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Re: RDQL functionality vs. DAWG requirements

From: Eric Prud'hommeaux <eric@w3.org>
Date: Tue, 29 Jun 2004 07:04:58 -0400
To: public-rdf-dawg@w3.org
Message-ID: <20040629110458.GF20261@w3.org>
Oh, and kudos to Yoshio for discovering my mistakes.

On Tue, Jun 29, 2004 at 06:55:01AM -0400, Eric Prud'hommeaux wrote:
> On Tue, Jun 01, 2004 at 11:23:51PM +0900, Eric Prud'hommeaux wrote:
> > 
> > Persuant to my action item to review RDQL with respect to the
> > requirements [1] from the 25-May 2004 teleconference [2], I evaluated
> > (and implemented) RDQL per the Jan 2004 W3C submission [3].
> > 
> > I was planning on getting this out later this week, but earlier is
> > probably better than better. Besides, Andy will fix it all up for me.
> > 
> > I copped Bryan's convention [4] for reporting requirement support:
> > 
> >      rdql+ : rdql supports this requirement today under a suitable
> >  	     protocol binding and/or query language.
> > 
> >      rdql- : the requirement appears to be explicitly outside of the
> > 	     scope of rdql, which is not to say that it could NOT be
> > 	     met by a suitable revision of rdql.
> > 
> >      rdql? : need more information to make the determination.
> > 
> > This somewhat contrived example query will serve as a syntactic
> > example of how RDQL meets the requirements:
> > 
> >   SELECT ?family , ?given
> >   FROM   <http://example.org/JohnzVcard.rdf>
> >   WHERE  (?vcard  vcard:FN "John Smith")
> >          (?vcard  vcard:N  ?name)
> >          (?name   vcard:Family  ?family)
> >          (?name   vcard:Given  ?given)
> >          (?name   vcard:age  ?age)
> >          (?name   vcard:shoeSize  ?shoeSize)
> >   AND    ?shoeSize > 5
> >   AND    ?age >= ?shoeSize
> >   USING  vcard FOR <http://www.w3.org/2001/vcard-rdf/3.0#>
> > 
> > Requirements:
> > 
> > rdql+ : 3.1 RDF Graph Pattern Matching
> >   WHERE  (?vcard  vcard:FN "John Smith")
> >          (?vcard  vcard:N  ?name)
> >          (?name   vcard:Family  ?family)
> >          (?name   vcard:Given  ?given)
> > 
> > rdql+ : 3.2 Variable Binding Results 
> >   SELECT ?family , ?given
> >   From the spec: [[
> > The variable "?x" will be bound to the label of the subject resource.
> > All such "x" are returned
> > ]]
> > 
> > rdql- : 3.3 Extensible Value Testing
> >   Has support for equality and comparison operators for integers.
> 
> Oops, seems likely that STR_MATCH and STR_NMATCH provide regexp
> support:
> 
> StringEqualityExpression
>  ::=  	ArithmeticCondition ( 
>     <STR_EQ> ArithmeticCondition 
>   | <STR_NE> ArithmeticCondition 
>   | <STR_MATCH> PatternLiteral 
>   | <STR_NMATCH> PatternLiteral )*
> 
> 
> > rdql- : 3.4 Subgraph Results
> > 
> > rdql+ : 3.5 Local Queries
> >   The specification does not describe the result format or mechanism,
> >   however, an API implementation of this protocol would be able to
> >   perform local queries.
> > 
> > rdql- : 3.6 Optional Match
> > 
> > rdql+ : 3.7 Limited Datatype Support
> >   AND    ?shoeSize > 5
> >   AND    ?age >= ?shoeSize
> > 
> > rdql- : 3.8 Bookmarkable Queries
> >   RDQL does not spcify a canonicalization into a local part of a URI.
> > 
> > rdql+.5 : 3.9 Bandwidth-efficient Protocol
> >   Query protocol is terse and easy on the eyes. No result protocol is
> >   defined.
> > 
> > rdql- : 3.10 Result Limits
> > 
> > Design Objectives:
> > 
> > rdql+ : 4.1 Human-friendly Syntax
> >   RDQL queries read like a sentence. They allow the use of
> >   qnames. Term-enclosing parens could be replaced by a single
> >   delimiter ala N3, but I it is, in my opinion, easy on the eyes.
> > 
> > rdql- : 4.2 Provenance
> > 
> > rdql- : 4.3 Non-existent Triples
> > 
> > rdql- : 4.4 User-specifiable Serialization
> >   RDQL does not specify results format/protocol nor provide syntax to
> >   select such.
> > 
> > rdql- : 4.6 Aggregate Query
> 
> I believe I mis-remembered what this requirement was about. At some
> point, during face to face one, we discussed aggregating the subgraph
> of supporting statements from each result. That is NOT what Aggregate
> Query is about. I suspect there's a wording problem in Aggregate
> Query (separate mail), but think that RDQL does support it.
> 
> > rdql- : 4.6 Additional Semantic Information
> > 
> > 
> > [1] http://www.w3.org/2001/sw/DataAccess/UseCases
> > [2] http://www.w3.org/mid/--lost-my-copy-of-the-minutes
> > [3] http://www.w3.org/Submission/2004/SUBM-RDQL-20040109/
> > [4] http://www.w3.org/mid/D24D16A6707B0A4B9EF084299CE99B39053F8C01@mcl-its-exs02.mail.saic.com
> > -- 
> > -eric
> > 
> > office: +1.617.258.5741 NE43-344, MIT, Cambridge, MA 02144 USA
> > cell:   +1.857.222.5741
> > 
> > (eric@w3.org)
> > Feel free to forward this message to any list for any purpose other than
> > email address distribution.
> 
> -- 
> -eric
> 
> office: +81.466.49.1170 W3C, Keio Research Institute at SFC,
>                         Shonan Fujisawa Campus, Keio University,
>                         5322 Endo, Fujisawa, Kanagawa 252-8520
>                         JAPAN
>         +1.617.258.5741 NE43-344, MIT, Cambridge, MA 02144 USA
> cell:   +1.857.222.5741 (does not work in Asia)
> 
> (eric@w3.org)
> Feel free to forward this message to any list for any purpose other than
> email address distribution.



-- 
-eric

office: +81.466.49.1170 W3C, Keio Research Institute at SFC,
                        Shonan Fujisawa Campus, Keio University,
                        5322 Endo, Fujisawa, Kanagawa 252-8520
                        JAPAN
        +1.617.258.5741 NE43-344, MIT, Cambridge, MA 02144 USA
cell:   +1.857.222.5741 (does not work in Asia)

(eric@w3.org)
Feel free to forward this message to any list for any purpose other than
email address distribution.

Received on Tuesday, 29 June 2004 07:04:59 GMT

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