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697 lines
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697 lines
32 KiB
<?xml version="1.0" encoding="utf-8"?>
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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
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"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
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<html xmlns="http://www.w3.org/1999/xhtml">
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<head>
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<title>Transition Request to advance SPARQL to Candidate
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Recommendation</title>
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<style type="text/css">
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.pub-status {background-color: #F1F1F1; color: #000000;
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border-left: dotted; padding-left: 1em}
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</style>
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</head>
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<body>
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<div class="nav"><a href="./">DAWG</a></div>
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<p>This is a <a href=
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"http://www.w3.org/2005/08/transition?docstatus=cr-tr">transition
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request to CR</a> for the three documents that specify SPARQL. Whereas</p>
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<ul>
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<li>W3C established our <a href=
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"http://www.w3.org/2003/12/swa/dawg-charter">charter</a>
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in February 2004 (and extended it in January 2006)</li>
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<li>we have elaborated on the value of this work to the
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community by way of <a href=
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"http://www.w3.org/TR/rdf-dawg-uc/">use cases and derived
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design requirements</a></li>
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<li>we have developed specifications for SPARQL that meet our
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charter and requirements</li>
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<li>this specification has received wide review, within the
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Working Group and the community, and we have addressed the
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issues raised in this review with consensus on all but
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about <a href="#obj">ten cases</a>.</li>
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</ul>
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<p>the RDF Data Access Working Group decided (<a href=
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"http://lists.w3.org/Archives/Public/public-rdf-dawg/2006JanMar/0465.html"
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>21 Mar meeting minutes</a>, pending successful outcome of <a
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href="http://www.w3.org/2002/09/wbs/35463/crq349/">ballot</a> ) to
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request that you advance this specification to W3C Candidate
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Recommendation and call for implementation.
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</p>
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<ul>
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<li>
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<cite><a href="http://www.w3.org/TR/rdf-sparql-query/">SPARQL
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Query Language for RDF</a></cite>
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<br />Abstract:
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<blockquote>
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<p>RDF is a flexible and extensible way to
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represent information about World Wide Web resources. It
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is used to represent, among other things, personal
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information, social networks, metadata about digital
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artifacts, as well as provide a means of integration over
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disparate sources of information. A standardized query
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language for RDF data with multiple implementations
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offers developers and end users a way to write and to
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consume the results of queries across this wide range of
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information. Used with a common protocol, applications
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can access and combine information from across the Web.</p>
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<p>This document describes the query language part of
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the SPARQL Protocol And RDF Query Language for easy
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access to RDF stores. It is designed to meet the
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requirements and design objectives described in
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<cite><a href="http://www.w3.org/TR/rdf-dawg-uc/">RDF
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Data Access Use Cases and Requirements</a></cite></p>
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</blockquote>
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<p><em>specifically, <a href="rq23">ed draft</a>
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1.664 2006/03/21 10:19:30, with appendixes:
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sparql-defns.html 1.3 2006/02/21 20:14:59,
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parsers/sparql.bnf 1.1 2006/02/09 23:12:43, plus edits
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as agreed 21 March
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</em></p>
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</li>
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<li>
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<cite><a href=
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"http://www.w3.org/TR/rdf-sparql-protocol/">SPARQL Protocol
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for RDF</a></cite>
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<br />Abstract:
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<blockquote>
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<p>SPARQL is a query language and protocol for <a href=
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"http://www.w3.org/RDF/">RDF</a>. This document specifies
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the SPARQL Protocol; it uses <a href=
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"http://www.w3.org/TR/wsdl20/">WSDL 2.0</a> to describe a
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means for conveying SPARQL queries to an SPARQL query
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processing service and returning the query results to the
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entity that requested them.</p>
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</blockquote>
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<p><em>specifically, <a href="proto-wd/">ed draft</a> v1.114 of
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2006/03/20 21:58:41 and the 2 linked WSDL files:
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<tt>sparql-protocol-query.wsdl,v 1.18 2006/03/21 19:18:07</tt>
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and <tt>sparql-protocol-types.xsd,v 1.17 2006/01/11
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19:15:22</tt>, plus edits as agreed 21 March </em></p>
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</li>
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<li>
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<cite><a href=
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"http://www.w3.org/TR/rdf-sparql-XMLres/">SPARQL Query
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Results XML Format</a></cite>
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<br />Abstract:
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<blockquote>
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<p>RDF is a flexible, extensible way to
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represent information about World Wide Web resources. It
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is used to represent, among other things, personal
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information, social networks, metadata about digital
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artifacts like music and images, as well as provide a
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means of integration over disparate sources of
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information. A standardized query language for RDF data
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with multiple implementations offers developers and end
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users a way to write and to consume the results of
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queries across this wide range of information.</p>
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<p>This document describes an XML format for the variable
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binding and boolean results formats provided by the
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SPARQL query language for RDF.</p>
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</blockquote>
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<p><em>specifically: <a href="rf1/">ed draft</a> v1.78 of
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2006/01/04T15:59:22Z</em></p>
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</li>
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</ul>
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<hr />
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<div><h2>Status of these documents (proposed)</h2>
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<p><em>tweaks to be made in the publication process are marked
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PUBFIX</em></p>
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<blockquote class="pub-status">
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<p><em>This section describes the status of this document at the time of its publication[PUBFIX which hasn't happened yet]. 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 <a href="http://www.w3.org/TR/">W3C technical reports index</a> at http://www.w3.org/TR/.</em></p>
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<p>This 29 Mar 2006
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<em>[PUBFIX confirm]</em>
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draft, along with the other working drafts for SPARQL, are a
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<a href=
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"http://www.w3.org/2003/06/Process-20030618/tr.html#RecsCR">Candidate
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Recommendation</a>; it been widely reviewed and satisfies the
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requirements documented in <b><i><a href=
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"http://www.w3.org/TR/rdf-dawg-uc/">RDF Data Access Use Cases and
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Requirements</a></i></b> ; W3C publishes a Candidate
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Recommendation to gather implementation experience.</p>
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<p>The first release of this document was 12 Oct 2004<em>[PUBFIX tune to
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each part</em>] and the <a href=
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"http://www.w3.org/2001/sw/DataAccess/">RDF Data Access Working
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Group</a> has made its best effort to address <a href=
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"http://lists.w3.org/Archives/Public/public-rdf-dawg-comments/">comments
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received</a> since then, releasing several drafts and resolving a <a
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href="http://www.w3.org/2001/sw/DataAccess/issues">list of
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issues</a> meanwhile. The design has stabilized and the Working Group intends to advance this
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specification to Proposed Recommendation
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once the exit
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criteria below are met:</p>
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<ul id="exitcri"> <!-- hmm... xoxo? VTodos? -->
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<li>A test suite gives reasonable coverage of
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the features of the query language and protocol.
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<p>Note that the working group maintains a <a
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href="http://www.w3.org/2001/sw/DataAccess/tests/">collection of
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query tests</a> and a <a
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href="http://www.w3.org/2001/sw/DataAccess/proto-tests/">collection
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of protocol tests</a>. Only a portion of the tests in these
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collections are approved at this time.</p>
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</li>
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<li>Each identified SPARQL feature has at least two implementations.</li>
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<li>At least two <a href="proto-wd/#conformant-sparql-protocol-service">conformant SPARQL service</a>s are available. [PUBFIX update link to /TR/ space]</li>
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<li>Relevant media types are registered:
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<ul>
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<li>The SPARQL
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specifications introduce two new Internet Media Types. Review
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has been requested, but the types are not yet registered:
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<ul>
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<li>application/sparql-query: <a href=
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"http://www.alvestrand.no/pipermail/ietf-types/2005-November/000895.html">
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review request</a> of 24 Nov 2005</li>
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<li>application/sparql-results+xml: <a href=
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"http://www.alvestrand.no/pipermail/ietf-types/2005-November/000894.html">
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review request</a> of 24 Nov 2005</li>
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</ul>
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</li>
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<li>The SPARQL protocol specification uses the ext/rdf+n3 media type, which is unregistered, in an example</li>
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</ul>
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</li>
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<li>Normative dependencies, have been advanced to Proposed
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Recommendation status:
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<ul>
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<li><cite><a href="http://www.w3.org/TR/xpath-functions/">XQuery
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1.0 and XPath 2.0 Functions and Operators</a></cite></li>
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<li><cite><a href="http://www.w3.org/TR/wsdl20">Web Services
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Description Language (WSDL) Version 2.0 Part 1: Core Language
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</a></cite></li>
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<li><cite><a href="http://www.w3.org/TR/wsdl20-adjuncts">Web
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Services Description Language (WSDL) Version 2.0 Part 2:
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Adjuncts</a></cite></li>
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</ul>
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</li>
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</ul>
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<p>This specification will
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remain a Candidate Recommendation until at least 30 May
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2006[PUBFIX if 29 March slips, so does this].
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An <a href="http://www.w3.org/2001/sw/DataAccess/imp39">implementation
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report</a> is in progress.</p>
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<p>Comments on this document should be sent to
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public-rdf-dawg-comments@w3.org, a mailing list with a <a href=
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"http://lists.w3.org/Archives/Public/public-rdf-dawg-comments/">public
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archive</a>.</p>
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<p>Publication as a Candidate 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.</p>
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<p> This document was produced by a group operating under the <a href="http://www.w3.org/Consortium/Patent-Policy-20040205/">5 February 2004 W3C Patent Policy</a>. W3C maintains a <a rel="disclosure" href="http://www.w3.org/2004/01/pp-impl/35463/status">public list of any patent disclosures</a> 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 <a href="http://www.w3.org/Consortium/Patent-Policy-20040205/#def-essential">Essential Claim(s)</a> must disclose the information in accordance with <a href="http://www.w3.org/Consortium/Patent-Policy-20040205/#sec-Disclosure">section 6 of the W3C Patent Policy</a>. </p>
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</blockquote>
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</div>
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<hr />
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<div><h2>Summary of Review</h2>
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<p>The first public working draft of the SPARQL specification was
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released in Oct 2004, following a June 2004 Use Cases and
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Requirements release. The November 2004 Last Call milestone from our
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charter was delayed due to difficulties reaching consensus on an
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initial design and requirements; see <a href="#obj">outstanding
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dissent</a> below. We adopted a WSDL requirement and a sorting
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objective in early 2005, accepting another schedule slip. Our
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requirements have been stable since the March 2005 draft. In a
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number of cases, we have considered features that go beyond these
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requirements, but ultimately postponed them due to lack of
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implementation and design experience. For example, <a href=
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"http://www.w3.org/2001/sw/DataAccess/issues#accessingCollections"
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>Features for querying lists/collections</a> have been frequently
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requested, but the requestors seem to be satisfied with our decision
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to postpone the issue.</p>
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<p>About 75 people participated in the comments mailing list,
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including editors and WG members. Tutorial articles include:</p>
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<ul>
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<li><cite><a href="http://www-128.ibm.com/developerworks/xml/library/j-sparql/">Search RDF data with SPARQL</a></cite> by Philip McCarthy 10 May 2005 on IBM developerWorks</li>
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<li><cite><a href="http://www.xml.com/pub/a/2005/11/16/introducing-sparql-querying-semantic-web-tutorial.html">Introducing SPARQL: Querying the Semantic Web</a></cite> by Leigh Dodds November 16, 2005 on XML.com</li>
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</ul>
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<p>A community-maintained <a
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href="http://esw.w3.org/topic/SparqlImplementations">list of SPARQL
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software</a> includes SPARQL engines in progress in PHP, Java, Perl,
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python C, and Common Lisp, as well as client side utilities and
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parsers. The companion <a
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href="http://esw.w3.org/topic/DawgShows">list of services and
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applications</a> includes interactive forms that allow developers
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and users to evaluate the language over the web and a few medium to
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large scale, though experimental, services. We have not evaluated
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the completeness of these services and software, though this level
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of support clearly indicates significant investment in and
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satisfaction with the SPARQL specifications and justifies continued
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investment in finishing the test materials.</p>
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<p>Dependencies were discharged as follows:</p>
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<ul>
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<li>The XML Query WG and XSL WG sent review <a href=
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"http://www.w3.org/mid/20050913082804661.00000000668@amalhotr-pc">
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comments</a> in Sep 2005. We sent a <a href=
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"http://www.w3.org/mid/43843C24.1080901@hp.com">response</a> that
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addressed them in Nov 2005. A <a
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href="http://lists.w3.org/Archives/Member/w3c-semweb-cg/2006Feb/0071">20
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Feb 2006 communication in the W3C Semantic Web Coordination
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Group</a> (member-confidential) suggests that the XSL and XQuery
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WGs are satisifed; we have not heard further from them.</li>
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<li>We requested review from the <a href=
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"http://www.w3.org/2001/sw/DataAccess/BestPractices/">Semantic
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Web Best Practices and Deployment (SWBPD) Working Group</a> in
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general and consulted members of that WG in particular on the
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SOURCE and UNSAID issues. This has resulted in various
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individual comments but no comments from the SWBPD WG as a
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whole.</li>
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<li>We exchanged comments with the WSD WG on a number of details
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related to specifying the SPARQL protocol using WSDL 2.0. While
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our September 2005 protocol draft conflicted with the then-current
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WSDL 2.0 specification, our 25 Jan 2006 protocol draft is in sync
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with latest information we have gotten from the WSD WG and the
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Woden validator (see <a
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href="http://lists.w3.org/Archives/Public/public-rdf-dawg/2006JanMar/thread.html#msg466">21
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March "wsdl fun" thread in DAWG</a>, <a
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href="http://lists.w3.org/Archives/Public/public-rdf-dawg-comments/2006Mar/0044.html">notice
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to wsd WG 21 March</a>).</li>
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<li>IETF review of SPARQL related media types
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(application/sparql-query, application/sparql-results+xml)
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began with review requests (<a href=
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"http://www.alvestrand.no/pipermail/ietf-types/2005-November/000895.html">query</a>
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r<a href=
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"http://www.alvestrand.no/pipermail/ietf-types/2005-November/000895.html">eview
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request</a> <a href=
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"http://www.alvestrand.no/pipermail/ietf-types/2005-November/000894.html">
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results</a> r<a href=
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"http://www.alvestrand.no/pipermail/ietf-types/2005-November/000894.html">eview
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request)</a> on 24 Nov 2005. We have not received any comments
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as a result. We accept registration of these media types as a
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CR exit criterion.</li>
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</ul>
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<p>In July 2005 and September 2005, we released last call
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working draft of the query language and protocol (respectively)
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since we had closed all outstanding issues and met all our
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requirements. Since then, there has been a sustained tension
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between a growing user and implementor community that is ready
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for the specification to advance despite any remaining flaws and a
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diligent review community that is insisting on a high level of
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rigor.</p>
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<p>We tracked <a
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href="http://lists.w3.org/Archives/Public/www-archive/2006Mar/att-0022/lc-status-report.html__charset_us-ascii">status
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of comments since July 2005</a>, including 55 cases of comments that
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the WG addressed to the documented satisfaction of the
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commentors. Due to a number of small technical changes and an
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increasing number of cases where the WG addressed a comment but did
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not get a clear indication of satisfaction or otherwise from the
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commentor, we issued a second last call of the SPARQL protocol 25
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Jan 2006 and the SPARQL query language 20 February 2006. Comments
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were due 13 March 2006; our <a
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href="http://www.w3.org/2001/sw/DataAccess/lc-status-report.html">comment
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status report</a> shows 9 threads where the WG and the commentor
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reached consensus, one case where the we
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"Corrected along the lines of your suggestion" and asked if it was
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satisfactory but have not seen a response. The remaining two threads
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are discussed under <a href="#obj">outstanding dissent</a> below.
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</p>
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<p>Changes since last call have been editorial changes and clarifications only.</p>
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</div>
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<div><h2 id="obj">Outstanding dissent (formal objections)</h2>
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<ol>
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<li>the WG RESOLVED <a href="http://www.w3.org/2001/sw/DataAccess/ftf2#initdn3">2004-07-15</a> to adopt BRQL v1.11 as its strawman query language design, over the <a href="http://lists.w3.org/Archives/Public/public-rdf-dawg/2004JulSep/0101.html">objection of RobS and JeffP of Network Inference</a>:
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<blockquote>...XQuery, with minor extensions, would be the best
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overall foundation on which to enable query-based access to the
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family of Semantic Web languages. ...</blockquote>
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<p>This view did not meet with a critical mass of support in
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Working Group discussions, though it continued to be explored in
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the community. One of the most thorough explorations of the
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relationship of SPARQL to XQuery and SQL concludes:</p>
|
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|
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<blockquote>
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<p>We have, somewhat reluctantly, concluded that the design
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goals of SQL and SPARQL are sufficiently different that there is
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adequate justification for the creation of a special-purpose
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language for querying RDF collections. We are comforted by the
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belief that it is possible to translate SPARQL expressions into
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SQL expressions, allowing users to store their RDF collections
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in relational databases if they wish to do so, and to write
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their queries in either SQL or in SPARQL, as they see fit. While
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predicting that it will be similarly possible to serialize RDF
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collections into XML documents and transform SPARQL expressions
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into XQuery expressions, we do not believe that most users would
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take that direction.</p>
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<cite><a
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href="http://www.idealliance.org/proceedings/xml05/abstracts/paper185.HTML">SQL,
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XQuery, and SPARQL What's Wrong With This Picture?</a></cite> by
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Jim Melton, Oracle Corporation; in <a
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href="http://www.idealliance.org/proceedings/xml05/index.html">proceedings
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of XML 2005</a>
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</blockquote>
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</li>
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<li>Requirement <a href="http://www.w3.org/TR/rdf-dawg-uc/#r3.6">3.6 Optional Match</a> was accepted <a href="http://www.w3.org/2001/sw/DataAccess/ftf2">2004-07-15</a> over the <a href="http://lists.w3.org/Archives/Public/public-rdf-dawg/2004JulSep/0104.html">objection of RobS of Network Inference</a>
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<p>Note that the objection concludes with:</p>
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<blockquote>
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...Network Inference certainly sees value in both features,
|
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and supports both as objectives for this working group. If the potential
|
|
problems related to these requirements can be overcome, then our
|
|
objection to the classification of these features as "requirements"
|
|
should not prevent the group from regaining consensus on a final
|
|
recommendation.
|
|
</blockquote>
|
|
<p>And while the theoretical issues with OPTIONAL have been
|
|
expensive to work out, they seem to be specified to the
|
|
satisfaction of the community. Further, the number of use cases
|
|
where this feature is critical suggests that SPARQL would not
|
|
succeed without it (For example, see <a href=
|
|
"http://lists.w3.org/Archives/Public/public-rdf-dawg-comments/2005Mar/0070"
|
|
>MacGregor 24 Mar 2005</a>.)</p>
|
|
</li>
|
|
|
|
<li>The <a href="http://www.w3.org/2001/sw/DataAccess/issues#DESCRIBE">DESCRIBE</a> issue was resolved over the objection of Dan Connolly:
|
|
<blockquote>
|
|
expectations around DESCRIBE are very different from CONSTRUCT and SELECT, and hence it should be specified in a separate query language
|
|
</blockquote>
|
|
<p>This objection was supported by a number of public comments; at
|
|
least one reviewer wrote to explicitly support this feature,
|
|
meanwhile. The feature seems to be specified to the satisfaction
|
|
of a critical mass of the community, supported in several
|
|
implementations, and used in a number of applications.</p>
|
|
</li>
|
|
|
|
<li>Objective <a href="http://www.w3.org/TR/rdf-dawg-uc/#d4.2">4.2 Data Integration and Aggregation</a> was accepted <a href="http://www.w3.org/2001/sw/DataAccess/ftf3-brs#obj564">2004-09-16</a> over the <a href="http://lists.w3.org/Archives/Public/public-rdf-dawg/2004JulSep/0118.html">objection of Network Inference/Rob Shearer</a>:
|
|
<blockquote>
|
|
<p>The only technology that I think we all really agree on is RDF and the
|
|
RDF data model. It strikes me as blatantly wrong to attempt a query
|
|
standard based on some other data model, and "RDF+some meta information"
|
|
is some other data model. If the meta information can be exposed in RDF,
|
|
then our query language should support it by default. If it can't be
|
|
exposed in RDF, then why are we considering native support in an RDF
|
|
query language?</p>
|
|
</blockquote>
|
|
|
|
<p>A comment from outside the WG also says:</p>
|
|
|
|
<blockquote>
|
|
<p>I think these should be removed from the basic SPARQL core, since I feel
|
|
they add a fair deal of implementation complexity and an application can
|
|
achieve the same result by submitting multiple queries, possibly to
|
|
different query processors.</p>
|
|
|
|
<p>I also feel it would be premature to standardize an approach to multi-graph
|
|
querying ahead of there being a consensus/standard for something like RDF
|
|
named graphs.</p>
|
|
<address><a href="http://lists.w3.org/Archives/Public/public-rdf-dawg-comments/2005Apr/0010.html">Klyne 08 Apr 2005</a></address>
|
|
</blockquote>
|
|
|
|
<p>The FROM NAMED and GRAPH features seems to be specified to the satisfaction
|
|
of a critical mass of the community, supported in several
|
|
implementations, and required by number of use cases and
|
|
applications.</p>
|
|
|
|
</li>
|
|
|
|
<li>The <a
|
|
href="http://www.w3.org/2001/sw/DataAccess/issues#fromUnionQuery">fromUnionQuery</a>
|
|
issue was resolved in our <a
|
|
href="http://lists.w3.org/Archives/Public/public-rdf-dawg/2005AprJun/0411.html">2005-06-07
|
|
meeting</a> over the objection of Steve Harris. This was a design
|
|
issue where the group had a lot of difficulty finding consensus,
|
|
and the chair chose to act in the interest of schedule concerns:
|
|
|
|
<blockquote>
|
|
<pre>
|
|
DanC summarized by observing 3 designs that seemed to be coherent
|
|
and had been developed and advocated sufficiently that we might
|
|
be able to finish them in a timely manner:
|
|
|
|
OPTIONS:
|
|
(a) without FROM/FROM_NAMED, dataset is unconstrained; with
|
|
FROM/FROM_NAMED, dataset is bounded from below by given references.
|
|
(b) like (a) but FROM/FROM named completely specify the dataset
|
|
(c) datasets have "aggregate graph" rather than background/default
|
|
graph, and it always contains the merge of the named graphs
|
|
|
|
By "bounded from below," DanC clarified that he meant D1 >= D2 iff
|
|
D1's background/aggregate graph has everything that D2's has,
|
|
i.e. D1's bg graph rdf-simply-entails D2's
|
|
and D1 has all the named graphs that D2 has; i.e.
|
|
for every named graph (U, G) in D2, (U, G) is also in D1's named
|
|
graphs.
|
|
|
|
KC observed that this is basically a web-social question of
|
|
constraining what publishers do.
|
|
|
|
DC observed that constraining publishers might be responsive
|
|
to comments on this part of our spec, in the interest of
|
|
interoperability at the expense of flexibility.
|
|
|
|
Polling showed significant opposition to (b); after that option
|
|
was removed, the WG was split nearly 50-50 between (a) and (c).
|
|
In the interest of time, the chair chose one of the proposals
|
|
and we
|
|
|
|
RESOLVED: to go option (a) without FROM/FROM_NAMED, dataset is
|
|
unconstrained; with FROM/FROM_NAMED, dataset is bounded from below
|
|
by given references.
|
|
SH objects. abstaining: EricP, DaveB
|
|
</pre>
|
|
</blockquote>
|
|
|
|
<p>The feature seems to be specified to the satisfaction of a
|
|
critical mass of the community, and it seems unlikely that
|
|
further deliberation of this issue would result in substantially
|
|
more consensus.</p>
|
|
</li>
|
|
|
|
<li>
|
|
The <a
|
|
href="http://www.w3.org/2001/sw/DataAccess/issues#rdfSemantics">rdfSemantics</a>
|
|
issue was closed in our <a
|
|
href="http://lists.w3.org/Archives/Public/public-rdf-dawg/2006JanMar/att-0298/26-dawg-minutes.html#item04">2006-01-26
|
|
meeting</a> over the objection of Pat Hayes, which was
|
|
that the definitions are overly complex. <p>This issue arose
|
|
from comments on the specification of matching in the July 2005
|
|
SPARQL draft with respect to the definition of RDF simple
|
|
entailment. After discussing a number of use cases and design
|
|
alternatives, the WG chose a design that was phrased in terms of
|
|
entailment in such a way that it should extend to OWL more
|
|
straightforwardly, but substantively, is not different from the
|
|
July 2005 draft. After discussing the details of the definitions
|
|
for some months, the chair observed a critical mass around a set
|
|
of definitions and put the question despite outstanding
|
|
dissent.</p>
|
|
</li>
|
|
|
|
<li>On 22 February, Peter F. Patel-Schneider sent
|
|
<a href="http://www.w3.org/mid/20060222.185654.133907622.pfps@research.bell-labs.com">comments on Section 1 and Section 2 of SPARQL Query Language for RDF</a>:
|
|
<blockquote>
|
|
<p>
|
|
In general I found the first two sections of the document <strong>very</strong> hard to
|
|
understand. The mixing of definitions, explanation, information, etc. confused
|
|
me over and over again. I strongly suggest an organization something like:</p>
|
|
|
|
<ul>
|
|
<li> Introduction (informative)</li>
|
|
<li> Formal development (normative)
|
|
<ul>
|
|
<li> Underlying notions (normative)</li>
|
|
<li> Patterns and matching (normative)</li>
|
|
</ul>
|
|
</li>
|
|
<li> SPARQL syntax (normative)</li>
|
|
<li> Informal narrative (informative)</li>
|
|
<li> Examples (informative)</li>
|
|
</ul>
|
|
|
|
<p>
|
|
I also found that things that didn't need to be explained were explained, and
|
|
things that did need to be explained were not explained. A major example of
|
|
the latter is the role of the scoping graph. Examples showing why E-matching
|
|
is defined the way it is would be particularly useful.
|
|
</p>
|
|
|
|
<p>
|
|
Because of the problems I see in Section 2, I do not feel that I can adequately
|
|
understand the remainder of the document.
|
|
</p>
|
|
<p>
|
|
Because of these problems I do not feel that this document should be advanced
|
|
to the next stage in the W3C recommendation process without going through
|
|
another last-call stage.
|
|
</p>
|
|
</blockquote>
|
|
|
|
<p>Our <a href="http://www.w3.org/mid/1143049602.12963.360.camel@dirk.w3.org">response of 22 March</a> is:</p>
|
|
|
|
<blockquote>
|
|
<p>
|
|
After perhaps overly brief consideration of your comments, we are
|
|
somewhat sympathetic to your concerns about organization and
|
|
clarity; however, we also have schedule considerations
|
|
and the investment in other reviewers. Re-organizing the document
|
|
at this stage would delay things considerably; it's not even clear
|
|
that we could get a sufficient number of reviewers to take another
|
|
look before CR.
|
|
</p>
|
|
|
|
<p>
|
|
The specific examples you give below are very valuable; I
|
|
am marking this thread [needstest], which allows us to find
|
|
it more easily during CR and integrate the examples you give
|
|
into our test suite. We have also discussed the possibility
|
|
of significant organizational changes after CR, such as
|
|
moving the formal definitions to the back of the document.
|
|
</p>
|
|
|
|
<p>
|
|
As far as I can tell, all of the examples you give are useful
|
|
clarification questions, but they do not demonstrate design errors.
|
|
If they do, in fact, demonstrate design errors, I'm reasonably
|
|
confident we will discover that as we integrate them into
|
|
our test suite during CR.
|
|
</p>
|
|
|
|
<p>
|
|
Are you, by chance, satisfied by this response, which does
|
|
not involve making the changes you request at this time,
|
|
but includes an offer to give them due consideration after
|
|
we request CR? If not, there's no need to reply; I'm marking
|
|
this comment down as outstanding dissent unless I hear otherwise.
|
|
</p>
|
|
</blockquote>
|
|
</li>
|
|
|
|
<li>On 5 March, Elliotte Harold asked that we <a
|
|
href="http://lists.w3.org/Archives/Public/public-rdf-dawg-comments/2006Mar/0006.html">don't
|
|
use ? and $. Pick one.</a> He was not satisfied by our attempts to
|
|
justify our decision as part of <a href="http://www.w3.org/2001/sw/DataAccess/issues#punctuationSyntax">punctuationSyntax issue</a>:
|
|
<blockquote>
|
|
<pre>
|
|
> >> A number of design considerations were laid out in:
|
|
> >> <a href="http://lists.w3.org/Archives/Public/public-rdf-dawg/2004OctDec/0160">Draft: open issues around '?' use.</a>
|
|
> >>
|
|
>
|
|
> I think this makes some good arguments for using a $ instead of a ?.
|
|
> However it doesn't convince me that using both is a good idea. Why are
|
|
> two characters considered necessary here? Why not just pick the $ and be
|
|
> done with it?
|
|
|
|
The use of ?var syntax in SPARQL goes back all the way to the <a href="http://www.w3.org/TR/2004/WD-rdf-sparql-query-20041012/">1st
|
|
WD in October 2004</a>
|
|
|
|
The number of reviewers, users, and implementors that we would need
|
|
to collaborate with in order to take ?var out is considerable, and
|
|
it's not clear that we have an argument that is sufficient to convince
|
|
them. True, allowing both adds various costs, but this is largely
|
|
sunk cost. The details of the specification are worked out; we have
|
|
test cases and multiple implementations. A growing number of users
|
|
have learned the ?var syntax, and those that need to use ODBC-style
|
|
systems seem to know about and be happy with $var.
|
|
It seems unlikely that we would get consensus around a change
|
|
to take out ?var or $var in a reasonable amount of time, and the
|
|
number of parties that are interested to see SPARQL advance to
|
|
Candidate Rec soon is considerable.
|
|
|
|
Again, please let us know whether you find this response satisfactory.
|
|
</pre>
|
|
</blockquote>
|
|
</li>
|
|
</ol>
|
|
|
|
</div>
|
|
|
|
<address>
|
|
Dan Connolly, <a href="./">RDF Data Access Working Group</a> chair, 22 March 2006<br/>
|
|
<small>$Revision: 1.35 $ of $Date: 2006/04/04 16:09:12 $</small>
|
|
</address>
|
|
|
|
|
|
<hr />
|
|
<div><h2>Ammendments</h2>
|
|
|
|
<p>Changes since <a
|
|
href="http://lists.w3.org/Archives/Public/public-rdf-dawg/2006JanMar/0470.html">email
|
|
proposal of 21 Mar 2006 18:27:57 -0600</a>:</p>
|
|
|
|
<pre>
|
|
$Log: crq349.html,v $
|
|
Revision 1.35 2006/04/04 16:09:12 connolly
|
|
Network Inference/Cerebra withdraws their
|
|
objection to the Result Limits requirement
|
|
in a message of Fri, 31 Mar 2006 18:04:07 -0800
|
|
|
|
Revision 1.34 2006/03/29 13:05:35 connolly
|
|
a link to "obj" fixed to "#obj"
|
|
most recent protocol spec is Jan 2006, not Jan 2005
|
|
tx Ivan
|
|
|
|
Revision 1.33 2006/03/27 14:09:16 connolly
|
|
disjuction objection withdrawn (see w3c-archive)
|
|
|
|
Revision 1.32 2006/03/22 18:24:31 connolly
|
|
found a form of confirmation of XQuery/XSL WG satisfaction
|
|
|
|
Revision 1.31 2006/03/22 18:12:58 connolly
|
|
moved status at top to signature at bottom
|
|
|
|
Revision 1.30 2006/03/22 18:10:50 connolly
|
|
noted PFPS's comments of 22 Mar under outstanding dissent,
|
|
and noted our attempt to seek consensus within schedule constraints
|
|
|
|
Revision 1.29 2006/03/22 18:04:02 connolly
|
|
clarify which features are related to outstanding
|
|
dissent on Data Integration and Aggregation
|
|
|
|
Revision 1.28 2006/03/22 17:06:08 connolly
|
|
- added changelog
|
|
|
|
- re-phrased the record of WG decision
|
|
|
|
- distinguished proposed status with blockquote, grey, border
|
|
|
|
- matched brackets around "tune to each part"
|
|
- ...has stabilized +and+ the...
|
|
- +An+ implementation report...
|
|
- spellcheck: language, sustained, remaining, diligent,
|
|
satisfaction (x2), abstaining, entailment
|
|
|
|
</pre>
|
|
</div>
|
|
|
|
</body>
|
|
</html>
|