This is a request to transition the SPARQL specifications of the RDF Data Access Working Group to W3C Proposed Recommendation and to call for their review and endorsement by the W3C members. This request covers three specifications:
(Please note that local links in the status sections are local to the specifications rather than to this transition request.)
We propose to publish the documents at the following "this version" and "latest version" URIs (noting that the date portion of the URI will change with any change to the publication dates):
Current version URIs:
Latest version URIs:
These correspond to the following editors' draft URIs:
These editors' working drafts, after final editorial corrections, are set up to be published by moving them to the publication URIs above.
We propose that the specifications be published immediately after the November publication moratorium, on 12-Nov-2007.
We propose that the PR period lasts four weeks, until 10-Dec-2007 (adjusted if the publication date changes). Based on the length of time that the specifications have been around and the large number of implementations, we believe that a four week review period should be sufficient.
RDF is a directed, labeled graph data format for representing information in the Web. This specification defines the syntax and semantics of the SPARQL query language for RDF. SPARQL can be used to express queries across diverse data sources, whether the data is stored natively as RDF or viewed as RDF via middleware. SPARQL contains capabilities for querying required and optional graph patterns along with their conjunctions and disjunctions. SPARQL also supports extensible value testing and constraining queries by source RDF graph. The results of SPARQL queries can be results sets or RDF graphs.
This section describes the status of this document at the time of its publication. Other documents may supersede this document. A list of current W3C publications and the latest revision of this technical report can be found in the W3C technical reports index at http://www.w3.org/TR/.
This November 2007 publication is a Proposed Recommendation. W3C Members and other interested parties are invited to review the document through 10 December 2007.
This document is a product of the RDF Data Access Working Group and, in conjunction with the SPARQL Protocol for RDF and the SPARQL Query Results XML Format satisfies the requirements documented in RDF Data Access Use Cases and Requirements.
The first release of this document was 12 Oct 2004 and the RDF Data Access Working Group has made its best effort to address comments received since then, releasing several drafts and resolving a list of issues meanwhile. The group published a 26 March 2007 Last Call Working Draft. The change log enumerates changes since the publication of a 14 June 2007 Candidate Recommendation.
Since the Candidate Recommendation publication, the Working Group made a non-editorial correction to the specification to bring it in line with the Working Group's intent as expressed in the test suite. In particular, the algorithm for handling filters in the section on converting graph patterns was simplified to:
If F is not empty: G := Filter(F, G)
in response to the bug described in a 26 September message on the Working Group's mailing list. The same message identifies seven tests that correctly demonstrate the Working Group's intent. An examination of the results of these seven tests in the results submitted by eleven implementations indicate that implementors have all followed the intent of the algorithm rather than the formal semantics of the Candidate Recommendation specification.
The Working Group also recognized an ambiguity in the simplification step of the algorithm for converting graph patterns to algebraic expressions. The Working Group chose to leave resolution of the ambiguity to future work, noting a lack of consensus in which way to resolve the ambiguity and the unlikely nature of the ambiguity arising in practice. To help future tracking of the ambiguity, the Chair created and postponed the simplificationAmbiguity issue. Text noting the ambiguity and relevant test cases is included in this document.
The Working Group has satisfied the exit criteria set forth in the June 2007 Candidate Recommendation as follows:
Both features at risk (the REDUCED query modifier and allowing leading digits in the local part of prefixed names) from the 14 June 2007 Candidate Recommendation publication are retained in this Proposed Recommendation.
Aside from formal membership reviews, comments on this document should be sent to public-rdf-dawg-comments@w3.org, a mailing list with a public archive.
Publication as a Proposed Recommendation does not imply endorsement by the W3C Membership. This is a draft document and may be updated, replaced or obsoleted by other documents at any time. It is inappropriate to cite this document as other than work in progress.
This document was produced by a group operating under the 5 February 2004 W3C Patent Policy. W3C maintains a public list of any patent disclosures made in connection with the deliverables of the group; that page also includes instructions for disclosing a patent. An individual who has actual knowledge of a patent which the individual believes contains Essential Claim(s) must disclose the information in accordance with section 6 of the W3C Patent Policy.
The SPARQL Protocol and RDF Query Language (SPARQL) is a query language and protocol for RDF. This document specifies the SPARQL Protocol; it uses WSDL 2.0 to describe a means for conveying SPARQL queries to an SPARQL query processing service and returning the query results to the entity that requested them. This protocol was developed by the W3C RDF Data Access Working Group (DAWG), part of the Semantic Web Activity as described in the activity statement .
This section describes the status of this document at the time of its publication. Other documents may supersede this document. A list of current W3C publications and the latest revision of this technical report can be found in the W3C technical reports index at http://www.w3.org/TR/.
This November 2007 publication is a Proposed Recommendation. W3C Members and other interested parties are invited to review the document through 10 December 2007.
This document is a product of the RDF Data Access Working Group and, in conjunction with the SPARQL Query Language for RDF and the SPARQL Query Results XML Format satisfies the requirements documented in RDF Data Access Use Cases and Requirements.
The first release of this document was 14 Jan 2005 and the RDF Data Access Working Group has made its best effort to address comments received since then, releasing several drafts and resolving a list of issues meanwhile. The group published a 25 January 2006 Last Call Working Draft, followed by a 6 Apr 2006 Candidate Recommendation. The change log summarizes changes since the publication of the Candidate Recommendation, and contains a log of changes since the Last Call draft.
The Working Group has satisfied the exit criteria set forth in the 6 April 2006 Candidate Recommendation as follows:
Aside from formal membership reviews, comments on this document should be sent to public-rdf-dawg-comments@w3.org, a mailing list with a public archive.
Publication as a Proposed Recommendation does not imply endorsement by the W3C Membership. This is a draft document and may be updated, replaced or obsoleted by other documents at any time. It is inappropriate to cite this document as other than work in progress.
This document was produced by a group operating under the 5 February 2004 W3C Patent Policy. W3C maintains a public list of any patent disclosures made in connection with the deliverables of the group; that page also includes instructions for disclosing a patent. An individual who has actual knowledge of a patent which the individual believes contains Essential Claim(s) must disclose the information in accordance with section 6 of the W3C Patent Policy.
RDF is a flexible, extensible way to represent information about World Wide Web resources. It is used to represent, among other things, personal information, social networks, metadata about digital artifacts like music and images, as well as provide a means of integration over disparate sources of information. A standardized query language for RDF data with multiple implementations offers developers and end users a way to write and to consume the results of queries across this wide range of information.
This document describes an XML format for the variable binding and boolean results formats provided by the SPARQL query language for RDF, developed by the W3C RDF Data Access Working Group (DAWG), part of the Semantic Web Activity as described in the activity statement .
This section describes the status of this document at the time of its publication. Other documents may supersede this document. A list of current W3C publications and the latest revision of this technical report can be found in the W3C technical reports index at http://www.w3.org/TR/.
This November 2007 publication is a Proposed Recommendation. W3C Members and other interested parties are invited to review the document through 10 December 2007.
This document is a product of the RDF Data Access Working Group and, in conjunction with the SPARQL Protocol for RDF and the SPARQL Query Language for RDF satisfies the requirements documented in RDF Data Access Use Cases and Requirements.
The first release of this document was 21 Dec 2004 and the RDF Data Access Working Group has made its best effort to address comments received since then, releasing several drafts and resolving a list of issues meanwhile. The group published a 14 June 2007 Last Call Working Draft, followed by a 25 September 2007 Candidate Recommendation. The change log contains a summary of changes to this document.
The Working Group has satisfied the exit criteria set forth in the June 2007 Candidate Recommendation as follows:
Aside from formal membership reviews, comments on this document should be sent to public-rdf-dawg-comments@w3.org, a mailing list with a public archive.
Publication as a Proposed Recommendation does not imply endorsement by the W3C Membership. This is a draft document and may be updated, replaced or obsoleted by other documents at any time. It is inappropriate to cite this document as other than work in progress.
This document was produced by a group operating under the 5 February 2004 W3C Patent Policy. W3C maintains a public list of any patent disclosures made in connection with the deliverables of the group; that page also includes instructions for disclosing a patent. An individual who has actual knowledge of a patent which the individual believes contains Essential Claim(s) must disclose the information in accordance with section 6 of the W3C Patent Policy.
The decision to request the transition to Proposed Recommendation was advised by a Web survey and confirmed in the 23 Oct 2007 teleconference.
Various clarifications and editorial changes were added to the document during Candidate Recommendation and are summarized and listed in detail in the change log. Of these, two are of particular note as they directly relate to the semantics of the query language. Both are explicitly discussed in the status section and are repeated here with commentary:
Since the Candidate Recommendation publication, the Working Group made a non-editorial correction to the specification to bring it in line with the Working Group's intent as expressed in the test suite. In particular, the algorithm for handling filters in the section on converting graph patterns was simplified to:
If F is not empty: G := Filter(F, G)
in response to the bug described in a 26 September message on the Working Group's mailing list. The same message identifies seven tests that correctly demonstrate the Working Group's intent. An examination of the results of these seven tests in the results submitted by eleven implementations indicate that implementors have all followed the intent of the algorithm rather than the formal semantics of the Candidate Recommendation specification.
Because seven approved test cases have given the correct semantics of this part of the specification and because there is significant evidence that no implementations were misled by the bug in the previous specification text, the Working Group believes that fixing this part of the specification does not invalidate any previous reviews of the specification.
The Working Group also recognized an ambiguity in the simplification step of the algorithm for converting graph patterns to algebraic expressions. The Working Group chose to leave resolution of the ambiguity to future work, noting a lack of consensus in which way to resolve the ambiguity and the unlikely nature of the ambiguity arising in practice. To help future tracking of the ambiguity, the Chair created and postponed the simplificationAmbiguity issue. Text noting the ambiguity and relevant test cases is included in this document.
The Working Group believes that the circumstances under which this ambiguity arises are corner cases that are unlikely to occur in practice. Given this, the Working Group felt that the interoperability concerns of leaving an ambiguity in the specification did not warrant the time that would have been required to reach consensus on an appropriate resolution of the ambiguity. Because the construct will rarely if ever arise in practice, the Working Group feels that noting the ambiguity as a postponed issue will allow future groups to safely resolve the ambiguity if future experience guides consensus on a proper resolution.
The Candidate Recommendation publication of the SPARQL Query Language for RDF contained two features at-risk. These features have been retained in the current draft and have received support from the wider community. These features are:
One clarification to the specification and a small number of typo fixes to the accompanying WSDL and schema files were made during Candidate Recommendation and are summarized and listed in detail in the change log. There is no reason to believe that these changes would invalidate any previous reviews of this specification. This specification contained no at-risk features.
No changes were made to this specification during Candidate Recommendation. This specification contained no at-risk features.
There have been no changes to the Working Group's requirements since the specifications' transitions to Candidate Recommendation. The three specifications satisfy the requirements detailed in RDF Data Access Use Cases and Requirements as follows:
The transition call that preceded the advancement of the SPARQL Query Language for RDF to Candidate Recommendation suggested two pieces of work that the Working Group might tackle while in CR. While the Working Group has not made formal progress on these two topics, the work done to generate an implementation report is enlightening:
Dependencies were discharged as follows:
SPARQL has received wide review in a number of forms.
About 80 people participated in the comments mailing list, including editors and WG members. Tutorial articles include:
Formal treatments of SPARQL have also been produced, including:
A community-maintained list of SPARQL software includes SPARQL engines in progress in PHP, Java, Perl, python C, and Common Lisp, as well as client side utilities and parsers. The companion list of services and applications and list of SPARQL endpoints include interactive forms that allow developers and users to evaluate the language over the web and a few medium to large scale, though experimental, services. We have not evaluated the completeness of these services and software, though this level of support clearly indicates significant investment in and satisfaction with the SPARQL specifications and justifies continued investment in finishing the test materials.
Further evidence of wide review since publication of the Candidate Recommendation is the receipt of implementation results from 14 distinct SPARQL implementations, including seven implementations not associated with Working Group members.
All comments received during Candidate Recommendation have been addressed by the Working Group. Please see the following Dispositions of Comments for the three specifications, which in-turn reference comment dispositions from previous transitions:
The DAWG has seven objections on record over the lifetime of the Working Group. Six of these objections existed from before the transition to Candidate Recommendation, and one objection has been newly raised. Note that the new objection is actually support for an objection first raised in July of 2004.
Please see the following implementation reports:
We maintain a public list of any patent disclosures. Currently there have been no patent disclosures for these specifications.
Thanks to both the GRDDL working group and to Dan Connolly for the format of this transition request.
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