- From: Henry Story <henry.story@bblfish.net>
- Date: Thu, 12 Dec 2013 18:27:28 +0100
- To: Linked Data Platform WG <public-ldp-wg@w3.org>
Part 3 of Issue-89 creates a relation ldp:propertiesOnlyResource to allow an LDPC to point in its header to the "membership properties". The reason for this is to avoid so called duplication of triples. The duplication of triples is an issue mostly for the ldp:DirectContainer as is visible for a container such as the following <> a ldp:DirectContainer; ldp:containerResource <>; ldp:containsRelation m:manages; ldp:xyz <doc1>, <doc2>, <doc3> ; m:manages <doc1>, <doc2>, <doc3> . ( I am using ldp:xyz for what alexander in ISSUE-89 calls ldp:contains. You can replace it without loss here and throughout this e-mail. ) But according to the rule such as the one used in the Membership wiki [1] it would be very easy to determine the "membership triples" using only the ldp:xyz relations PREFIX ldp: <http://www.w3.org/ns/ldp#> CONSTRUCT { ?subject ?predicate ?object } WHERE { ?ldpc a ldp:DirectContainer; ldp:containerResource ?subject; ldp:containsRelation ?predicate; ?ldpc ldp:xyz ?document . BIND (?document AS ?object) # the POSTed resource is the member } UNION { ?ldpc a ldp:DirectContainer; ldp:containerResource ?object; ldp:containedByRelation ?predicate. # ldp:containedByRelation is used ?ldpc ldp:xyz ?document . BIND (?document AS ?object) } } In that case duplication is not a problem at all, since a client could just infer the "membership triples" from the ldp:xyz ones using that query. On the other hand if such a rule is not true, and cannot be written out, then there is no duplication, since the "membership triples" are in fact different triples, and have no necessary relation to the ldp:xyz ones. But then this does give one a good reason for having them in a different possibly server managed resource. [1]in the Membership wiki "Determining the membership triples to be added when a new member is created" http://www.w3.org/2012/ldp/wiki/Membership#Determining_the_membership_triples_to_be_added_when_a_new_member_is_created Social Web Architect http://bblfish.net/
Received on Thursday, 12 December 2013 17:28:04 UTC