Inference Reqults according to DBPedia Ontology

Hi, 


I am creating a local RDF store, and storing some information in it myself. 

For example, 

- "Angela Merkel is a Chancellor" 
- "Barack Obama is a President"

In DBPedia ontology it is stated that, 

Chancellor is subclass of Politician. President is also subclass of Politician.

When I make a SPARQL query to my local RDF store, I want to get inference result according to DBPedia
OWL ontology. 


In this case, if I ask give me all politicians, it should give me -
Angela Merkel and Barack Obama.

My Question: Should I keep a copy of DBPedia ontology in my RDF store? Or what else could I do?

Thanks.