Not arguing with the rest of your post, but what would you write a large-scale DBMS with, these days? Surely not jpython?
But maybe, just maybe, I would first connect Oracle's prodigious moneyduct into a team writing a kick-ass Lisp compiler and then writing the best RDBMS using Lisp.
One can dream...
What I had in mind was that for anyone who is technically capable of maintaining the core Oracle DB code base, there are more interesting and rewarding things they could be doing instead.
Then I would use a more programmer friendly language on top of that. Something like Scheme, Ruby, Python and the like.
Stratified design, basically.
I am not sure about Haskell, but, from my limited experience, Erlang runs at levels very close to C (my C, at least)
http://shootout.alioth.debian.org/u32/which-programming-lang...