Hi,
Well your question should be posted to BW forum rather than to BPC forum. As far as I know, SAP BW supports most of the db, oracle, DB2, MS SQL Server, etc.There is entire data modelling cycle which will need to be followed to create BW cubes, etc. to get the data in BW from your underlying database.
You may want to read more about BW data modelling. BPC has no role to play yet.
Regards,
Ashish