Namespaces in queries, part 2

One of the nice things about blogging is that you get people to review your ideas, for free.

Yesterday I claimed that you don’t need URI prefixes in RDF queries. Instead of writing this:

PREFIX foaf: <http://xmlns.com/foaf/0.1/>
PREFIX doap: <http://usefulinc.com/ns/doap#>
SELECT DISTINCT ?projectName ?personName
WHERE { 
  ?person foaf:name ?personName .
  ?person doap:project ?project .
  ?project doap:name ?projectName .
}

one could write this:

SELECT DISTINCT ?projectName ?personName
WHERE {
  ?person :name ?personName .
  ?person :project ?project .
  ?project :name ?projectName .
}

and have the undeclared default namespace match any namespace in the data. It’s shorter, it’s more readable, no more hunting around for copy and pasting those namespace URIs, what’s not to like?

Well, everybody hates the idea. See the comments to the piece linked above, and Ora’s rant and comments there. So I’m probably wrong.

I found most of the cited reasons pretty lame though, ranging from dogma to tortured SQL analogies to performance concerns. Some good bits:

Evan:

Lumping [properties from different namespaces] together should only be done if the user explicitly specifies that it should be done,

Spot on: an optional, well-defined and compact way for specifying that the user wants them lumped together. That’s what I want.

and it is likely there would be far more accidental collisions than purposeful collisions.

I disagree about the prediction, but it’s hard to prove either way.

Richard Newman:

I assume the proposal is just the fevered ramblings of a man sick of writing

PREFIX foaf: <http ://xmlns.com/foaf/0.1/>

every time he wanted to query on names.

My answer: environment support.

While Richard may be quite right about my motivation, I don’t see environment support happening. SPARQL is usually entered into web forms, text editors and IDEs. I’m not aware of any support in any of these environments (well, except in D2R Server (example)), and I’m not going to wait two years for a solution.

Ora and drewp pointed out that, if I don’t want to query for full URIs, I should query for rdfs:labels. That’s a good point. A query language that lets me do

SELECT ?personName ?projectName WHERE
?project a project .
?project name ?projectName .
?project developer ?person .
?person name ?personName .
?person a person .

would indeed be cool. This would be halfways between SPARQL and NLP projects like Ginseng. The downside is that one would have to design an all-new language, and apart from the namespace issue, I like SPARQL just fine.

Danny mentioned microformats, where namespaces are unnecessary because the community has to agree on a schema before it can be used. But I don’t want to change anything on the data side; URIs for properties and classes are great. That doesn’t necessarily mean we need to do the same on the query side.

Finally, Henry:

I think you just posted this to get attention ;-)

Uh, no. Though it certainly worked ;-)

A question to those still interested in the discussion: 100% of widely deployed RDF vocabularies follow the convention of namespace plus mnemonic local parts. Why is it wrong to exploit a universally accepted convention in a query language?