A quick follow up to my Views in Triple Stores posting.
Andrew Newman describes how my requirements can be addressed within Kowari. He also noted (privately) that views are crucial for lots of use cases, pointing me at this thread on kowari-general.
Richard Cyganiak was less keen on the idea. He's right that too wide a depth would pull in too much data, but you get the same problem with a "SELECT * FROM..." query. Just don't do it!
I'm also don't understand Cyganiak's comment on my suggestion to use namespaces as a means to filter predicates: Namespaces are just that, namespaces. Don’t overload them with access control. I'm not sure how he's using the term "access control" here, that's not what I was suggesting. And namespaces are intended to partition vocabularies, so not using them as a way to ignore data that's not of interest seems bizarre to me.
His note that filtering by data isn't addressed is fair, but I didn't include that as I'd counted that as part of the initial query to finding the initial node(s) of interest, not the construction of the "view".
Must admit I've not looked at CONSTRUCT (or indeed Sparql at all yet) so maybe that does address some of what I'm interested in (and I have a real-world application in mind: this is a real use case).
One additional filtering criteria, which would rely on the use of named graphs,
would be to filter by origin. i.e. "only return me data from these trusted sources."