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Re: Free-text search and SPARQL New Features and Rationale draft

From: Kjetil Kjernsmo <Kjetil.Kjernsmo@computas.com>
Date: Mon, 6 Jul 2009 16:32:16 +0200
To: "Chris Bizer" <chris@bizer.de>
Cc: public-rdf-dawg-comments@w3.org
Message-Id: <200907061632.16853.Kjetil.Kjernsmo@computas.com>
Chris,

On Friday 03 July 2009 17:05:03 Chris Bizer wrote:
> How are the chances that one of these functions will be free-text search?

I am afraid they are very slim at this point, as Lee said, the WG gave it 
careful consideration and it fell just outside. I was the main champion of 
free-text search in the working group, and we spend quite a lot of time on it 
on the face-to-face, where I defended it violently,  to the extent that I 
ended up attacking the OWL entailment feature (which I certainly see as 
useful), as I figured the only way to get freetext in was that OWL Entailment 
had to go out of the time-permitting list.

Now, I think that the overall progress of the working group is important, so 
we will not raise a formal objection over this matter, but if the community 
at large decides to cry "what were you thinking?", I will be sympathetic to 
their voices. :-) Myself, I regard it a lost battle for now.

>Today, people have to use dirty hacks like FILTER regex(?label, "%word1%") 
>to emulate free text search. 

Indeed. Several different approaches were discussed, including XPath/XQuery 
freetext, which the group felt were overkill for us.

In an attempt to make the requirements more manageable, I suggested that we 
only support the typical website "search box", i.e. a freetext search that 
consists of a few words, that may or may not be truncated, may or may not be 
combined with AND and OR. The WG noted that these requirements could all be 
met by the hacks you described above, and rather than introducing a possibly 
large and risky feature, one should instead use the freetext indexing engine 
to optimize certain regexp queries. I have allready posted a feature request 
for this in Virtuoso:
https://sourceforge.net/tracker/?func=detail&aid=2796431&group_id=161622&atid=820577

Also, we have noted that the main cost of migrating from one SPARQL backend to 
another was the way freetext search is dealt with in different systems. This 
is a problem for SPARQL.

So, this is where it stands from my perspective. 

Kind regards 

Kjetil Kjernsmo
-- 
Senior Knowledge Engineer / SPARQL F&R Editor
Mobile: +47 986 48 234
Email: kjetil.kjernsmo@computas.com   
Web: http://www.computas.com/

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Received on Monday, 6 July 2009 14:32:45 GMT

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