Wikidata/Development/RDF: Difference between revisions

Revision as of 19:36, 3 August 2012

Revision as of 19:51, 3 August 2012

Line 182:

=== Named graphs ===

GivingAdding a claimreference to a referenceclaim can be done in three ways:

* put every claim in one file and then add provenance metadata about that file

*# put every claim in aone named graphfile and then add provenance metadata about that graphfile

*# reifyput every claim soin thata wenamed cangraph and then add provenance metadata directlyabout to thethat claimgraph

*# putreify every claim inso onethat filewe and thencan add provenance metadata aboutdirectly thatto filethe claim

Ad 1: Having one file for every claim would lead to many files. Even if you are conservative and expect about only ten statements per item, resolving that item would require ten or more HTTP requests. This is prohibitively slow, especially considering that they are all very small files that we are requesting. It also would lead to an unreasonable amount of load on the server, something MediaWiki is not very well equipped for (a server based on [http://nodejs.org/ Node.js] or [http://twistedmatrix.com/trac/ Twisted] would probably be much better equipped for that, though).

Ad 2: The file holding all statements about an item could also contain a named graph for every single claim and then add metdata about these graphs, like the references. Whereas this could be a solution, there is, as of time of writing, no standard for the serialization of named graphs in files. There are a number of contenders (TriX, TriG, NQuads, etc.), but none of them is even on the way of becoming a standard.

Ad 3: See the section on reification below.

=== Quads ===