Dear all, I need to know about the possibility of making queries on a Wikibase instance. I think it is possible to make queries on data on a particular instance only with external tools at the moment, right?

On 29.04.2015 20:56, Luca Martinelli wrote: Yes, this is correct. The SPARQL query support that we currently offer is obtained by making an RDF export and loading it into a SPARQL database (we use Virtuoso but you could also use BlazeGraph, for example; both have free and open source versions and are not hard to install overall; if your data is not so large, you could also try Jena; there are further open source RDF databases, but these are the most prominent right now I think). The RDF export, too, is not currently generated by Wikibase. However, Wikidata Toolkit, which we use to make the RDF dumps, can be used with data from any Wikibase installation in theory. In practice, nobody has asked for this yet and we might have to make a few adjustments to really get it to work in a convenient way. For a start, I don't know what kind of export options a standalone Wikibase offers you at the moment. We can use the usual XML-based page dump if it contains valid JSON for a change (this was not the case for Wikidata last time I checked ...). Better yet would be the JSON exports, but I don't know if you can generate them with vanilla Wikibase or if WMF is using some special tools for this. Anyway, it can't be too hard to make this work and once it is done you would have a query service that is at the same level as the one of Wikidata. You could even combine data from more than one Wiki in one RDF database, e.g., to run queries over data from both. Regards, Markus _______________________________________________ Wikidata-l mailing list Wikidata-l(a)lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikidata-l

On 30.04.2015 11:25, Jean-Baptiste Pressac wrote: Maybe not your computer, but somebody has to download the data in some way in order for it to be queried. Query answering is a complicated process that does not usually work on the fly, and somebody has to do the math in the end. There are some approaches to explore linked data in a query-like manner in real time, but it should be clear that this will always take much longer than if you have downloaded the data first. This is still a useful thing to do for several reasons. First of all, the link connects your data and clarifies its meaning. This is useful to consumers who find your data. Second, there are linked data crawlers that aggregate linked data from many sources to provide you with a query service. OpenLink is running one such service, and if they managed to find your data, you could use their service to issue queries. Regards, Markus _______________________________________________ Wikidata-l mailing list Wikidata-l(a)lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikidata-l