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RE: querying reacheability using RDQL

From: Seaborne, Andy <andy.seaborne@hp.com>
Date: Wed, 8 Sep 2004 11:55:10 +0100
Message-ID: <8D5B24B83C6A2E4B9E7EE5FA82627DC96969@sdcexcea01.emea.cpqcorp.net>
To: "Alessandro Di Bella" <aldib@fuurou.org>
Cc: <www-rdf-interest@w3.org>

Query expressions in RDQL are of fixed length so, no, you can't write an
arbitrary reachability query.

One way it can happen is if the source provides inference and there is
some super property which is transitive.  Then it is just a matter of
asking (?x :p ?y).

An example would be rdfs:subClassOf.

Do you have a concrete use case for this requirement?  The RDF Data
Access Working group is working on a query language and it is gathering




From: www-rdf-interest-request@w3.org
[mailto:www-rdf-interest-request@w3.org] On Behalf Of Alessandro Di
Sent: 7 September 2004 16:18
To: www-rdf-interest@w3.org
Subject: querying reacheability using RDQL

Is it possible to query the reachability of a resource from another?
For example, given the triples:

t1, cxn1, t2
t1, cxn2, t3
t2, cxn3, t4
t5, cnx4, t6

can i execute a query that says: 

select all individuals  that can be reached from t1 

and that returns

t2 (direct arc)
t3 (direct arc)
t4 (indirect arc through t2)



Received on Wednesday, 8 September 2004 10:55:44 UTC

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