using module as fact store

Hi, I've come to a situation where the data my application is processing is in unit of database. For example, I want to transform a world into another, where both worlds are described in the form of a database.
 Naturally the first approach I thought about is simply using dynamic modules to represent databases, but soon I find:
 Enumerating facts is troublesome(especially in my application the fact types supported may not be statically determined)--I have to use stuff like current_predicate and clause, and the fatal thing is that, current_predicate may enumerate predicates not defined by my application(system predicates that may be autoloaded), thus makes this approach less attractive.
 Is the module system in SWI prolog suitable for this situation?
 PS: The way I'm taking now(mainly to temporarily work around this) is refactoring w:f(x) into w:fact(f(x)), and then do w:fact(F) to get all facts. This is quite clean and straight to my expection but it introduces a meta layer.
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