Hi all,

I am trying to get the Apache Jena UnionModel working for my scenario, but I 
keep encountering unexpected behavior. I’ve set up a minimal, free-standing 
example on github in this repository (clone the git repo, configure Maven in 
your IDE and execute the main() method, I.e. it probably does not run from the 
.jar):

 https://github.com/barrynl/jena-example



I have two questions related to this example:

My first question is related to empty graphs in Jena Fuseki. If I load the 
conf.ttl (from the git repo above) at startup in Apache Jena Fuseki without the 
dummy data in the two named graphs, the two graphs seem to disappear (I think 
this does not happen in my Java Example). I read somewhere that empty graphs 
are automatically deleted in Fuseki to prevent old graphs from showing up in 
the Fuseki interface. For my use case I would like to configure two (possibly 
empty at first) named graphs via a conf.ttl and be able to store data in them 
afterwards. Is this possible?

My second question is about the demonstraded behaviour of the Java example in 
the git repository above. I load a dataset with a UnionModel from a conf.ttl 
file and insert new data in it via SPARQL. Although the new data shows up in 
the select query, it does not show up in either of the two names graphs the 
UnionModel consists of. My question is: where is this data stored if not in one 
of the names graphs? (If I inspect the UnionModel via a debugger, the inserted 
data DOES show up in the correct named graph)

Hopefully someone can shed some light on this behaviour. Thanks in advance!

Regards, Barry
This message may contain information that is not intended for you. If you are 
not the addressee or if this message was sent to you by mistake, you are 
requested to inform the sender and delete the message. TNO accepts no liability 
for the content of this e-mail, for the manner in which you use it and for 
damage of any kind resulting from the risks inherent to the electronic 
transmission of messages.

Reply via email to