The RGMAStorageLocation structure holds file or database connection details for a Primary or Secondary Producer. It is filled in by hand then passed into the constructor for the producer. Naming your own database (via the location, username and password fields) is deprecated - you should assign a logical name instead (via the logicalName field), then call RGMAPrimaryProducer_listTupleStores() to retrieve the name of the database created by R-GMA.