On 06/01/12 18:32, Olivier Rossel wrote:
[Sorry for the cross post on jena-dev@yahoogroups]
my raw problem is this: i get airport informations from talis sparql
endpoint (for example, the town of the airport).
and now i also want the icon of the town of the airport.
i can get that info from dbpedia
but i am not sure talis endpoint supports SERVICE.
so i want my jena client to do the SERVICE trickery by itself
and i wish i could express this business requirement into one single query
(which is the point of a federated query).
so, basically, i need one single local query with two separate service
calls to talis and dbpedia.
(i DO NOT want two separate queries (one for airport infos, one for
town icons) plus java code to glue things together)
is there a way to do that with jena?
You can have a query like ...
SELECT ...
{
SERVICE <talis>
{
...
}
SERVICE <dbpedia>
{
...
}
}
Note: i think darq or semwiq could have helped but they are not
maintained anymore.
Yes - the SERVICE feature is "basic federated query". It's a building
block which gives you call-out, but it is not a complete solution that
chooses the best order based on remote stats.
Andy
