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RE: Innovation, community and queries

From: Margaret Green <mgreen@nextance.com>
Date: Fri, 31 May 2002 16:13:25 -0700
Message-ID: <458473676F1AC74A84EAB2F22004DA6D0BF63C@mail.nextance.com>
To: "Danny Ayers" <danny666@virgilio.it>
Cc: <www-rdf-interest@w3.org>

Hi Danny, et al,

As I lurk here reading about query of RDF, I see allusions to needs, 1)
interoperability, 2) queries themselves saved as resources (a string of
SQL could be thought of as a literal), 3) strong types ...  ---
Certainly identifying requirements and use cases are important useful
exercises in describing a problem space. But I think a more fundamental
examination should precede those exercises.

I would like to see a discussion that examines what it means to compose
and execute a query over a forest of graphs asserted as triples. Is it
the graphs that are the output of the query? Is it the journey of
traversal over the selected graphs (a graph walker) that a processor of
query results takes? Is it a set of triples that are the output? Are new
graphs formed by assertions created by the reasoning implicit in the
query? 

By its nature RDF is a different beast and our database notions formed
from use of a language SQL to query a model, the relational model, don't
all necessarily fit. 

Just as there is nothing new under the sun, I'm sure these questions
have been engaged over the course of many threads and by the
implementers of over a half dozen RDF query languages. But have they
been engaged as a whole? And isn't it about time to try?


Hungry for query,
Margaret Green



-----Original Message-----
From: Danny Ayers [mailto:danny666@virgilio.it] 
Sent: Friday, May 31, 2002 2:22 PM
To: Uche Ogbuji; Seaborne, Andy
Cc: 'Patrick Stickler'; ext Thomas B. Passin; RDF Interest
Subject: RE: Innovation, community and queries 



>properties(@"x:spam")
>@"x:spam" - properties() -> *

Another good reason for an RDF QL in RDF!

Seriously though, I do think such a QL would be extremely useful, not
only
because it would generally help interop.  It would also mean that a
whole
range of common expressions could become easier in RDF (without having
to
drop into DAML-land), and also make things like XSLT-ish transformations
a
lot more straightforward. Not unrelated to the interop point, the
ability to
save sets of queries in a common format like RDF/XML has to be a plus -
same
parser etc etc.

Cheers,
Danny.
Received on Friday, 31 May 2002 19:17:01 GMT

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