If you're using a utility (e.g., Jena's rdfcat
to concatenate the RDF documents, then you have nothing to worry about. Prefixes just make reading and writing a little easier, but RDF-aware tools don't really care. If being able to concatenate data with text-based tools (i.e., tools that aren't RDF-aware) is important, then you should probably use the N-Triples format. It is very simple, just
subject predicate object .
with one triple per line. Since there is no provision for prefixes, text concatenation simply works. N-Triples also has the (even nicer) feature that if you need to split up a document, e.g., for distributed processing, you can just split the file, as long as you split at linebreaks. That's impossible with N3, RDF/XML, and other more complicated formats.