Anybody ever heard of Netezza? I was told about it by someone who works with vast amounts of data - many terabytes every day. It's part of a hardware system that uses overwhelming processor power to segment and blast through data. You don't need the traditional headers or relational database structures to search like this. The technology is costly now (it's specialized hardware) but if you want to talk about where databases are going beyond the relational, this is one direction.