- From: Giovanni Tummarello <g.tummarello@gmail.com>
- Date: Thu, 12 Jul 2007 11:27:07 +0100
- To: www-tag@w3.org
- Cc: Eyal Oren <eyal.oren@deri.org>
Greetings, these days a discussion broke out on the Linking Open Data on the Semantic Web mailing list (community project of the SWEO internet group) about the perceived need to revise the http-range-14 outcome. Chris suggested that we refer to this group be contacted. The issue we see is that 303 is an unfortunate return code for semantic web URIs as the HTTP specs state that such responses MUST NOT be cache. This can be easily seen as having very negative consequences on implementations (e.g. the only way to speed up processing of rdf files would be to patch web proxies and/or browsers to violate the standard). It appears to some that there could be alternative solutions which do not have this problem and, most of all in my opinion, do not use redirection. Redirection has in fact very confusing side effects; as we expect the semantic web to work seamlessly with the web, it is very odd that a semantic web uri cannot be copy pasted to a browser without seeing it change to something that is not the same as before. This is highly confusing and can lead to errors.. e.g. copy pasting it from the browser to send it for reference in a email or IM or to a semantic web client would result in the wrong URI be used (when instead the right one was previously pasted in the browser). Alternative solutions that have been proposed include codes in both the 20x series and 40x, in particular code 203 "non authoritative" clarifies that the information that is being served does not necessarely correspond to the original resource, might be a subset or a superset. For a human this is ok, a machine could clarify that it is in fact a non informative semantic web resource by asking for an RDF version via content negotiation. An appropriate 40x code would be even more explicit in this sense. Some related mails with more details [1][2] [3] To conclude, the semantic web of http retrievable data is now really happening, but we are absolutely still in time to correct this issues early so they don't bite back in term of architectural problems (the caching issue) and serious complexity/confusion for the end users (the rewrite). Sincerely Giovanni [1] Eyal Oren "caching HTTP 303 responses" http://lists.w3.org/Archives/Public/semantic-web/2007Jul/0078.html [2] Giovanni Tummarello "203,400, 406 as alternative to 303 ?" http://simile.mit.edu/mail/ReadMsg?listName=Linking%20Open%20Data&msgId=18630 [3] Fred Giasson "Eurostat data about countries and regions " http://simile.mit.edu/mail/ReadMsg?listName=Linking%20Open%20Data&msgId=18194
Received on Thursday, 12 July 2007 10:27:13 UTC