- From: <bugzilla@jessica.w3.org>
- Date: Tue, 26 Oct 2010 14:21:35 +0000
- To: public-qt-comments@w3.org
http://www.w3.org/Bugs/Public/show_bug.cgi?id=11147 Summary: [XQuery11] The rule for rewriting nondeterministic function calls is too strict Product: XPath / XQuery / XSLT Version: Working drafts Platform: All OS/Version: All Status: NEW Severity: normal Priority: P2 Component: XQuery 1.1 AssignedTo: jonathan.robie@redhat.com ReportedBy: josh.spiegel@oracle.com QAContact: public-qt-comments@w3.org Group: XSLXQuery_WG The following statement is in section 4.18 Function Declaration: "When rewriting expressions into equivalent expressions, as described in 2.3.4 Errors and Optimization, a conforming XQuery implementation must ensure that each run-time invocation of a nondeterministic function in the original expression results in exactly one run-time invocation of the function in the rewritten expression." This statement seems too strict. An optimizer should be able to eliminate nondeterministic function calls that do not contribute to the results of the expression. For example, consider this query: let $x := f() return 27 Even if f() is nondeterministic, it seems OK for an optimizer to rewrite this expression as 27. Note, this issue has be discussed previously [1]. One suggestion was to change the wording as follows [2]: "If a non-deterministic function call contributes to the results of an expression, a conforming XQuery implementation must ensure that every result is generated by a new invocation of the function." [1] http://lists.w3.org/Archives/Member/w3c-xsl-query/2010Jul/0169.html [2] http://lists.w3.org/Archives/Member/w3c-xsl-query/2010Jul/0192.html -- Configure bugmail: http://www.w3.org/Bugs/Public/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are the QA contact for the bug.
Received on Tuesday, 26 October 2010 14:21:37 UTC