The data model is designed to save as much space as possible and to implement every detail in the RDF and schema specification. I am planning to solve the speed problem with intelligent use och caching and maby even second order databases, generated from the core database. In a big RDF database, there will be lots of indirect resources. These resources doesn't have to be stored as separate records in the resource table. If that is the case, they are taken to be local recources.
Every statement is in it self a resource.
The statement is represented as a resource in the way used with reified statements. That is the role of the FACT field. My conclusion is that even the internal literals can be thought of as resources. The RDF spec makes a very clear distinction between literals and resources. But it makes for much more symetry if you could store the URI content in the literal.