I think it would be easier to do then you might think. Since all of the database interaction is handled via a class in a self contained file, and the way its called is basically by taking a name from your config file (the one with your sql server, password, database, etc. in it) it might be possible to simple rewrite the existing functions so you would be left with the same functionality, but it would be utilizing a different class, and hence a different database. using the current class as a blueprint, basically.

i've thought about this many times as some of vb's db interaction really hits my server performance. i have a fairly large board, and especially searching can litterally hang the server. the only thing thats kept me from giving it a go, is the fact i cant really afford the oracle software :P

hell i can barely afford my cell phone bill with banner ads paying what they are :P

note: you'd need some kind of parser for the queries themselves :\