XML Query Working Group Charter
The mission of the XML Query Working Group, part of the Extensible Markup Language (XML) Activity, is to provide flexible query facilities to extract data from XML and virtual documents, such as contents of databases or other persistent storage that are viewed as XML via a mapping mechanism, on the Web.
| End date | 31 January 2011 |
|---|---|
| Confidentiality | Proceedings are Member-only |
| Initial Chair | Jim Melton |
| Initial Team Contacts (FTE %: 30) |
Liam Quin |
| Usual Meeting Schedule | Telcons: Weekly Ftf: 4 per year |
Scope
The functionality of the XML Query language encompasses selecting whole documents or components of documents based on specified selection criteria, as well as constructing XML documents from selected components.
The goal of the XML Query Working Group is to produce and maintain a formal data model for XML documents with namespaces (based on the XML Information Set), a set of query operators on that data model (a so-called algebra), and then a query language with a concrete canonical syntax based on the proposed operators. The queries allowed by the query language should be computable and terminating. Such queries will act on fixed collections of XML documents. Functionalities include full-text text search (as opposed to simple substring search), update instances of the query data model, and a set of XQuery Scripting Extensions intended to facilitate the use of XML Query in developing applications.
Success Criteria
The Working Group expects to demonstrate at least 2 interoperable implementations of all required and optional features of any new Specification before requesting to advance to Proposed Recommendation.
Deliverables
Jointly with the XSL Working Group, a set of W3C Recommendations for:
- XQuery and XPath Full Text 1.0
- XML Path Language (XPath) 2.1
- XQuery 1.1 and XPath 2.1 Data Model (XDM)
- XQuery 1.1 and XPath 2.1 Functions and Operators
- XSLT 2.1 and XQuery 1.1 Serialization
- XQuery and XPath Full Text 1.1
In addition, if sufficient resources are available, a joint W3C Recommendations for XQuery 1.1 and XPath 2.1 Formal Semantics.
A set of W3C Recommendations for:
- XQuery Update Facility 1.0
- XQuery Scripting Extension 1.0
- XQuery 1.1: An XML Query Language
- XML Syntax for XQuery 1.1 (XQueryX)
- XQuery Update Facility 1.1
- XQuery Scripting Extension 1.1
XQuery and XPath Full Text 1.0, XQuery Update Facility 1.0, and XQuery Scripting Extension 1.0 have been written to augment XPath 2.0 and XQuery 1.0. In a similar way, XQuery and XPath Full Text 1.1, XQuery Update Facility 1.1, and XQuery Scripting Extension 1.1 will augment XPath 2.1 and XQuery 1.1. The 1.1 versions of the Full Text, Update and Scripting specifications are expected to be functionally the same as the 1.0 versions, but augment XQuery 1.1 instead of 1.0.
The following documents will become Working Group Notes:
- XQuery and XPath Full Text 1.0 Requirements
- XQuery and XPath Full Text 1.0 Use Cases
- XML Query (XQuery) 1.1 Requirements
- XML Query (XQuery) 1.1 Use Cases
- XPath Requirements Version 2.1
- XPath Requirements Version 2.1
- XQuery Update Facility 1.0 Requirements
- XQuery Update Facility 1.0 Use Cases
- Building a Tokenizer for XPath or XQuery
- XQuery Scripting Extension 1.0 Requirements
- XQuery Scripting Extension 1.0 Use Cases
Other Deliverables
The following additional items will be developed and/or maintained by the XML Query Working Group:
- An interoperability test suite for XQuery Full Text 1.0: intended to assess the accuracy of the Candidate Recommendation, and to promote interoperability.
- An interoperability test suite for XQuery Update Facility 1.0: intended to assess the accuracy of the Candidate Recommendation, and to promote interoperability.
- An interoperability test suite for XQuery Scripting Extension 1.0: intended to assess the accuracy of the Candidate Recommendation, and to promote interoperability.
- An interoperability test suite for XQuery 1.1 and XQueryX 1.1: intended to assess the accuracy of the Candidate Recommendations, and to promote interoperability.
- An interoperability test suite for XQuery Full Text 1.1: intended to assess the accuracy of the Candidate Recommendation, and to promote interoperability.
- An interoperability test suite for XQuery Update Facility 1.1: intended to assess the accuracy of the Candidate Recommendation, and to promote interoperability.
- An interoperability test suite for XQuery Scripting Extension 1.1: intended to assess the accuracy of the Candidate Recommendation, and to promote interoperability.
The XML Query WG and the XSL WG have been maintaining XQuery 1.0 and XPath 2.0 since their publication in Jan. 2007. These Recommendations will be published as Second Editions in early 2009. It is possible that the WGs will publish additional editions of these Recommendations.
The XQuery Working Group may also update documents as appropriate to support validation using XML Schema (XSD) 1.1, as that specification progresses to Recommendation.
Milestones
| Specification | FPWD | LC | CR | PR | Rec |
|---|---|---|---|---|---|
| Note: The group will document significant changes from this initial schedule on the group home page. | |||||
| XQuery and XPath Full Text 1.0 | N/A | N/A | N/A | April 2009 | June 2009 |
| XQuery Update Facility 1.0 | N/A | N/A | N/A | February 2009 | April 2009 |
| XQuery Scripting Extension 1.0 | N/A | October 2009 | February 2010 | May 2010 | September 2010 |
| XQuery 1.1 | N/A | May 2009 | October 2009 | February 2010 | May 2010 |
| XQueryX 1.1 | January 2009 | May 2009 | October 2009 | February 2010 | May 2010 |
| XML Path Language (XPath) 2.1 | January 2009 | May 2009 | October 2009 | February 2010 | May 2010 |
| XQuery 1.1 and XPath 2.1 Data Model | January 2009 | May 2009 | October 2009 | February 2010 | May 2010 |
| XQuery 1.1 and XPath 2.1 Functions and Operators | January 2009 | May 2009 | October 2009 | February 2010 | May 2010 |
| XQuery 1.1 and XPath 2.1 Formal Semantics | January 2009 | May 2009 | October 2009 | February 2010 | May 2010 |
| XSLT 2.1 and XQuery 1.1 Serialization | January 2009 | May 2009 | October 2009 | February 2010 | May 2010 |
| XQuery and XPath Full Text 1.1 | April 2009 | May 2009 | October 2009 | February 2010 | May 2010 |
| XQuery Update Facility 1.1 | January 2009 | May 2009 | October 2009 | February 2010 | May 2010 |
Timeline View Summary
- January 2009, First Public Working Draft for XQueryX 1.1
- February 2009, Proposed Recommendation for XQuery Update Facility 1.0
- April 2009, Proposed Recommendation for XQuery and XPath Full Text 1.0; Recommendation for XQuery Update Facility 1.0
- May 2009, Last Call for XQueryX 1.1
- June 2009, Recommendation for XQuery and XPath Full Text 1.0
- October 2009, Last Call for XQuery Scripting Extension 1.0; Candidate Recommendation for XQueryX 1.1
- February 2010, Proposed Recommendation for XQueryX 1.1; Candidate Recommendation for XQuery Scripting Extension 1.0
- May 2010, Proposed Recommendation for XQuery Scripting Extension 1.0; Recommendation for XQueryX 1.1
- September 2010, Recommendation for XQuery Scripting Extension 1.0
Duration
The expiration date of this charter is 31 January 2011.
Dependencies
W3C Groups
- XSL
- The XPath 1.0 language was developed by the XSL Working Group. The XPath 2.0 language was jointly developed by the XSL Working Group and the XML Query Working Group. The groups also jointly developed several other documents supporting XPath 2.0 and XSLT 2.0. The two groups will continue to collaborate on the development of XPath 2.1 and its supporting documents.
- XML Schema
- It is a goal of the XML Query work to be compatible with the work of the XML Schema Working Group on XML Schema Part 2: Datatypes (XML Schema Part 2) and XML Schema Part 1: Structures (XML Schema Part 1). For example, it should be possible to base query predicates on the existing DTD or XML Schema Part 1 definition of the content of an XML document and on the data types defined as part of W3C XML Schema Part 2.
- XML Core
- The XML Query work has defined and will extend a formal data model of XML documents. This model must be based on the model of the XML Infoset (XML Information Set). In case incompatibilities arise, requirements must be posed to the XML Core Working Group. In any case, the final model used by the XML Query working group will have to be based on, and totally compatible with, the model of the XML Infoset. In addition any XML Query definition of an XML fragment will take into consideration the XML Fragment Interchange specification (XML Fragment Interchange)
- Internationalization Core
- It is a goal of the XML Query work to ensure proper internationalization of the XML Query technology. The mission and scope of the Internationalization Working Group is to propose and coordinate any techniques, conventions, guidelines and activities within the W3C that help to make and keep the Web international. The XML Query Working Group and the Internationalization Working Group will work together to agree on specific I18N requirements and find solutions.
There are no requirements for co-development of features with the following Working Groups, but there are points of contact between their work and that of this Working Group, and thus logical dependency between their deliverables and those of this Working Group. Requirements from these Working Groups are expected to be well suited for communication via documents:
- WAI Protocols & Formats Working Group
- Reuse of common constructs greatly facilitates accessibility; the WAI PF Working Group will review work on the XML query facilities to be sure cost/benefit design decisions are informed of the benefits of accessibility.
- RDF Data Access Working Group
- The relationship with XQuery section mentions that the RDF DAWG should aim to maximize W3C technology re-use, such as using the XQuery 1.0 and XPath 2.0 Functions and Operators specification. The RDF Data Access Working Group and the XML Query Working Group will coordinate to ensure the reusability of the XQuery/XPath technologies.
When approved by the XML Coordination Group, liaison with other W3C Working Groups can be accomplished through joint task forces. It is expected that this be required for liaison with at least the XML Schema, XSL and Internationalization Working Groups.
Participation
To be successful, the XML Query Working Group is expected to have 6 or more active participants for its duration. Effective participation to XML Query Working Group is expected to consume half of a work day per week for each participant; two days per week for editors. The XML Query 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.
Communication
This group primarily conducts its work on the Member-only mailing list
w3c-xml-query-wg@w3.org (archive), as
well as various other lists: w3c-xsl-query@w3.org (archive), member-query-fttf@w3.org
(archive)
and member-query-test@w3.org
(archive).
Public feedback happens through public-qt-comments@w3.org (archive).
Information about the group (deliverables, participants, face-to-face meetings, teleconferences, etc.) is available from the XML Query Working Group home page.
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 XML Query Working Group has been created according to section 6.2 of the Process Document. In the event of a conflict between the provisions of any charter and the W3C Process, the W3C Process shall take precedence.
Please also see the previous charter for this group.
Liam Quin, XML Activity Lead and Team Contact
Copyright© 2006 W3C ® (MIT , ERCIM , Keio), All Rights Reserved.
$Date: 2009/02/19 19:57:59 $