Open Conceptual Data Models

Making the Conceptual Layer Real
HTTP based
Linked Data (aka. Linked Data)

Conceptual Data Models in the Linked Data Web

Linked Data Vision:

Concurrent trend in the IT industry:

The Big Question:

Open Conceptual Data Models


Data Model Layers

Logical Data Model


Logical Data Model Weaknesses

Impedance Mismatch

Conceptual level data model is desirable to:

Logical Data Model Weaknesses

Loss of Semantic Fidelity During Development



Logical Data Model Weaknesses

Heterogeneous Databases & Interoperability

Logical data model


Conceptual Models for Linked Data Webs

Explosion of User Generated Data from Web 2.0 applications and their Data Silos is driving the recognition of the need to move from logical to conceptual models, exemplified by:

Benefits of Conceptual Models

Application Areas - Present & Future

Semantic Web Project Technologies

These technologies offer:


Common Semantics (Ontologies) & Common Data Representation (RDF)

Open Data Formats, Platform Independence, Common Models

Realizing Conceptual Models


Describing Classes & Properties - Ontology Languages

Goodness of Fit

A natural fit!

RDF lends itself naturally to describing conceptual models

Semantic Expressivity Comparison

Data Definition Language (DDL)-based Relational Model

RDF-based Conceptual Model

RDF Conceptual Model - Artist / Records / Tracks

RDF Conceptual Model

Global Granular Information Sharing

Traditional Logical/Relational Data Model

RDF's use of Generic HTTP-based URIs

Linked Data - What is It?

A method for exposing, sharing & connecting data
on HTTP based Data Networks.

Linked Data - Why Is It Important

Linked Data Model

Changes the focus from linked documents to linked entities
The document as a data container becomes less relevant

Linked Data Model

Hyperdata Links Between Data Objects

Hyperdata Links Between Data Objects

Linked Data Benefits - Data Exploration

Natural Navigation Through Typed Links

Relational/Logical Model

Linked Data Benefits - Aggregatable Data

Often desirable to have an integrated view of all the data available about an item or topic

Database Realm

Semantic Web

Linked Data - Data Aggregation

Linked Data - Data Aggregation

Linked Data Benefits - Self Describing Data

Resource Description Framework (RDF)

Logical / Relational Schema

Linked Data Benefits - SPARQL

If a user agent has no built-in knowledge of a particular Data Item, it can dereference its Generic HTTP URI to obtain such information

The Power of SPARQL

Discover what sorts of things a data source contains

Determine all the properties of an data item's class

Determine all the properties and values of an data item instance

No prior knowledge of the RDF data source is needed

Virtuoso - Linked Data Generation Options

Conceptual layer insulates Linked Data consumers from RDFization infrastructure & data source heterogeneity

Virtuoso - Linked Data Generation Options

Virtuoso RDF based Linked Data Views

Northwind Demo Database: RDF View Definition Extract

Demo.demo.Customers: Demo.demo.Customers

Northwind RDF View Definition

prefix northwind: <>
create iri class northwind:Customer
 (in customer_id varchar not null)
alter quad storage virtrdf:DefaultQuadStorage
from Demo.demo.Customers as customers
from Demo.demo.Orders as orders ...{

create virtrdf:NorthwindDemo
 as graph iri ("http://^{URIQADefaultHost}^/Northwind") {
northwind:Customer(customers.CustomerID) a foaf:Organization
 as virtrdf:Customer-CustomerID ;
northwind:companyName customers.CompanyName as ... ;
northwind:fax customers.Fax as virtrdf:Customer-fax .

 northwind:has_order northwind:Order(orders.OrderID)
 as virtrdf:Order-has_order .
... }}

Northwind Demo Database: Customer Table to RDF data item Mapping

Customer Table to RDF Entity Mapping

Customer Table to RDF Entity Mapping Diagram

LinqToRdf + Virtuoso

LinqToRdf + Virtuoso

LinqToRdf to MusicBrainz - Conceptual Model Veneer

LinqToRdf to MusicBrainz - Conceptual Model Veneer

ADO.NET Data Services & Entity Data Model

A framework for exposing 'pure data' service over HTTP

No support for RDF

Lack of platform independence & standards compliance


ADO.NET Data Services & Entity Data Model

Server-side only conceptual model


Lack of Deferencable Entity IDs

c.f. SPARQL's ability to handle unknown data sources

ADO.NET Data Services & Entity Data Model

No Support for Non-SQL Data Sources

c.f. Linked Data

Astoria lacks scalability & scope of Semantic Web technologies