Re: What would break, a question for implementors? (was Re: Is 303 really necessary?)

On 11/5/10 9:13 AM, bill.roberts@planet.nl wrote:
>
> Hi Nathan - thanks for clear answer. I see the point and also the 
> argument for using hash URIs with ontologies.
>
> In practice how I get round this prob is to preload my triple store 
> with the handful of common ontologies I know I'm going to use, so 
> don't need to deref them as I go along.
>
> Cheers
>
> Bill
>

Bill,

What happens when the ontologies evolve?


Kingsley
>
>
>
> -----Original Message-----
> From: Nathan [mailto:nathan@webr3.org]
> Sent: Fri 11/5/2010 1:12 PM
> To: bill.roberts@planet.nl
> Cc: public-lod@w3.org; Dan Brickley
> Subject: Re: What would break, a question for implementors? (was Re: 
> Is 303   really necessary?)
>
> bill.roberts@planet.nl wrote:
> > Hi Nathan
> >
> > I'm not saying you're wrong - but could you explain why it would be 
> a pain for FOAF terms to return 200?  Which kinds of application are 
> dereferencing those terms and relying on a 303 response?
> >
> > eg http://xmlns.com/foaf/0.1/Person currently 303s to 
> http://xmlns.com/foaf/spec/
> >
> > What would break if http://xmlns.com/foaf/0.1/Person returned that 
> same content with a status code of 200?
> >
> > Just trying to understand the issue
>
> Hi Bill,
>
> Good question :)
>
> If you consider a basic linked data client, with a basic ontology/schema
> awareness, for instance one which shows peoples FOAF profiles and uses
> the nice rdfs:label's for properties rather than "foaf:Person".
>
> It's going to have to GET the ontology, now when it cycles through the
> properties it'll find http://xmlns.com/foaf/0.1/Person and GET it, then
> hopefully cache it against the URL specified in the [content?] location
> of the final request (be that 1 or many requests). When you 200 OK the
> response then the ontology will be stored against
> http://xmlns.com/foaf/0.1/Person so when you hit
> http://xmlns.com/foaf/0.1/knows you need to do another GET, and be
> returned a full ontology again, thus you end up with 40+ requests with
> full responses and 40+ cached versions of the single ontology. Unless
> you code around it in some way, make a provision for FOAF.
>
> However, if you use 303's the then first GET redirects there, then you
> store the ontology against the redirected-to URI, you still have to do
> 40+ GETs but each one is fast with no response-body (ontology sent down
> the wire) then the next request for the 303'd to URI comes right out of
> the cache. It's still 40+ requests unless you code around it in some
> way, but it's better than 40+ requests and 40+ copies of the single
> ontology.
>
> The above, together with the deployment for FOAF is a v good reason
> *not* to use slash URIs for ontologies - ask Dan Bri about the FOAF
> rewrite rules for a second opinion on that :p
>
> Hope that explains,
>
> Best,
>
> Nathan
>


-- 

Regards,

Kingsley Idehen	
President&  CEO
OpenLink Software
Web: http://www.openlinksw.com
Weblog: http://www.openlinksw.com/blog/~kidehen
Twitter/Identi.ca: kidehen