[antirez]

I agree in general, SQL is like magic (this is why it can't scale). You write abstract tables and then automatically you can do incredible queries against it, and this is very cool indeed.

But there are some kind of problems that Redis can fix in a very natural way. For example the idea of PUSH and LRANGE solves the get-last-N-items problem in a trivial way compared to MySQL.

Also Set intersection is able to solve tagging easily compared to the complex queries needed in a SQL db.

So SQL is very flexible, but strangely enough some trivial data access pattern is hard to model and slow even if it is as direct as take the last N items from a list.