I wanted to join in and give my birthday present to Wikidata (I am a
little bit late, though!)
(also, honestly, I didn't recall it was Wikidata's birthday, but it is
a nice occasion :P)
Here it is:
What is LDF?
LDF stands for Linked Data Fragments, they are a new system for query
RDF datasets that stands middle way between having a SPARQL endpoint
and downloading the whole thing.
More formally LDF is «a publishing method [for RDF datasets] that
allows efficient offloading of query execution from servers to clients
through a lightweight partitioning strategy. It enables servers to
maintain availability rates as high as any regular HTTP server,
allowing querying to scale reliably to much larger numbers of
This system was devised Ruben Verborgh, Miel Vander Sande and Pieter
Colpaert at Multimedia Lab (Ghent University) in Ghent, Belgium.
You can read more about it: http://linkeddatafragments.org/
What is Wikidata LDF?
Using the software by Verborgh et al. I have setup the website
* an interface to navigate in the RDF data and query them using the
Triple Pattern Fragments client
* a web client where you can compose and execute SPARQL queries
This is not, strictly speaking, a SPARQL endpoint (not all the SPARQL
standard is implemented and it is slower, but it should be more
reliable, if you are interested in details, please do read more at the
The data are, for the moment, limited to the sitelinks dump but I am
working towards adding the other dump. I have taken the Wikidata RDF
dumps as of Oct, 13th 2014.
To use them I had to convert them in HDT format[3a][3b], using the
hdt-cpp library[3c] (devel) (which is taking quite a lot of resources
and computing time for the whole dumps, that's the reason why I
haven't published the rest yet ^_^).
DBpedia has also this:
All the software used is available under the MIT license on the LDF
repo on github[5a], and also the (two pages) website is available
I would like to thank Ruben for his feedback and his presentation
about LDF at SpazioDati in Trento, Italy (here's the slides).
All this said, happy birthday Wikidata.
[5a] see the Browser.js, Server.js and Client.js repos in