- From: Kingsley Idehen <kidehen@openlinksw.com>
- Date: Thu, 01 Jul 2010 12:43:29 -0400
- To: Kingsley Idehen <kidehen@openlinksw.com>
- CC: Yves Raimond <yves.raimond@gmail.com>, nathan@webr3.org, Pat Hayes <phayes@ihmc.us>, Toby Inkster <tai@g5n.co.uk>, Dan Brickley <danbri@danbri.org>, Linked Data community <public-lod@w3.org>, Semantic Web <semantic-web@w3.org>
Kingsley Idehen wrote:
> Yves Raimond wrote:
>> Hello!
>>
>>
>>>>> IMHO an emphatic NO.
>>>>>
>>>>> RDF is about constructing structured descriptions where "Subjects"
>>>>> have
>>>>> Identifiers in the form of Name References (which may or many
>>>>> resolve to
>>>>> Structured Representations of Referents carried or borne by
>>>>> Descriptor
>>>>> Docs/Resources). An "Identifier" != Literal.
>>>>>
>>>>> If you are in a situation where you can't or don't want to mint an
>>>>> HTTP
>>>>> based Name, simply use a URN, it does the job.
>>>>>
>>>>>
>>>> It does look like you're already using literal subjects in OpenLink
>>>> Virtuoso though:
>>>>
>>>> http://docs.openlinksw.com/virtuoso/rdfsparql.html
>>>>
>>>> SQL>SELECT *
>>>> FROM <people>
>>>> WHERE
>>>> {
>>>> ?s foaf:Name ?name . ?name bif:contains "'rich*'".
>>>> }
>>>>
>>>> Best,
>>>> y
>>>>
>>>>
>>>>
>>> Were is the Literal Subject in the query above?
>>>
>>
>> ?name is a literal. And it is used as a subject.
>>
>
> Yves,
>
> Here's why its deemed magic/function/unreal predicate (a function
> selectively working on literal data associated with the URI):
>
> 1. http://bit.ly/cQJTWQ -- SPARQL Query Results Page
> 2. http://bit.ly/acQc4u -- Actual SPARQL Query
>
> There isn't an actual Literal Subject in the Virtuoso RDF DBMS. The
> RDF_QUAD Table explicitly has Column "S" set to type IRI.
>
> Here is the actual SQL DML for RDF_QUAD:
** SQL DDL (Data Definition Language construct) *** not DML.
>
> create table "DB"."DBA"."RDF_QUAD"
> (
> "P" IRI_ID,
> "S" IRI_ID,
> "O" ANY,
> "G" IRI_ID,
> PRIMARY KEY ("P", "S", "O", "G")
> );
>
>
> Kingsley
>
>
>> Best,
>> y
>>
>>
>>> bif:contains is a function/magic predicate scoped to Literal Objects.
>>>
>>> <people> != "people".
>>>
>>> What am I missing?
>>>
>>> --
>>>
>>> Regards,
>>>
>>> Kingsley Idehen President & CEO OpenLink Software Web:
>>> http://www.openlinksw.com
>>> Weblog: http://www.openlinksw.com/blog/~kidehen
>>> Twitter/Identi.ca: kidehen
>>>
>>>
>>>
>>>
>>>
>>>
>>
>>
>
>
--
Regards,
Kingsley Idehen
President & CEO
OpenLink Software
Web: http://www.openlinksw.com
Weblog: http://www.openlinksw.com/blog/~kidehen
Twitter/Identi.ca: kidehen
Received on Thursday, 1 July 2010 16:44:16 UTC