On 27/01/13 15:30, Sarven Capadisli wrote:
Hi,
Is it possible to run a single Fuseki server with multiple TDB datasets
such that the queries span over those datasets?
The short answer is "no".
The long answer is that a union dataset could be developed that gave a
dataset view of 2+ sub-datasets. It would not be able to push down full
queries so there are performance implications at scale but for many uses
it might be useful.
SERVICE is the nearest it gets.
(But why not use one dataset with careful named graphs? You can use GSP
(Graph Store Protocol) to manage data which is convenient.
For instance, a query performed at service A/query (with dataset A) may
also contain results from dataset B. And vice-versa if query performed
at service B/query.
I realize that it may be a bit too much to ask for something like this
(and probably not possible), but my idea was to use separate databases
so that I can update them independently with a lot of flexibility,
meanwhile having the SPARQL endpoint(s) see all of the data without the
need for federated queries.
What happens (= what does it mean) if both datasets have the same named
graph?
If I use the same fuseki:name for each fuseki:Service, the last one
takes over and the query result reveals data only from its dataset.
The names have to be different. Probably should have been a
warning/error if there is reused (patches welcome!).
Thanks,
-Sarven
You'll be wanting datasets-of-datasets next!
Andy
http://csarven.ca/#i
