W3C

SPARQL Working Group Charter

The mission of the SPARQL Working Group, part of the Semantic Web Activity, is to develop SPARQL, the query language for the Semantic Web. The scope of this charter is to extend SPARQL technology to include some of the features that the community has identified as both desirable and important for interoperability based on experience with the initial version of the standard.

Join the SPARQL Working Group.

End date 30 March 2013 (updated)
Confidentiality Proceedings are public
Chairs Lee Feigenbaum
Axel Polleres
Staff Contact Sandro Hawke (20%)
Usual Meeting Schedule Teleconferences: Weekly
Face-to-face: 1-2 per year

Background

Note: This June 2011 version of this charter differs only slightly from the 2009 version. The key change is that the JSON results format has been moved to the Recommendation Track. A possible CSV/TSV results format was also added. The schedule has also been updated, and various minor clarifications and improvements have been made. Details are listed in changes since 2009 and visible in the color-coded diff..

In January 2008, the RDF Data Access Working Group published three SPARQL recommendations (Query Language, Protocol, and Results Format). Since then, SPARQL has become very widely deployed. Usage and implementation of SPARQL have revealed requirements for additions to the query language and protocol that are needed by applications. Some of those were known during development of the first standard, but at the time there was insufficient experience to include them in the standard. Current implementation experience and feedback from the user community makes it now feasible to handle some of those issues in a satisfactory manner.

In February 2009, W3C renamed the group the "SPARQL Working Group" with a charter to enumerate the features expected to be included in the next revision of SPARQL, which it did by publishing SPARQL New Features and Rationale. See additional historical notes below.

Scope

The 2 July 2009 Working Draft of SPARQL New Features and Rationale establishes the scope of this charter (and includes more rationale than shown below).

Compatibility Expectation

For all new features, backwards compatibility with the current version of SPARQL is of great importance. All queries, that are valid in the January 2008 version of SPARQL, should remain valid in the new version and should produce identical results, except in the case of errata. For each new feature, if there is doubt or a perceived problem with respect to this, the guideline should be to not include the feature in the set of additions.

New Features

The group plans to specify the following features, grouped as follows:

  1. Additions to the SPARQL Query Language
  2. Service Description
  3. Update
  4. Entailment

The 2 July 2009 draft of SPARQL New Features and Rationale identifies two lists of features: "Required features" and "Time-permitting features". The former includes features whose inclusion in the final recommendations is required for the Working Group to successfully complete its charter, whereas the latter includes features that the Working Group intends to add to the final recommendation, but which may be abandoned if the Working Group has insufficient time or resources. Working Group members and the community are encouraged to develop the time-permitting features. The Working Group is expected to give priority in allocating resources to the required features until they are completed.

Additions to the SPARQL Query Language

Required features:

Time permitting:

Service Description

Required feature:

Update

Required features:

Entailment

Time permitting:

Deliverables

The group expects to publish the following documents consistent with the above scope. The titles of the documents are indicative only.

Some of the new features might be published as separate documents that would not be necessarily part of the “Core” Query Language. At the time of this rechartering, the Working Group is expecting to publish the following additional documents as Recommendations:

Test Suites

The group expects to create a test suite for each specification.

Errata

The group will also take into consideration the errors on the documents reported by the community since the publication of of the SPARQL documents in January 2008, and stored in the public archives of the relevant mailing list.

Milestones

Milestones
Note: The group will document significant changes from this initial schedule on the group home page.
Specification FPWD LC CR PR Rec
SPARQL 1.1 Query Language Oct 2009 May 2011 Oct 2011 Jan 2012 Mar 2012
SPARQL 1.1 Update Language Oct 2009 May 2011 Oct 2011 Jan 2012 Mar 2012
SPARQL 1.1 Protocol Oct 2009 Jun 2011 Oct 2011 Jan 2012 Mar 2012
SPARQL 1.1 Query Results XML Format Not currently deemed necessary
SPARQL 1.1 Query Results JSON Format Jul 2011 Jul 2011 Oct 2011 Jan 2012 Mar 2012
SPARQL 1.1 Query Results CSV/TSV Format Jul 2011 TBD if WG opts for Rec Track
SPARQL 1.1 Federation Extensions Jun 2010 Jun 2011 Oct 2011 Jan 2012 Mar 2012
SPARQL 1.1 Graph Store HTTP Protocol Oct 2009 May 2011 Oct 2011 Jan 2012 Mar 2012
SPARQL 1.1 Service Description Oct 2009 May 2011 Oct 2011 Jan 2012 Mar 2012
SPARQL 1.1 Entailment Regimes Oct 2009 May 2011 Oct 2011 Jan 2012 Mar 2012
SPARQL 1.1 Overview Jul 2011 Jul 2011 Oct 2011 Jan 2012 Mar 2012

Dependencies

W3C Groups

Semantic Web Coordination Group
To ensure synchronization with all other Working and Interest Groups in the Semantic Web Activity
OWL and RIF Working Groups
On interoperability measures with OWL and/or RIF inference regimes, the details should be checked with the relevant group(s).
Internationalization Activity
To ensure that any extension to string related filters and operators would work in an international setting
XML Query Working Group
To take into account possible extensions and changes in the specification of the XQuery 1.1/XPath Functions & Operators, and experiences in the XQuery Update Facility work.
XML Schema Working Group
The Entailment Regimes specification is expected to make use of XML Schema Definition Language (XSD) 1.1 Part 2: Datatypes, a work-in-progress.
RDF Working Group
The group should review all work by the RDF Working Group that might affect SPARQL and provide feedback when necessary. Special effort should be made to keep alignment in the RDF model and between Turtle and SPARQL.

Participation

To be successful, the SPARQL Working Group is expected to have 10 or more active participants for its duration. Effective participation to SPARQL Working Group is expected to consume one work day per week for each participant; two days per week for editors.

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

Communication

This group primarily conducts its work on the Member-only mailing list public-rdf-dawg@w3.org (with a publicly visible archive) .

Information about the group (deliverables, participants, face-to-face meetings, teleconferences, etc.) is available from the SPARQL 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 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.

Historical notes:

EDIT: (14 August 2012) End Date updated from 30 June 2012 to 31 December 2012. (See previous version and color-coded diff)

EDIT: (29 January 2013) End Date updated from 31 December 2012 to 30 March 2013. (See previous version and color-coded diff)


Eric Prud’hommeaux, Ivan Herman, Sandro Hawke

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