EAV) Graph. The use of generic HTTP scheme based Identifiers is what distinguishes this type of hypermedia resource from others.

Why is it Important?

The virtues (dual pronged serendipitous discovery) of publishing HTTP based Linked Data across public (World Wide Web) or private (Intranets and/or Extranets) is rapidly becoming clearer to everyone. That said, the nuance laced nature of Linked Data publishing presents significant challenges to most. Thus, for Linked Data to really blossom the process of publishing needs to be simplified i.e., "just click and go" (for human interaction) or REST-ful orchestration of HTTP CRUD (Create, Read, Update, Delete) operations between Client Applications and Linked Data Servers.

How Do I Use It?

In similar vane to the role played by FeedBurner with regards to Atom and RSS feed generation, during the early stages of the Blogosphere, it enables anyone to publish Linked Data bearing hypermedia resources on an HTTP network. Thus, its usage covers two profiles: Content Publisher and Content Consumer.

Content Publisher

The steps that follow cover all you need to do:

• place a tag within your HTTP based hypermedia resource (e.g. within section for HTML )
• use a URL via the @href attribute value to identify the location of the structured description of your resource, in this case it takes the form: http://linkeddata.uriburner.com/about/id/{scheme-or-protocol}/{your-hostname-or-authority}/{your-local-resource}
• for human visibility you may consider adding associating a button (as you do with Atom and RSS) with the URL above.

That's it! The discoverability (SDQ) of your content has just multiplied significantly, its structured description is now part of the Linked Data Cloud with a reference back to your site (which is now a bona fide HTTP based Linked Data Space).

Examples

HTML+RDFa based representation of a structured resource description:

<link rel="describedby" title="Resource Description (HTML)"type="text/html" href="http://linkeddata.uriburner.com/about/id/http/example.org/xyz.html"/>

JSON based representation of a structured resource description:

<link rel="describedby" title="Resource Description (JSON)" type="application/json" href="http://linkeddata.uriburner.com/about/id/http/example.org/xyz.html"/>

N3 based representation of a structured resource description:

<link rel="describedby" title="Resource Description (N3)" type="text/n3" href="http://linkeddata.uriburner.com/about/id/http/example.org/xyz.html"/>

RDF/XML based representations of a structured resource description:

<link rel="describedby" title="Resource Description (RDF/XML)" type="application/rdf+xml" href="http://linkeddata.uriburner.com/about/id/http/example.org/xyz.html"/>

Content Consumer

As an end-user, obtaining a structured description of any resource published to an HTTP network boils down to the following steps:

1. go to: http://uriburner.com
2. drag the Page Metadata Bookmarklet link to your Browser's toolbar
3. whenever you encounter a resource of interest (e.g. an HTML page) simply click on the Bookmarklet
4. you will be presented with an HTML representation of a structured resource description (i.e., identifier of the entity being described, its attributes, and its attribute values will be clearly presented).

Examples

• Description of a Book culled from an Amazon web page
• Description of a product offering culled from a BestBuy web page
• Description of a product (a camera) culled from a CNET web page
• Description of the same CNET product as an Offer on eBay (exposed by the description above via seeAlso property value).

If you are a developer, you can simply perform an HTTP operation request (from your development environment of choice) using any of the URL patterns presented below:

• curl -I -H "Accept: text/html" http://linkeddata.uriburner.com/about/id/{scheme}/{authority}/{local-path}

JSON:

• curl -I -H "Accept: application/json" http://linkeddata.uriburner.com/about/id/{scheme}/{authority}/{local-path}
• curl http://linkeddata.uriburner.com/about/data/json/{scheme}/{authority}/{local-path}

Notation 3 (N3):

• curl -I -H "Accept: text/n3" http://linkeddata.uriburner.com/about/id/{scheme}/{authority}/{local-path}
• curl http://linkeddata.uriburner.com/about/data/n3/{scheme}/{authority}/{local-path}

• curl -I -H "Accept: text/turtle" http://linkeddata.uriburner.com/about/id/{scheme}/{authority}/{local-path}
• curl http://linkeddata.uriburner.com/about/data/ttl/{scheme}/{authority}/{local-path}

RDF/XML:

• curl -I -H "Accept: application/rdf+xml" http://linkeddata.uriburner.com/about/id/{scheme}/{authority}/{local-path}
• curl http://linkeddata.uriburner.com/about/data/xml/{scheme}/{authority}/{local-path}

Conclusion

URIBurner is a "deceptively simple" solution for cost-effective exploitation of HTTP based Linked Data meshes. It doesn't require any programming or customization en route to immediately realizing its virtues.

If you like what URIBurner offers, but prefer to leverage its capabilities within your domain -- such that resource description URLs reside in your domain, all you have to do is perform the following steps:

1. download a copy of Virtuoso (for local desktop, workgroup, or data center installation) or
2. instantiate Virtuoso via the Amazon EC2 Cloud
3. enable the Sponger Middleware component via the RDF Mapper VAD package (which includes cartridges for over 30 different resources types)

When you install your own URIBurner instances, you also have the ability to perform customizations that increase resource description fidelity in line with your specific needs. All you need to do is develop a custom extractor cartridge and/or meta cartridge.

Related:

• Virtuoso Sponger Middleware -- (technology behind URIBurner Service)
• Animation demonstrating how the Virtuoso Sponger works.

What is URIBurner?

A service from OpenLink Software, available at: http://uriburner.com, that enables anyone to generate structured descriptions -on the fly- for resources that are already published to HTTP based networks. These descriptions exist as hypermedia resource representations where links are used to identify:

• the entity (data object or datum) being described,
• each of its attributes, and
• each of its attributes values (optionally).

The hypermedia resource representation outlined above is what is commonly known as an Entity-Attribute-Value (EAV) Graph. The use of generic HTTP scheme based Identifiers is what distinguishes this type of hypermedia resource from others.

Why is it Important?

The virtues (dual pronged serendipitous discovery) of publishing HTTP based Linked Data across public (World Wide Web) or private (Intranets and/or Extranets) is rapidly becoming clearer to everyone. That said, the nuance laced nature of Linked Data publishing presents significant challenges to most. Thus, for Linked Data to really blossom the process of publishing needs to be simplified i.e., "just click and go" (for human interaction) or REST-ful orchestration of HTTP CRUD (Create, Read, Update, Delete) operations between Client Applications and Linked Data Servers.

How Do I Use It?

In similar vane to the role played by FeedBurner with regards to Atom and RSS feed generation, during the early stages of the Blogosphere, it enables anyone to publish Linked Data bearing hypermedia resources on an HTTP network. Thus, its usage covers two profiles: Content Publisher and Content Consumer.

Content Publisher

The steps that follow cover all you need to do:

• place a tag within your HTTP based hypermedia resource (e.g. within section for HTML )
• use a URL via the @href attribute value to identify the location of the structured description of your resource, in this case it takes the form: http://linkeddata.uriburner.com/about/id/{scheme-or-protocol}/{your-hostname-or-authority}/{your-local-resource}
• for human visibility you may consider adding associating a button (as you do with Atom and RSS) with the URL above.

That's it! The discoverability (SDQ) of your content has just multiplied significantly, its structured description is now part of the Linked Data Cloud with a reference back to your site (which is now a bona fide HTTP based Linked Data Space).

Examples

HTML+RDFa based representation of a structured resource description:

<link rel="describedby" title="Resource Description (HTML)"type="text/html" href="http://linkeddata.uriburner.com/about/id/http/example.org/xyz.html"/>

JSON based representation of a structured resource description:

<link rel="describedby" title="Resource Description (JSON)" type="application/json" href="http://linkeddata.uriburner.com/about/id/http/example.org/xyz.html"/>

N3 based representation of a structured resource description:

<link rel="describedby" title="Resource Description (N3)" type="text/n3" href="http://linkeddata.uriburner.com/about/id/http/example.org/xyz.html"/>

RDF/XML based representations of a structured resource description:

<link rel="describedby" title="Resource Description (RDF/XML)" type="application/rdf+xml" href="http://linkeddata.uriburner.com/about/id/http/example.org/xyz.html"/>

Content Consumer

As an end-user, obtaining a structured description of any resource published to an HTTP network boils down to the following steps:

1. go to: http://uriburner.com
2. drag the Page Metadata Bookmarklet link to your Browser's toolbar
3. whenever you encounter a resource of interest (e.g. an HTML page) simply click on the Bookmarklet
4. you will be presented with an HTML representation of a structured resource description (i.e., identifier of the entity being described, its attributes, and its attribute values will be clearly presented).

Examples

• Description of a Book culled from an Amazon web page
• Description of a product offering culled from a BestBuy web page
• Description of a product (a camera) culled from a CNET web page
• Description of the same CNET product as an Offer on eBay (exposed by the description above via seeAlso property value).

If you are a developer, you can simply perform an HTTP operation request (from your development environment of choice) using any of the URL patterns presented below:

• curl -I -H "Accept: text/html" http://linkeddata.uriburner.com/about/id/{scheme}/{authority}/{local-path}

JSON:

• curl -I -H "Accept: application/json" http://linkeddata.uriburner.com/about/id/{scheme}/{authority}/{local-path}
• curl http://linkeddata.uriburner.com/about/data/json/{scheme}/{authority}/{local-path}

Notation 3 (N3):

• curl -I -H "Accept: text/n3" http://linkeddata.uriburner.com/about/id/{scheme}/{authority}/{local-path}
• curl http://linkeddata.uriburner.com/about/data/n3/{scheme}/{authority}/{local-path}

• curl -I -H "Accept: text/turtle" http://linkeddata.uriburner.com/about/id/{scheme}/{authority}/{local-path}
• curl http://linkeddata.uriburner.com/about/data/ttl/{scheme}/{authority}/{local-path}

RDF/XML:

• curl -I -H "Accept: application/rdf+xml" http://linkeddata.uriburner.com/about/id/{scheme}/{authority}/{local-path}
• curl http://linkeddata.uriburner.com/about/data/xml/{scheme}/{authority}/{local-path}

Conclusion

URIBurner is a "deceptively simple" solution for cost-effective exploitation of HTTP based Linked Data meshes. It doesn't require any programming or customization en route to immediately realizing its virtues.

If you like what URIBurner offers, but prefer to leverage its capabilities within your domain -- such that resource description URLs reside in your domain, all you have to do is perform the following steps:

1. download a copy of Virtuoso (for local desktop, workgroup, or data center installation) or
2. instantiate Virtuoso via the Amazon EC2 Cloud
3. enable the Sponger Middleware component via the RDF Mapper VAD package (which includes cartridges for over 30 different resources types)

When you install your own URIBurner instances, you also have the ability to perform customizations that increase resource description fidelity in line with your specific needs. All you need to do is develop a custom extractor cartridge and/or meta cartridge.

Related:

• Virtuoso Sponger Middleware -- (technology behind URIBurner Service)
• Animation demonstrating how the Virtuoso Sponger works.

Motivation for this post arose from a series of Twitter exchanges between Tony Hirst and I, in relation to his blog post titled: So What Is It About Linked Data that Makes it Linked Data™ ?

At the end of the marathon session, it was clear to me that a blog post was required for future reference, at the very least :-)

What is Linked Data?

"Data Access by Reference" mechanism for Data Objects (or Entities) on HTTP networks. It enables you to Identify a Data Object and Access its structured Data Representation via a single Generic HTTP scheme based Identifier (HTTP URI). Data Object representation formats may vary; but in all cases, they are hypermedia oriented, fully structured, and negotiable within the context of a client-server message exchange.

Why is it Important?

Information makes the world tick!

Information doesn't exist without data to contextualize.

Information is inaccessible without a projection (presentation) medium.

All information (without exception, when produced by humans) is subjective. Thus, to truly maximize the innate heterogeneity of collective human intelligence, loose coupling of our information and associated data sources is imperative.

How is Linked Data Delivered?

Linked Data is exposed to HTTP networks (e.g. World Wide Web) via hypermedia resources bearing structured representations of data object descriptions. Remember, you have a single Identifier abstraction (generic HTTP URI) that embodies: Data Object Name and Data Representation Location (aka URL).

How are Linked Data Object Representations Structured?

A structured representation of data exists when an Entity (Datum), its Attributes, and its Attribute Values are clearly discernible. In the case of a Linked Data Object, structured descriptions take the form of a hypermedia based Entity-Attribute-Value (EAV) graph pictorial -- where each Entity, its Attributes, and its Attribute Values (optionally) are identified using Generic HTTP URIs.

Examples of structured data representation formats (content types) associated with Linked Data Objects include:

• text/html
• text/turtle
• text/n3
• application/json
• application/rdf+xml
• Others

How Do I Create Linked Data oriented Hypermedia Resources?

You markup resources by expressing distinct entity-attribute-value statements (basically these a 3-tuple records) using a variety of notations:

• (X)HTML+RDFa,
• JSON,
• Turtle,
• N3,
• TriX,
• TriG,
• RDF/XML, and
• Others (for instance you can use Atom data format extensions to model EAV graph as per OData initiative from Microsoft).

You can achieve this task using any of the following approaches:

• Notepad
• WYSIWYG Editor
• Transformation of Database Records via Middleware
• Transformation of XML based Web Services output via Middleware
• Transformation of other Hypermedia Resources via Middleware
• Transformation of non Hypermedia Resources via Middleware
• Use a platform that delivers all of the above.

Practical Examples of Linked Data Objects Enable

• Describe Who You Are, What You Offer, and What You Need via your structured profile, then leave your HTTP network to perform the REST (serendipitous discovery of relevant things)
• Identify (via map overlay) all items of interest based on a 2km+ radious of my current location (this could include vendor offerings or services sought by existing or future customers)
• Share the latest and greatest family photos with family members *only* without forcing them to signup for Yet Another Web 2.0 service or Social Network
• No repetitive signup and username and password based login sequences per Web 2.0 or Mobile Application combo
• Going beyond imprecise Keyword Search to the new frontier of Precision Find - Example, Find Data Objects associated with the keywords: Tiger, while enabling the seeker disambiguate across the "Who", "What", "Where", "When" dimensions (with negation capability)
• Determine how two Data Objects are Connected - person to person, person to subject matter etc. (LinkedIn outside the walled garden)
• Use any resource address (e.g blog or bookmark URL) as the conduit into a Data Object mesh that exposes all associated Entities and their social network relationships
• Apply patterns (social dimensions) above to traditional enterprise data sources in combination (optionally) with external data without compromising security etc.

How Do OpenLink Software Products Enable Linked Data Exploitation?

Our data access middleware heritage (which spans 16+ years) has enabled us to assemble a rich portfolio of coherently integrated products that enable cost-effective evaluation and utilization of Linked Data, without writing a single line of code, or exposing you to the hidden, but extensive admin and configuration costs. Post installation, the benefits of Linked Data simply materialize (along the lines described above).

Our main Linked Data oriented products include:

• OpenLink Data Explorer -- visualizes Linked Data or Linked Data transformed "on the fly" from hypermedia and non hypermedia data sources
• URIBurner -- a "deceptively simple" solution that enables the generation of Linked Data "on the fly" from a broad collection of data sources and resource types
• OpenLink Data Spaces -- a platform for enterprises and individuals that enhances distributed collaboration via Linked Data driven virtualization of data across its native and/or 3rd party content manager for: Blogs, Wikis, Shared Bookmarks, Discussion Forums, Social Networks etc
• OpenLink Virtuoso -- a secure and high-performance native hybrid data server (Relational, RDF-Graph, Document models) that includes in-built Linked Data transformation middleware (aka. Sponger).

Related

• Hypertext Transfer Protocol 1.1 RFC
• Open Data Protocol Glossary
• Simple Explanation of RDF and Linked Data Dynamics
• Collection of post from the past about Linked Data
• Are We There Yet Re. Web++? -- includes link to podcast conversation with Jon Udell
• Web of Linked Data Pivoting Demo from TED -- by Microsoft's Gary Flake
• Microsoft Pivot atop Virtuoso Quad Store's Faceted Browser Engine-- My Demonstration of EAV model transcending data representation variations (i.e., RDF's EAV data model data served up in Microsoft CXML data representation format).

Motivation for this post arose from a series of Twitter exchanges between Tony Hirst and I, in relation to his blog post titled: So What Is It About Linked Data that Makes it Linked Data™ ?

At the end of the marathon session, it was clear to me that a blog post was required for future reference, at the very least :-)

What is Linked Data?

"Data Access by Reference" mechanism for Data Objects (or Entities) on HTTP networks. It enables you to Identify a Data Object and Access its structured Data Representation via a single Generic HTTP scheme based Identifier (HTTP URI). Data Object representation formats may vary; but in all cases, they are hypermedia oriented, fully structured, and negotiable within the context of a client-server message exchange.

Why is it Important?

Information makes the world tick!

Information doesn't exist without data to contextualize.

Information is inaccessible without a projection (presentation) medium.

All information (without exception, when produced by humans) is subjective. Thus, to truly maximize the innate heterogeneity of collective human intelligence, loose coupling of our information and associated data sources is imperative.

How is Linked Data Delivered?

Linked Data is exposed to HTTP networks (e.g. World Wide Web) via hypermedia resources bearing structured representations of data object descriptions. Remember, you have a single Identifier abstraction (generic HTTP URI) that embodies: Data Object Name and Data Representation Location (aka URL).

How are Linked Data Object Representations Structured?

A structured representation of data exists when an Entity (Datum), its Attributes, and its Attribute Values are clearly discernible. In the case of a Linked Data Object, structured descriptions take the form of a hypermedia based Entity-Attribute-Value (EAV) graph pictorial -- where each Entity, its Attributes, and its Attribute Values (optionally) are identified using Generic HTTP URIs.

Examples of structured data representation formats (content types) associated with Linked Data Objects include:

• text/html
• text/turtle
• text/n3
• application/json
• application/rdf+xml
• Others

How Do I Create Linked Data oriented Hypermedia Resources?

You markup resources by expressing distinct entity-attribute-value statements (basically these a 3-tuple records) using a variety of notations:

• (X)HTML+RDFa,
• JSON,
• Turtle,
• N3,
• TriX,
• TriG,
• RDF/XML, and
• Others (for instance you can use Atom data format extensions to model EAV graph as per OData initiative from Microsoft).

You can achieve this task using any of the following approaches:

• Notepad
• WYSIWYG Editor
• Transformation of Database Records via Middleware
• Transformation of XML based Web Services output via Middleware
• Transformation of other Hypermedia Resources via Middleware
• Transformation of non Hypermedia Resources via Middleware
• Use a platform that delivers all of the above.

Practical Examples of Linked Data Objects Enable

• Describe Who You Are, What You Offer, and What You Need via your structured profile, then leave your HTTP network to perform the REST (serendipitous discovery of relevant things)
• Identify (via map overlay) all items of interest based on a 2km+ radious of my current location (this could include vendor offerings or services sought by existing or future customers)
• Share the latest and greatest family photos with family members *only* without forcing them to signup for Yet Another Web 2.0 service or Social Network
• No repetitive signup and username and password based login sequences per Web 2.0 or Mobile Application combo
• Going beyond imprecise Keyword Search to the new frontier of Precision Find - Example, Find Data Objects associated with the keywords: Tiger, while enabling the seeker disambiguate across the "Who", "What", "Where", "When" dimensions (with negation capability)
• Determine how two Data Objects are Connected - person to person, person to subject matter etc. (LinkedIn outside the walled garden)
• Use any resource address (e.g blog or bookmark URL) as the conduit into a Data Object mesh that exposes all associated Entities and their social network relationships
• Apply patterns (social dimensions) above to traditional enterprise data sources in combination (optionally) with external data without compromising security etc.

How Do OpenLink Software Products Enable Linked Data Exploitation?

Our data access middleware heritage (which spans 16+ years) has enabled us to assemble a rich portfolio of coherently integrated products that enable cost-effective evaluation and utilization of Linked Data, without writing a single line of code, or exposing you to the hidden, but extensive admin and configuration costs. Post installation, the benefits of Linked Data simply materialize (along the lines described above).

Our main Linked Data oriented products include:

• OpenLink Data Explorer -- visualizes Linked Data or Linked Data transformed "on the fly" from hypermedia and non hypermedia data sources
• URIBurner -- a "deceptively simple" solution that enables the generation of Linked Data "on the fly" from a broad collection of data sources and resource types
• OpenLink Data Spaces -- a platform for enterprises and individuals that enhances distributed collaboration via Linked Data driven virtualization of data across its native and/or 3rd party content manager for: Blogs, Wikis, Shared Bookmarks, Discussion Forums, Social Networks etc
• OpenLink Virtuoso -- a secure and high-performance native hybrid data server (Relational, RDF-Graph, Document models) that includes in-built Linked Data transformation middleware (aka. Sponger).

Related

• Hypertext Transfer Protocol 1.1 RFC
• Open Data Protocol Glossary
• Simple Explanation of RDF and Linked Data Dynamics
• Collection of post from the past about Linked Data
• Are We There Yet Re. Web++? -- includes link to podcast conversation with Jon Udell
• Web of Linked Data Pivoting Demo from TED -- by Microsoft's Gary Flake
• Microsoft Pivot atop Virtuoso Quad Store's Faceted Browser Engine-- My Demonstration of EAV model transcending data representation variations (i.e., RDF's EAV data model data served up in Microsoft CXML data representation format).

Motivation for this post arose from a series of Twitter exchanges between Tony Hirst and I, in relation to his blog post titled: So What Is It About Linked Data that Makes it Linked Data™ ?

At the end of the marathon session, it was clear to me that a blog post was required for future reference, at the very least :-)

What is Linked Data?

"Data Access by Reference" mechanism for Data Objects (or Entities) on HTTP networks. It enables you to Identify a Data Object and Access its structured Data Representation via a single Generic HTTP scheme based Identifier (HTTP URI). Data Object representation formats may vary; but in all cases, they are hypermedia oriented, fully structured, and negotiable within the context of a client-server message exchange.

Why is it Important?

Information makes the world tick!

Information doesn't exist without data to contextualize.

Information is inaccessible without a projection (presentation) medium.

All information (without exception, when produced by humans) is subjective. Thus, to truly maximize the innate heterogeneity of collective human intelligence, loose coupling of our information and associated data sources is imperative.

How is Linked Data Delivered?

Linked Data is exposed to HTTP networks (e.g. World Wide Web) via hypermedia resources bearing structured representations of data object descriptions. Remember, you have a single Identifier abstraction (generic HTTP URI) that embodies: Data Object Name and Data Representation Location (aka URL).

How are Linked Data Object Representations Structured?

A structured representation of data exists when an Entity (Datum), its Attributes, and its Attribute Values are clearly discernible. In the case of a Linked Data Object, structured descriptions take the form of a hypermedia based Entity-Attribute-Value (EAV) graph pictorial -- where each Entity, its Attributes, and its Attribute Values (optionally) are identified using Generic HTTP URIs.

Examples of structured data representation formats (content types) associated with Linked Data Objects include:

• text/html
• text/turtle
• text/n3
• application/json
• application/rdf+xml
• Others

How Do I Create Linked Data oriented Hypermedia Resources?

You markup resources by expressing distinct entity-attribute-value statements (basically these a 3-tuple records) using a variety of notations:

• (X)HTML+RDFa,
• JSON,
• Turtle,
• N3,
• TriX,
• TriG,
• RDF/XML, and
• Others (for instance you can use Atom data format extensions to model EAV graph as per OData initiative from Microsoft).

You can achieve this task using any of the following approaches:

• Notepad
• WYSIWYG Editor
• Transformation of Database Records via Middleware
• Transformation of XML based Web Services output via Middleware
• Transformation of other Hypermedia Resources via Middleware
• Transformation of non Hypermedia Resources via Middleware
• Use a platform that delivers all of the above.

Practical Examples of Linked Data Objects Enable

• Describe Who You Are, What You Offer, and What You Need via your structured profile, then leave your HTTP network to perform the REST (serendipitous discovery of relevant things)
• Identify (via map overlay) all items of interest based on a 2km+ radious of my current location (this could include vendor offerings or services sought by existing or future customers)
• Share the latest and greatest family photos with family members *only* without forcing them to signup for Yet Another Web 2.0 service or Social Network
• No repetitive signup and username and password based login sequences per Web 2.0 or Mobile Application combo
• Going beyond imprecise Keyword Search to the new frontier of Precision Find - Example, Find Data Objects associated with the keywords: Tiger, while enabling the seeker disambiguate across the "Who", "What", "Where", "When" dimensions (with negation capability)
• Determine how two Data Objects are Connected - person to person, person to subject matter etc. (LinkedIn outside the walled garden)
• Use any resource address (e.g blog or bookmark URL) as the conduit into a Data Object mesh that exposes all associated Entities and their social network relationships
• Apply patterns (social dimensions) above to traditional enterprise data sources in combination (optionally) with external data without compromising security etc.

How Do OpenLink Software Products Enable Linked Data Exploitation?

Our data access middleware heritage (which spans 16+ years) has enabled us to assemble a rich portfolio of coherently integrated products that enable cost-effective evaluation and utilization of Linked Data, without writing a single line of code, or exposing you to the hidden, but extensive admin and configuration costs. Post installation, the benefits of Linked Data simply materialize (along the lines described above).

Our main Linked Data oriented products include:

• OpenLink Data Explorer -- visualizes Linked Data or Linked Data transformed "on the fly" from hypermedia and non hypermedia data sources
• URIBurner -- a "deceptively simple" solution that enables the generation of Linked Data "on the fly" from a broad collection of data sources and resource types
• OpenLink Data Spaces -- a platform for enterprises and individuals that enhances distributed collaboration via Linked Data driven virtualization of data across its native and/or 3rd party content manager for: Blogs, Wikis, Shared Bookmarks, Discussion Forums, Social Networks etc
• OpenLink Virtuoso -- a secure and high-performance native hybrid data server (Relational, RDF-Graph, Document models) that includes in-built Linked Data transformation middleware (aka. Sponger).

Related

• Hypertext Transfer Protocol 1.1 RFC
• Open Data Protocol Glossary
• Simple Explanation of RDF and Linked Data Dynamics
• Collection of post from the past about Linked Data
• Are We There Yet Re. Web++? -- includes link to podcast conversation with Jon Udell
• Web of Linked Data Pivoting Demo from TED -- by Microsoft's Gary Flake
• Microsoft Pivot atop Virtuoso Quad Store's Faceted Browser Engine-- My Demonstration of EAV model transcending data representation variations (i.e., RDF's EAV data model data served up in Microsoft CXML data representation format).

Motivation for this post arose from a series of Twitter exchanges between Tony Hirst and I, in relation to his blog post titled: So What Is It About Linked Data that Makes it Linked Data™ ?

At the end of the marathon session, it was clear to me that a blog post was required for future reference, at the very least :-)

What is Linked Data?

"Data Access by Reference" mechanism for Data Objects (or Entities) on HTTP networks. It enables you to Identify a Data Object and Access its structured Data Representation via a single Generic HTTP scheme based Identifier (HTTP URI). Data Object representation formats may vary; but in all cases, they are hypermedia oriented, fully structured, and negotiable within the context of a client-server message exchange.

Why is it Important?

Information makes the world tick!

Information doesn't exist without data to contextualize.

Information is inaccessible without a projection (presentation) medium.

All information (without exception, when produced by humans) is subjective. Thus, to truly maximize the innate heterogeneity of collective human intelligence, loose coupling of our information and associated data sources is imperative.

How is Linked Data Delivered?

Linked Data is exposed to HTTP networks (e.g. World Wide Web) via hypermedia resources bearing structured representations of data object descriptions. Remember, you have a single Identifier abstraction (generic HTTP URI) that embodies: Data Object Name and Data Representation Location (aka URL).

How are Linked Data Object Representations Structured?

A structured representation of data exists when an Entity (Datum), its Attributes, and its Attribute Values are clearly discernible. In the case of a Linked Data Object, structured descriptions take the form of a hypermedia based Entity-Attribute-Value (EAV) graph pictorial -- where each Entity, its Attributes, and its Attribute Values (optionally) are identified using Generic HTTP URIs.

Examples of structured data representation formats (content types) associated with Linked Data Objects include:

• text/html
• text/turtle
• text/n3
• application/json
• application/rdf+xml
• Others

How Do I Create Linked Data oriented Hypermedia Resources?

You markup resources by expressing distinct entity-attribute-value statements (basically these a 3-tuple records) using a variety of notations:

• (X)HTML+RDFa,
• JSON,
• Turtle,
• N3,
• TriX,
• TriG,
• RDF/XML, and
• Others (for instance you can use Atom data format extensions to model EAV graph as per OData initiative from Microsoft).

You can achieve this task using any of the following approaches:

• Notepad
• WYSIWYG Editor
• Transformation of Database Records via Middleware
• Transformation of XML based Web Services output via Middleware
• Transformation of other Hypermedia Resources via Middleware
• Transformation of non Hypermedia Resources via Middleware
• Use a platform that delivers all of the above.

Practical Examples of Linked Data Objects Enable

• Describe Who You Are, What You Offer, and What You Need via your structured profile, then leave your HTTP network to perform the REST (serendipitous discovery of relevant things)
• Identify (via map overlay) all items of interest based on a 2km+ radious of my current location (this could include vendor offerings or services sought by existing or future customers)
• Share the latest and greatest family photos with family members *only* without forcing them to signup for Yet Another Web 2.0 service or Social Network
• No repetitive signup and username and password based login sequences per Web 2.0 or Mobile Application combo
• Going beyond imprecise Keyword Search to the new frontier of Precision Find - Example, Find Data Objects associated with the keywords: Tiger, while enabling the seeker disambiguate across the "Who", "What", "Where", "When" dimensions (with negation capability)
• Determine how two Data Objects are Connected - person to person, person to subject matter etc. (LinkedIn outside the walled garden)
• Use any resource address (e.g blog or bookmark URL) as the conduit into a Data Object mesh that exposes all associated Entities and their social network relationships
• Apply patterns (social dimensions) above to traditional enterprise data sources in combination (optionally) with external data without compromising security etc.

How Do OpenLink Software Products Enable Linked Data Exploitation?

Our data access middleware heritage (which spans 16+ years) has enabled us to assemble a rich portfolio of coherently integrated products that enable cost-effective evaluation and utilization of Linked Data, without writing a single line of code, or exposing you to the hidden, but extensive admin and configuration costs. Post installation, the benefits of Linked Data simply materialize (along the lines described above).

Our main Linked Data oriented products include:

• OpenLink Data Explorer -- visualizes Linked Data or Linked Data transformed "on the fly" from hypermedia and non hypermedia data sources
• URIBurner -- a "deceptively simple" solution that enables the generation of Linked Data "on the fly" from a broad collection of data sources and resource types
• OpenLink Data Spaces -- a platform for enterprises and individuals that enhances distributed collaboration via Linked Data driven virtualization of data across its native and/or 3rd party content manager for: Blogs, Wikis, Shared Bookmarks, Discussion Forums, Social Networks etc
• OpenLink Virtuoso -- a secure and high-performance native hybrid data server (Relational, RDF-Graph, Document models) that includes in-built Linked Data transformation middleware (aka. Sponger).

Related

• Hypertext Transfer Protocol 1.1 RFC
• Open Data Protocol Glossary
• Simple Explanation of RDF and Linked Data Dynamics
• Collection of post from the past about Linked Data
• Are We There Yet Re. Web++? -- includes link to podcast conversation with Jon Udell
• Web of Linked Data Pivoting Demo from TED -- by Microsoft's Gary Flake
• Microsoft Pivot atop Virtuoso Quad Store's Faceted Browser Engine-- My Demonstration of EAV model transcending data representation variations (i.e., RDF's EAV data model data served up in Microsoft CXML data representation format).

Problem:

Your Life, Profession, Web, and Internet do not need to become mutually exclusive due to "information overload".

Solution:

A platform or service that delivers a point of online presence that embodies the fundamental separation of: Identity, Data Access, Data Representation, Data Presentation, by adhering to Web and Internet protocols.

How:

Typical post installation (Local or Cloud) task sequence:

1. Identify myself (happens automatically by way of registration)
2. If in an LDAP environment, import accounts or associate system with LDAP for account lookup and authentication
3. Identify Online Accounts (by fleshing out profile) which also connects system to online accounts and their data
4. Use Profile for granular description (Biography, Interests, WishList, OfferList, etc.)
5. Optionally upstream or downstream data to and from my online accounts
6. Create content Tagging Rules
7. Create rules for associating Tags with formal URIs
8. Create automatic Hyperlinking Rules for reuse when new content is created (e.g. Blog posts)
9. Exploit Data Portability virtues of RSS, Atom, OPML, RDFa, RDF/XML, and other formats for imports and exports
10. Automatically tag imported content
11. Use function-specific helper application UIs for domain specific data generation e.g. AddressBook (optionally use vCard import), Calendar (optionally use iCalendar import), Email, File Storage (use WebDAV mount with copy and paste or HTTP GET), Feed Subscriptions (optionally import RSS/Atom/OPML feeds), Bookmarking (optionally import bookmark.html or XBEL) etc..
12. Optionally enable "Conversation" feature (today: Social Media feature) across the relevant application domains (manage conversations under covers using NNTP, the standard for this functionality realm)
13. Generate HTTP based Entity IDs (URIs) for every piece of data in this burgeoning data space
14. Use REST based APIs to perform CRUD tasks against my data (local and remote) (SPARQL, GData, Ubiquity Commands, Atom Publishing)
15. Use OpenID, OAuth, FOAF+SSL, FOAF+SSL+OpenID for accessing data elsewhere
16. Use OpenID, OAuth, FOAF+SSL, FOAF+SSL+OpenID for Controlling access to my data (Self Signed Certificate Generation, Browser Import of said Certificate & associated Private Key, plus persistence of Certificate to FOAF based profile data space in "one click")
17. Have a simple UI for Entity-Attribute-Value or Subject-Predicate-Object arbitrary data annotations and creation since you can't pre model an "Open World" where the only constant is data flow
18. Have my Personal URI (Web ID) as the single entry point for controlled access to my HTTP accessible data space

I've just outlined a snippet of the capabilities of the OpenLink Data Spaces platform. A platform built using OpenLink Virtuoso, architected to deliver: open, platform independent, multi-model, data access and data management across heterogeneous data sources.

All you need to remember is your URI when seeking to interact with your data space.

Related

1. Get Yourself a URI (Web ID) in 5 Minutes or Less!
2. Various posts over the years about Data Spaces
3. Future of Desktop Post
4. Simplify My Life Post by Bengee Nowack

Problem:

Your Life, Profession, Web, and Internet do not need to become mutually exclusive due to "information overload".

Solution:

A platform or service that delivers a point of online presence that embodies the fundamental separation of: Identity, Data Access, Data Representation, Data Presentation, by adhering to Web and Internet protocols.

How:

Typical post installation (Local or Cloud) task sequence:

1. Identify myself (happens automatically by way of registration)
2. If in an LDAP environment, import accounts or associate system with LDAP for account lookup and authentication
3. Identify Online Accounts (by fleshing out profile) which also connects system to online accounts and their data
4. Use Profile for granular description (Biography, Interests, WishList, OfferList, etc.)
5. Optionally upstream or downstream data to and from my online accounts
6. Create content Tagging Rules
7. Create rules for associating Tags with formal URIs
8. Create automatic Hyperlinking Rules for reuse when new content is created (e.g. Blog posts)
9. Exploit Data Portability virtues of RSS, Atom, OPML, RDFa, RDF/XML, and other formats for imports and exports
10. Automatically tag imported content
11. Use function-specific helper application UIs for domain specific data generation e.g. AddressBook (optionally use vCard import), Calendar (optionally use iCalendar import), Email, File Storage (use WebDAV mount with copy and paste or HTTP GET), Feed Subscriptions (optionally import RSS/Atom/OPML feeds), Bookmarking (optionally import bookmark.html or XBEL) etc..
12. Optionally enable "Conversation" feature (today: Social Media feature) across the relevant application domains (manage conversations under covers using NNTP, the standard for this functionality realm)
13. Generate HTTP based Entity IDs (URIs) for every piece of data in this burgeoning data space
14. Use REST based APIs to perform CRUD tasks against my data (local and remote) (SPARQL, GData, Ubiquity Commands, Atom Publishing)
15. Use OpenID, OAuth, FOAF+SSL, FOAF+SSL+OpenID for accessing data elsewhere
16. Use OpenID, OAuth, FOAF+SSL, FOAF+SSL+OpenID for Controlling access to my data (Self Signed Certificate Generation, Browser Import of said Certificate & associated Private Key, plus persistence of Certificate to FOAF based profile data space in "one click")
17. Have a simple UI for Entity-Attribute-Value or Subject-Predicate-Object arbitrary data annotations and creation since you can't pre model an "Open World" where the only constant is data flow
18. Have my Personal URI (Web ID) as the single entry point for controlled access to my HTTP accessible data space

I've just outlined a snippet of the capabilities of the OpenLink Data Spaces platform. A platform built using OpenLink Virtuoso, architected to deliver: open, platform independent, multi-model, data access and data management across heterogeneous data sources.

All you need to remember is your URI when seeking to interact with your data space.

Related

1. Get Yourself a URI (Web ID) in 5 Minutes or Less!
2. Various posts over the years about Data Spaces
3. Future of Desktop Post
4. Simplify My Life Post by Bengee Nowack

What is it?

A pre-installed edition of Virtuoso for Amazon's EC2 Cloud platform.

What does it offer?

1. Low cost entry point to a game-changing Web 3.0+ (and beyond) platform that combines SQL, RDF, XML, and Web Services functionality
2. Flexible variable cost model (courtesy of EC2 DevPay) tightly bound to revenue generated by your services
3. Delivers federated and/or centralized model flexibility for you SaaS based solutions
4. Simple entry point for developing and deploying sophisticated database driven applications (SQL or RDF Linked Data Web oriented)
5. Complete framework for exploiting OpenID, OAuth (including Role enhancements) that simplifies exploitation of these vital Identity and Data Access technologies
6. Easily implement RDF Linked Data based Mail, Blogging, Wikis, Bookmarks, Calendaring, Discussion Forums, Tagging, Social-Networking as Data Space (data containers) features of your application or service offering
7. Instant alleviation of challenges (e.g. service costs and agility) associated with Data Portability and Open Data Access across Web 2.0 data silos
8. LDAP integration for Intranet / Extranet style applications.

From the DBMS engine perspective it provides you with one or more pre-configured instances of Virtuoso that enable immediate exploitation of the following services:

1. RDF Database (a Quad Store with SPARQL & SPARUL Language & Protocol support)
2. SQL Database (with ODBC, JDBC, OLE-DB, ADO.NET, and XMLA driver access)
3. XML Database (XML Schema, XQuery/Xpath, XSLT, Full Text Indexing)
4. Full Text Indexing.

From a Middleware perspective it provides:

1. RDF Views (Wrappers / Semantic Covers) over SQL, XML, and other data sources accessible via SOAP or REST style Web Services
2. Sponger Service for converting non RDF information resources into RDF Linked Data "on the fly" via a large collection of pre-installed RDFizer Cartridges.

From the Web Server Platform perspective it provides an alternative to LAMP stack components such as MySQL and Apace by offering

1. HTTP Web Server
2. WebDAV Server
3. Web Application Server (includes PHP runtime hosting)
4. SOAP or REST style Web Services Deployment
5. RDF Linked Data Deployment
6. SPARQL (SPARQL Query Language) and SPARUL (SPARQL Update Language) endpoints
7. Virtuoso Hosted PHP packages for MediaWiki, Drupal, Wordpress, and phpBB3 (just install the relevant Virtuoso Distro. Package).

From the general System Administrator's perspective it provides:

1. Online Backups (Backup Set dispatched to S3 buckets, FTP, or HTTP/WebDAV server locations)
2. Synchronized Incremental Backups to Backup Set locations
3. Backup Restore from Backup Set location (without exiting to EC2 shell).

Higher level user oriented offerings include:

1. OpenLink Data Explorer front-end for exploring the burgeoning Linked Data Web
2. Ajax based SPARQL Query Builder (iSPARQL) that enables SPARQL Query construction by Example
3. Ajax based SQL Query Builder (QBE) that enables SQL Query construction by Example.

For Web 2.0 / 3.0 users, developers, and entrepreneurs it offers it includes Distributed Collaboration Tools & Social Media realm functionality courtesy of ODS that includes:

1. Point of presence on the Linked Data Web that meshes your Identity and your Data via URIs
2. System generated Social Network Profile & Contact Data via FOAF?
3. System generated SIOC (Semantically Interconnected Online Community) Data Space (that includes a Social Graph) exposing all your Web data in RDF Linked Data form
4. System generated OpenID and automatic integration with FOAF
5. Transparent Data Integration across Facebook, Digg, LinkedIn, FriendFeed, Twitter, and any other Web 2.0 data space equipped with RSS / Atom support and/or REST style Web Services
6. In-built support for SyncML which enables data synchronization with Mobile Phones.

How Do I Get Going with It?

• Standard Installation Guide
• Personal or Service Specific DBpedia Installation Guide