<commit_before>+++
title = "Bringing Relational Data into the Graph"
date = "2017-01-11"
categories = ["R2RML", "virtual graphs", "relational databases"]
author = "<NAME>"
+++

When Stardog is used to unify relational data sources, it facilitates powerful
query and data management features. This post introduces Stardog's _virtual
graph_ feature and explores how to access data from existing relational
sources.<!--more-->

Stardog--an enterprise data unification system--is based around the graph data
model because we believe it's uniquely well-suited due to its flexibility and
expressivity. We believe declarative reasoning is key due to its unique ability
to map data and preserve consistency.

## Mapping and R2RML

Traditional data integration tools are based on the relational data model and
employ vendor-specific mapping languages and methods. The difficulty arises when
combining several sources which were modeled differently and conform to
independent sets of rules and constraints. First, a single shared data model
must represent a global view over the sources. Second, significant manipulation
and cleansing are typically required to transform between the source and target
schema as well as make the source data conform to a set of standardized rules.

Stardog supports the standard [W3C R2RML](https://www.w3.org/TR/r2rml/) mapping
language for defining how data in a relational system maps to RDF graphs. In
addition, we've created
the [Stardog Mapping Syntax](http://docs.stardog.com/#_stardog_mapping_syntax)
to simplify the process of writing these mappings. Mappings of this sort specify<commit_msg>oops, accidentally pubd jess piece. adding draft=true to unpub<commit_after>+++
title = "Bringing Relational Data into the Graph"
date = "2017-01-11"
categories = ["R2RML", "virtual graphs", "relational databases"]
author = "<NAME>"
draft = true
+++

When Stardog is used to unify relational data sources, it facilitates powerful
query and data management features. This post introduces Stardog's _virtual
graph_ feature and explores how to access data from existing relational
sources.<!--more-->

Stardog--an enterprise data unification system--is based around the graph data
model because we believe it's uniquely well-suited due to its flexibility and
expressivity. We believe declarative reasoning is key due to its unique ability
to map data and preserve consistency.

## Mapping and R2RML

Traditional data integration tools are based on the relational data model and
employ vendor-specific mapping languages and methods. The difficulty arises when
combining several sources which were modeled differently and conform to
independent sets of rules and constraints. First, a single shared data model
must represent a global view over the sources. Second, significant manipulation
and cleansing are typically required to transform between the source and target
schema as well as make the source data conform to a set of standardized rules.

Stardog supports the standard [W3C R2RML](https://www.w3.org/TR/r2rml/) mapping
language for defining how data in a relational system maps to RDF graphs. In
addition, we've created
the [Stardog Mapping Syntax](http://docs.stardog.com/#_stardog_mapping_syntax)
to simplify the process of writing these mappings. Mappings of this sort specify
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