RDB2RDF Working Group Charter

Revised February 24, 2009

In the last few years there has been increasing interest in mapping Relational data to the Semantic Web. This is to allow Relational data to be combined with other data on the Web, to add semantics to Relational data and to aid in enterprise data integration. In October 2007, the W3C organized a workshop on RDF Access to Relational Databases. This led to the formation of the RDB2RDF Incubator Group to explore the area. This Incubator Group recently concluded its work and produced two deliverables: a Survey of the State of the Art and a RDB2RDF XG Final Report. The RDB2RDF XG Final Report. recommends that the W3C initiate a Working Group to standardize a language for mapping Relational database schemas to RDF and OWL. This charter is a follow-up to that recommendation.

Consequently, the mission of the RDB2RDF Working Group, part of the Semantic Web Activity, is to standardize a language for mapping Relational Database schemas into RDF and OWL: the RDB2RDF Mapping Language (R2RML).

The mapping language defined by the WG would facilitate the development of several types of products. It could be used to translate Relational data into RDF which could be stored in a triple store. This is sometimes called Extract-Transform-Load (ETL). Or it could be used to generate a virtual mapping that could be queried using SPARQL and the SPARQL translated to SQL queries on the underlying Relational data. Other products could be layered on top of these capabilities to query and deliver data in different ways as well as to integrate the data with other kinds of information on the Semantic Web. The RDB2RDF XG Final Report includes several detailed usecases that motivate the mapping language.

Join the RDB2RDF Working Group.

End date30 June 2011 (two years from inception)
ConfidentialityProceedings are public
Initial ChairsCHAIR INFO
Initial Team Contacts
(FTE %: 5 to 10)
Usual Meeting ScheduleTeleconferences: Weekly
Face-to-face: 3-4 per year


Based on the Survey of Current Approaches for Mapping of Relational Databases to RDF prepared by the RDB2RDF XG and the RDB2RDF XG Final Report the scope of R2RML is defined as follows:

The Survey of the State of the Art describes several languages and implementations that may be used as starting points for the work of the WG.

Success Criteria

Out of Scope


[Recommended information]

Other Deliverables

[Replace this text] Describe any other deliverables such as test suites, tools, or reviews of other groups' deliverables.


[Replace this text] Specification transition estimates and other milestones

Note: The group will document significant changes from this initial schedule on the group home page.
[Recommended information]

Timeline View Summary

[Replace this text] Put here a timeline view of all deliverables.


W3C Groups

SPARQL Working Group (DAWG)
Track the evolution of SPARQL (updates, etc.).
Define a dialect of RIF for the mapping language.
Track the evolution of OWL2.

Furthermore, RDB2RDF Working Group expects to follow these W3C Recommendations:

External Groups

Linked Data community
To support the implementation of the linked data principles.
The OKKAM Project
The ENS System for assigning reusable identifiers to people, locations, organizations, events, products, etc.
Neuro Commons Common Naming Project
Reusable identifiers for life sciences entities.
Health Care and Life Sciences Interest Group
Health Care and Life Sciences Interest Group


To be successful, the RDB2RDF Working Group is expected to have 5 or more active participants for its duration. Effective participation to RDB2RDF Working Group is expected to consume one work day per week for each participant; two days per week for editors. The RDB2RDF Working Group will allocate also the necessary resources for building Test Suites for each specification.

Participants are reminded of the Good Standing requirements of the W3C Process.


This group primarily conducts its work on the public mailing list LIST NAME. [Replace this text] Provide information about additional Member-only lists that are used for administrative purposes.

Information about the group (deliverables, participants, face-to-face meetings, teleconferences, etc.) is available from the RDB2RDF Working Group home page.

Decision Policy

As explained in the Process Document (section 3.3), this group will seek to make decisions when there is consensus. When the Chair puts a question and observes dissent, after due consideration of different opinions, the Chair should record a decision (possibly after a formal vote) and any objections, and move on.

Patent Policy

This Working Group operates under the W3C Patent Policy (5 February 2004 Version). To promote the widest adoption of Web standards, W3C seeks to issue Recommendations that can be implemented, according to this policy, on a Royalty-Free basis.

For more information about disclosure obligations for this group, please see the W3C Patent Policy Implementation.

About this Charter

This charter for the RDB2RDF Working Group has been created according to section 6.2 of the Process Document. In the event of a conflict between this document or the provisions of any charter and the W3C Process, the W3C Process shall take precedence.

Ashok Malhotra (Oracle), Michel Hausenblas (DERI)

$Date: 2009/02/24 23:13:35 $