- From: Jim Hendler <hendler@cs.umd.edu>
- Date: Sun, 13 Jun 2004 23:34:41 -0400
- To: Dirk-Willem van Gulik <dirkx@asemantics.com>
- Cc: "Seaborne, Andy" <andy.seaborne@hp.com>, public-rdf-dawg@w3.org
At 21:44 +0200 6/13/04, Dirk-Willem van Gulik wrote: >On Jun 8, 2004, at 2:51 PM, Jim Hendler wrote: > >> I think you missed the intent of my message - I tried to be >>clear that I was NOT talking about an open ended query -- I would >>not be going to CYC and saying tell me what you know about cats, I >>would be going to a graph and querying forthe bindings for a query >>something like this >..snup.. >> Query the CYC graph for the pattern in which cat has a >>CLASSTYPE (subclassof or equivalentClass) >> of a restriction class and return to me the names of what >>PROPerties the restriction is on, what OWLterm the restriction uses >>(AllValues, SomeValues, etc.) and what the RESTriction is. >..snup.. >> In practice I might do something different than this (perhaps >>multiple queries for specific combinations as I needed them), but >>in every case I am asking for specific properties of specific >>entities from an RDF graph - in my opinion, this capability is why >>I devoted so much of my past few years to making OWL an RDF >>language -- if I just wanted to query documents, I would have >>agreed that an XML syntax was sufficient -- but for linking and >>processing OWL, I want to use the URIs and the graph >... >> As far as 3.6 goes, I guess I could use optional features in the >>above, I was thinking of multiple queries myself, but could go >>either way ... > >Query, and returning a (partial) tree from a certain point on is one >thing - Querying multiple times as in "over -time-" and/or as the >result of a previous query and looking at the aggregate result set >is quite another - as you then suddenly are into transactions, >locking and consistancy issues if the database is live; i.e. changes >under your feet. > >Sofar the emphasis on a 'one query' one answer has very much >reasures me - and stayed well away of the usual rat holes. > >Dw I wasn't talking about multiple queries over time - although these are slow changing documents in the main so it woudln't worry me - I meant submitting multiple query patterns for each of the things I wish to check for -- thus, if a new foaf implementation wants to know if, for example, DNA-Checksum is owl:inverseFunctional or not, that's just a single query for a single result -- which is why this use case is important, it reminds people that dereferencing RDFS (and OWL) relations is basically just an RDF query - which is a major benefit of RDFS -- Professor James Hendler http://www.cs.umd.edu/users/hendler Director, Semantic Web and Agent Technologies 301-405-2696 Maryland Information and Network Dynamics Lab. 301-405-6707 (Fax) Univ of Maryland, College Park, MD 20742 240-277-3388 (Cell)
Received on Sunday, 13 June 2004 23:35:02 UTC