W3C home > Mailing lists > Public > public-rdf-dawg@w3.org > July to September 2010

Re: 4 MINUS and NOT EXISTS test cases

From: Chimezie Ogbuji <ogbujic@ccf.org>
Date: Mon, 19 Jul 2010 12:59:19 -0400
To: "Andy Seaborne" <andy.seaborne@talis.com>
cc: "SPARQL Working Group WG" <public-rdf-dawg@w3.org>
Message-ID: <C869FCA7.1278C%ogbujic@ccf.org>
I've committed these tests into the CVS (all but the last one, which I
cannot reconcile with the behavior of Minus - see below):

RCS file: 
Working file: manifest.ttl
head: 1.1
locks: strict
access list:
symbolic names:
keyword substitution: kv
total revisions: 1;    selected revisions: 1
revision 1.1
date: 2010/07/19 16:38:23;  author: cogbuji;  state: Exp;

On 7/5/10 5:49 PM, "Andy Seaborne" <andy.seaborne@talis.com> wrote:
> ..snip ..
> I don't agree with this.
> The matching part of the MINUS is:
> { ?otherExam a ex:PhysicalExamination; dc:date ?otherExDT } gives:
> and then the FILTER:
> FILTER(?date<  ?otherExDT&&  ?otherExDT<  ?opDT)
> uses ?date which is out of scope for the clause MINUS so the FILTER is
> error always so nothing matches for MINUS {}

Hmm, I've been staring at this test for a while and cannot determine an
alternative.  This query is meant to implement an exclusion criteria that
rules out the possibility that there is a physical examination that is
closer to the operation (based on lexical ordering of the associated dates),
so any resulting ?exam binding should be the 'closest' examination prior to
the operation.  

However, in order to use the MINUS operator in the same way the EXIST
operator was used in the previous test, I would essentially need to use
?exam as the join condition between the LHS and RHS.  It doesn't seem
possible to use it for this kind of problem since the Minus algebra operator
is defined such that the operands are independent of each other:

Minus(Ω1, Ω2) 
= { μ | μ in Ω1?
    such that for all μ' in Ω2, either μ and μ' are not compatible or dom(μ)
and dom(μ') are disjoint }

Am I missing something?

I have left this particular test out.

-- Chime


P Please consider the environment before printing this e-mail

Cleveland Clinic is ranked one of the top hospitals
in America by U.S.News & World Report (2009).  
Visit us online at http://www.clevelandclinic.org for
a complete listing of our services, staff and

Confidentiality Note:  This message is intended for use
only by the individual or entity to which it is addressed
and may contain information that is privileged,
confidential, and exempt from disclosure under applicable
law.  If the reader of this message is not the intended
recipient or the employee or agent responsible for
delivering the message to the intended recipient, you are
hereby notified that any dissemination, distribution or
copying of this communication is strictly prohibited.  If
you have received this communication in error,  please
contact the sender immediately and destroy the material in
its entirety, whether electronic or hard copy.  Thank you.
Received on Monday, 19 July 2010 17:00:03 UTC

This archive was generated by hypermail 2.3.1 : Wednesday, 7 January 2015 15:01:01 UTC