Re: ACTION-133, ISSUE-22

* Richard Cyganiak <richard@cyganiak.de> [2011-06-21 16:03+0100]
> 
> 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?

I think this is less dire than you express (many of the above extended protocols only defined a single identifier), but I'm happy to take a micro-formats wiki approach. Any reason this shouldn't be on the RDB2RDF wiki?


> > 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 lot 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.

I'm content to use the predicates rr:sqlVersion and rr:sqlQuery
because it doesn't really break anything and it may be slightly easier
for SQL users (the overwhelming majority of our clients) to understand
the directives. Ivan, What do you think (noting that this is sort of a
process question).


> Oh and one more point: We need to settle wether languageIdentifier/sqlVersion can be multi-valued.

Yeah, I've been mulling that over in my head. I guess all of the use cases which motivate an identifier motivate n identifiers.

> Best,
> Richard

-- 
-ericP

Received on Tuesday, 21 June 2011 17:10:37 UTC