If you don't need a terabyte of data stored, just use an in-memory data structure, and have 1 server process in whatever language you're using, and manipulate w

If you don't need a terabyte of data stored, just use an in-memory data structure, and have 1 server process in whatever language you're using, and manipulate whatever you would do in memory, and work from there. Maybe SQL is the right choice, maybe not, but you'll at least have a better idea of the problem space that you're interested in.