- From: Eric Prud'hommeaux <eric@w3.org>
- Date: Tue, 18 Mar 2003 16:56:57 -0500
- To: Libby Miller <Libby.Miller@bristol.ac.uk>
- Cc: Dan Brickley <danbri@w3.org>, www-rdf-rules <www-rdf-rules@w3.org>
On Tue, Mar 18, 2003 at 09:39:13PM +0000, Libby Miller wrote: > > I think Versa might be one of these 'single arc' types - see > http://uche.ogbuji.net:8080/uche.ogbuji.net/tech/rdf/versa/versa.doc?xslt=/ftss/data/docbook_html1.xslt > > and especially > http://uche.ogbuji.net:8080/uche.ogbuji.net/tech/rdf/versa/versa-by-example.txt > > Libby Versa and TAP were my only examples. Beyond that, the obvious wrapping of a serialization protocol around an API. > On Tue, 18 Mar 2003, Dan Brickley wrote: > > > > > 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". fixed - tx > 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. languages, mostly there's a section for implementation characteristics [1] http://www.w3.org/2001/11/13-RDF-Query-Rules/#implChar -- -eric office: +1.617.258.5741 NE43-344, MIT, Cambridge, MA 02144 USA cell: +1.857.222.5741 (eric@w3.org) Feel free to forward this message to any list for any purpose other than email address distribution.
Received on Tuesday, 18 March 2003 16:57:01 UTC