Thanks for all the suggestions folks! After posting the original question and reading all the responses, and thinking more about the situation, I've decided to push harder for the SQL idea (we have an Oracle server, so power to spare!) One thing holding me back here was the problem with the size of the database; we might be limited to keeping the size down under a gig or so, but people do occasionally request stats for the deep distant past, which is in those flat files (currently).

I want to make the interface transparent not only to the user, but to *me* as the programmer, as much as possible (except, of course, for speed!) but now that I have seen the DBD::RAM module I have more hope of writing an abstraction layer. We'll store the older data in DBM files (or stick with the current flat files) and access those through the DBD::RAM module which gives us an SQL frontend into that data.

Is it conventional to say "omm" at this point? =)