- From: Damian Steer <pldms@mac.com>
- Date: Tue, 02 Sep 2008 23:24:53 +0100
- To: Richard Newman <rnewman@twinql.com>
- Cc: Semantic Web at W3C <semantic-web@w3.org>
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 2 Sep 2008, at 22:15, Richard Newman wrote: > One issue I have encountered in the past is that a query like > > SELECT * { > GRAPH ?g { > ?s foo:bar ?baz ; > zob:zab ?bing . > } > FILTER (allowed(?g)) > } > > will only return answers where *both* triple patterns match in the > same permitted graph. That seems fairly obvious to me, but you're right that the named graph store + access control I mentioned looks like a triple store but really isn't because of this case. For our use case it doesn't matter, happily. > > SELECT * > FROM <allowed-1> > FROM <allowed-2> > ... > WHERE { > ?s foo:bar ?baz ; > zob:zab ?bing . > } > > but that means the query is specific to the user (or you have to use > out-of-band dataset selection). This is one of the reasons we aren't FILTERing graphs in the query. Probably a premature optimisation, but they make life more rewarding. > A couple of years ago I was working on a system that very heavily > used very complex access control. My ultimate conclusion was that > standard SPARQL was not very well suited to this kind of thing. > That's an interesting conclusion for a SPARQL implementor to draw, > but there you are :) Are any query languages suited to this? Damian -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.8 (Darwin) iEYEARECAAYFAki9vTUACgkQAyLCB+mTtyk4kQCg+1jFG7R85sLcMuCnfCczPvvi dwYAnAuB/odovRgK/8zZAfZSEta9dft6 =rcGm -----END PGP SIGNATURE-----
Received on Tuesday, 2 September 2008 22:25:45 UTC