Hi,
Acknowledging that I've missed the original deadline for the call for suggestions, and so it might not get
considerd, I wanted to raise this additional suggestion with the working group (it'll at least get recorded
somewhere).
Feature:
Extended DESCRIBE
Feature Description:
Currently it is left undefined as to how a SPARQL processor should generate the results of a
DESCRIBE query. There are several possible algorithms that might be applied, and these are useful in
different contexts. It would be useful to be able to specify an algorithm in the SPARQL query, so that
the client has additional control over the form of the results.
Algorithms would be referred to be URI. The specification may define zero or more of these, and implementations
might converge on a standard set.
Example
I'd envisage something like:
DESCRIBE ?x WHERE {
?x a foaf:Person.
}
USING <
http://www.example.org/closure/concise-bounded-desc>
...where USING refers to a standard URI for the algorithm used to describe the results.
Existing Implementations
I believe Virtuso has a similar feature using query pragmas.
Use Cases
Provide more control over form of DESCRIBE query results on the client. It is not always possible to achieve the
same effect with a CONSTRUCT query due to other limitations in the language (e.g. in graph traversal, container
construction, etc). Even if those issues were resolved there are advantages in the coarse grain style of query that
this feature provides.
Cheers,
L.
--
Leigh Dodds
Programme Manager, Talis Platform
Talis
leigh.dodds@...http://www.talis.com
