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I went to Edinburgh last week for WWW2006.

I spent Tuesday in the workshop on Identity, Reference, and the Web (IRW2006). I didn't really finish my presentation slides in time, but I think my paper, A Pragmatic Theory of Reference for the Web is mostly coherent. Each section of the workshop got an entry in a semantic wiki; mine is the one that started at 12:00.

The IRE formalism presented by Valentina and Aldo was though-provoking. I think their proxy-for is like foaf:topic (modulo the way they mix in time). And exact-proxy-for is like foaf:primaryTopic. Very handy. I wonder if foaf:primaryTopic should be promoted to its own thing, separate from all the social networking stuff in foaf.

Ginsberg's talk hit on one of the most important questions: "Do I commit to a document just because I use one of its terms?" His answer was basically to reify everything; I think we can do better than that. Peter Patel-Schneider's talk basically gave a 'no' answer to the question. I don't think we should go that far either, though from a standardization point of view, that's sorta where we're at.

Steve Pepper's talked about published subjects and public resource identifiers; I can sympathize with his point that we have too many URL/URI/URN/IRI/XRI/etc. terms, but when he suggests that the answer is to make a new one, I'm not sure I agree. He argues to deprecate all the others, but as URI Activity lead at W3C, I'm not in a position where I can overrule people and deprecate things that they say they want. I agree with him that the 303 redirection is too much trouble, but he doesn't seem to be willing to use the HashURI pattern either, and as I said in the advice section of my paper, that's asking for trouble.

On Thursday, I was on a panel about tagging versus the Semantic Web: Meaning on the Web: Evolution or Intelligent Design?. Frank started by debunking 4 myths about the Semantic Web. I gotta find Frank's slides. "I'll hold up one finger whever anybody says myth #1, and so on." As the the other Frank was talking about tagging, Frank held up 2 and 3 fingers, and the audience pointed out that he should have held up 1 finger.

I talked without slides. I think I got away with it. I said that I don't expect symbolic reasoning to beat statistical methods when it comes to the wisdom of crowds, but who wants to delegate their bank balance or the targets of their mail messages to the wisdom of crowds? Sometimes we mean exactly what we say, not just something close.

I suggested that GRDDL+microformats is a practical way to get lots of Semantic Web data. And I brought up the problem with iCalendar timezones and noted that while timezones data should be published by the government entities that govern them, Semantic Web data from wikipedia might be a more straightforward mechanism and might be just as democratic.

So much for philosophical discussions; stay tuned for another item about SPARQL and databases and running code.

The developer track at WWW2006 last week in Edinburgh was really cool; you had to show up on time or you couldn't fit in the room! One of the coolest talks was D2R-Server - Publishing Relational Databases on the Web as SPARQL-Endpoints.. I see D2R Server is released now. Cool.

Yes, storing RDF in a SQL database using 3-column tables (or 4 or 5 or 6...) is cool as far as it goes, but I'm gland we're finally seeing more work on taking existing SQL databases (whose schemas are not designed with RDF in mind) and exporting them as RDF.

TimBL wrote a design note on Relational Databases on the Semantic Web in 1998. In 2002, I wrote dbview.py, a couple hundred lines of python that implements parts of it. Rob Crowell picked it up and the 2005/2006 version of dbview.py now does foreign keys and backlinks.

D2R gets points for using RDF for their configuration/mapping info. The slides showed turtle/n3. Why are the dbin brainlets in XML but not RDF? I wonder.

D2R Server has a mapping layer; dbview assumes that will be handled with rules. The choice of URIs for column names is interesting. D2R uses jdbc:mysql://127.0.0.1/wordpress#users1, but dbview is all about embedding a SQL database in HTTP space, so we use URIs like http://db.example/orders/customers/custno/1#item. In dbview, the decisions about when to use / and when to use # are made so that the result is browseable. In D2R, the default URIs don't matter as much because it's expected that they'll be mapped to a more well-known ontology/schema like foaf.

dbview is still just a few hundred lines of python; we haven't integrated the SPARQL parser that Yosi developed for cwm, nor integrated EricP's work on federated query.

Speaking of federated query... on Wednesday at the conference, I saw Tim Finin in the poster session. He showed me something the swoogle folks are cooking up: you give it a SPARQL query, and it looks at the terms used in your query and suggests documents you should put in your SPARQL dataset to run your query against. I hope to hear more about that.

Somewhere in EricP's work is one of the several SPARQL-to-SQL rewriters out there... oh... I thought the HP tech report, A relational algebra for SPARQL was another one, but it seems to be by Richard Cyganiak, one of the D2R guys.

Benjamin Nowack's Feb 2006 item announced a SPARQL-to-SQL rewriter for his ARC RDF store for PHP.

Hmm... maybe it's time for a ScheduledTopicChat on SPARQL, SQL, and RDF? If you're interested, suggest a couple times that would be good for you in a comment or in mail to me and a public archive.