- From: Richard Cyganiak <richard@cyganiak.de>
- Date: Tue, 21 Jun 2011 16:03:13 +0100
- To: Eric Prud'hommeaux <eric@w3.org>
- Cc: W3C RDB2RDF <public-rdb2rdf-wg@w3.org>, Michael Hausenblas <michael.hausenblas@deri.org>
On 21 Jun 2011, at 15:43, Eric Prud'hommeaux wrote: >> 3. It should say at least a sentence on where identifiers for other languages may come from. > > I had deliberately left that information out because I didn't want to predict. Precedent indicates that sometimes these are strongly associated with a registry (as with the shortnames for XPointer registration schemes), defined by later revisions of standards (XHTML namespaces), invented by external organizations (as WS-1 did with SOAP-related identifiers) or invented by interested parties in the community (like most RDF identifiers or XML Signature's *Method identifiers). It's quite a cop-out. As an implementer, what am I supposed to do if my implementation does special handling of a non-SQL-2008 dialect? There are some constraints (e.g., don't mint a new term in the w3.org/TR/r2rml namespace) as well as some guidance that we can give (e.g., look up some place to see if someone else minted an appropriate ID already). Not saying anything is lazy and doesn't serve users or implementers well. Can we operate a registry of SQL version IDs? Even if it's just a wiki page? > Here's an example which relies on algebra syntax: > _:subjMap1 rr:languageIdentifier <http://...relationalAlgebra> ; > rr:queryString "π ID,addr,city (People) ⋈ σ state="MA" Addresses" . > > Critical? no. > Useful? could be. There are a log of things that would be useful, but are out of scope. So is this one. If implementers want to use R2RML with relational algebra syntax, and have to do it this way: _:subjMap1 rr:sqlVersion <http://...relationalAlgebra> ; rr:sqlQuery "π ID,addr,city (People) ⋈ σ state="MA" Addresses" . then yeah that's a mild form of abuse, but it *works* and that's good enough IMO, given that we don't have a requirement to actually support this kind of use. Oh and one more point: We need to settle wether languageIdentifier/sqlVersion can be multi-valued. Best, Richard
Received on Tuesday, 21 June 2011 15:03:59 UTC