- From: Eric Prud'hommeaux <eric@w3.org>
- Date: Mon, 21 Jun 2004 14:54:16 -0400
- To: "Seaborne, Andy" <andy.seaborne@hp.com>
- Cc: public-rdf-dawg@w3.org
- Message-ID: <20040621185416.GF20051@w3.org>
On Mon, Jun 21, 2004 at 12:13:44PM -0400, Eric Prud'hommeaux wrote: > On Mon, Jun 21, 2004 at 04:06:23PM +0100, Seaborne, Andy wrote: > > > > Eric, > > > > The extensibility mechanism is by naming a feature set in the query. I > > think having named sets of features is a good idea, rather than always > > having just a feature-by-feature naming. It might be useful to be able to > > enquire of a query processor what feature sets it supports. Just for yucks, I implemented this as a profile. So there's a profile that you can use for querying profiles. (Sorry 'bout the long namespace) Q: ns pq=<http://lists.w3.org/Archives/Public/public-rdf-dawg/2004AprJun/0699.html#> require pq:profileQuery profileQuery(pq:profileList ?p) collect (?p) A: +---------------------------------------------------------------------------------------+ | p| |---------------------------------------------------------------------------------------| | <http://www.w3.org/2004/05/06-Algae/#core>| | <http://www.w3.org/2004/06/20-rules/#assert>| |<http://lists.w3.org/Archives/Public/public-rdf-dawg/2004AprJun/0699.html#profileQuery>| +---------------------------------------------------------------------------------------+ The code is in the latest Federate at http://www.w3.org/1999/02/26-modules/dist/Federate-1.tar.gz > > There seem to be two usages: > > > > 1/ Want to ensure a number of queries can be executed, the early ones may > > not need a given extension so the app wants to knowion advance it wil be OK. > > To do this, it needs to ask before a query is submitted. > > Good point. That technique could be used to identify server that can > or will do inferencing for you. > > > 2/ In any given query, it is only the fetaures actually used that matter, > > not the whole set (if named). In this case, can't the query processor > > detemine which features are needed simply by parsing the request? If so, > > then there is some neatness in declaring features but it isn't necessary is > > it? Or do required features modify the query/results in some way? > > My main goal was to make sure a query server would know if it > understood a request. Two folks could invent the "assert" action (say > one took statements in n3 and another expected p s o) and the server > would either not know which to expect or not even know that there > *was* another one out there. > > There may be mutually exclusive extensions. Perhaps the client > wouldn't have thought a lot about its query and not reallize that > there were some conflicts, but I bet it would be apparent to the > person developing the server code. These requests would get a response > from the server indicating the conflict and the client would have to > think harder about what they were trying to ask.. > > Less importantly, maybe some proxy can do something clever with a > cursory parsing of the query without knowing the full semantics of all > the extensions. But then, maybe not. > > > -------- Original Message -------- > > > From: Eric Prud'hommeaux <> > > > Date: 21 June 2004 08:59 > > > > > > I've done a bunch of thinking over the weekend about extensibility and > > > how it interacts with streamability. I've prototyped a solution in > > > algae. > > > Take a peek at the Algae doc on profiles and extensibility [1] and an > > > extension (implemented, but poorly documented at this point) on adding > > > rules to query [2]. It uses and demonstrates the extensibility > > > mechanism. > > > > > > [1] http://www.w3.org/2004/05/06-Algae/#extensibility > > > [2] http://www.w3.org/2004/06/20-rules/ > > -- > -eric > > office: +81.466.49.1170 W3C, Keio Research Institute at SFC, > Shonan Fujisawa Campus, Keio University, > 5322 Endo, Fujisawa, Kanagawa 252-8520 > JAPAN > +1.617.258.5741 NE43-344, MIT, Cambridge, MA 02144 USA > cell: +1.857.222.5741 (does not work in Asia) > > (eric@w3.org) > Feel free to forward this message to any list for any purpose other than > email address distribution. -- -eric office: +81.466.49.1170 W3C, Keio Research Institute at SFC, Shonan Fujisawa Campus, Keio University, 5322 Endo, Fujisawa, Kanagawa 252-8520 JAPAN +1.617.258.5741 NE43-344, MIT, Cambridge, MA 02144 USA cell: +1.857.222.5741 (does not work in Asia) (eric@w3.org) Feel free to forward this message to any list for any purpose other than email address distribution.
Received on Monday, 21 June 2004 14:54:16 UTC