I'm tackling a similar, albeit simpler problem, with my dynamic region loader for my coordinate based MUD. Full world data will be something on the order of 100GB, (well, I'd like to be able to support such sizes at least - it may take a while to create that much of the world with content, though :P). Obviously having all of that in RAM at once will be a bit of an issue :P.
edit - er, this is solely in response to the post above mine. My problem set only resembles the megatexture in regards to the dynamic loading issue.
edit - er, this is solely in response to the post above mine. My problem set only resembles the megatexture in regards to the dynamic loading issue.