As other monks have suggested, the term "high traffic" is very subjective. However, I would say there is plenty of streamlining that you can do. Without knowing more about your site, it's my inclination to say that you can probably sub-divide your site, regenerating your more frequently visited pages regularly, but not dynamically (by a background process, for example). By the same token, those pages that haven't been accessed in a while can also be shelved, simply by applying whatever templates you may have and outputting static HTML. It's a delicate process...unfortunately, every webmaster really has to judge for themselves how much is too much, and that generally requires carefully examining traffic logs. In any case, good luck.

-Mike-