Actually I could do it with SQL, key-value store, and even with document stores, not to mention Erlang's Mnesia (whichever category it falls into). I think wit

Actually I could do it with SQL, key-value store, and even with document stores, not to mention Erlang's Mnesia (whichever category it falls into). I think without understanding the complete picture, write patterns, read patterns, number of open connections etc. it is hard to say it is definitely SQL.