- From: Dan Brickley <danbri@w3.org>
- Date: Tue, 18 Mar 2003 16:31:20 -0500
- To: eric@w3.org
- Cc: www-rdf-rules@w3.org
Eric, I'm reviewing http://www.w3.org/2001/11/13-RDF-Query-Rules/ Rather than try to prepare a single detailed review, I'm sending separate msgs on particular bits as and when I grab time to do this. If you'd rather I tried to make a more unified review doc, I could do that. The current approach seemed a quicker way to make gradual progress... So first thing I wanted to ask about: Under "Goal Characteristics", you distinguish... [[ graph or arc Some languages express a single arc, others an open subgraph. No observed single arc languages support variables. This leaves them unable to answer the specific query represents(?x ?x) "What lawyers represent themselves?" but instead the more general question represents(?x ?y) "What lawyers represent anybody?". At this point, all single arc query languages are outside the scope of this survey. ]] This paragraph makes me curious. You rule discussion of these languages out of scope, and don't cite any. Are they a theoretical rather than actual possibility? In my experience 'single arc' functionality is only exposed via RDF APIs, rather than textually represented query languages. I don't know of any actual 'single arc' query syntaxes, though perhaps some of the path-oriented efforts might fall under this heading? Your claim that "No observed single arc languages support variables" would carry more oomph if you listed some observed single arc languages. Can you give examples? Even if for the purposes of ruling them out of scope for detailed analysis. If there aren't any, this is probably worth noting. Dan ps. you also have "some languages" in the first entry, and "some query engines" in the second, under "Goal Characteristics". Are you comparing query languages or software designs / implementations? (these have tended to be 1:1 in recent history, I guess...). My assumption is that the focus here is on language comparison.
Received on Tuesday, 18 March 2003 16:31:20 UTC