How to use a dataset for multiple ontologies

[robbie clifford]

I have a number of ttl files that I am loading into an oracle SDB.At the moment 
I am loading them all into the default model
e.g. 
Store store = SDBFactory.connectStore(sdbConnection,storeDesc);Model model = 
SDBFactory.connectDefaultModel(store);model.read(inputStream, null, 
format.getName());
Should I be using a Dataset with named models to keep the ontologies separate?I 
cannot figure out how to do this.
ThanksRobbie