[siscia]

It really depends on what you are building.

If I were building a fast prototype I would not use a postgres box anymore but just a redis one.

If you need to cache data in a way more complex than just key->value you don't have too many alternatives at the moment.

If you want an easy and fast way to have an SQL engine in memory, again is not going to be simple.

If you need a separated database for every of your user there are no many alternatives that I am aware of.

It is definitely not a revolutionary product, but it has it's niche, any of the problems that I mentioned can be solved in a different way, but those different ways are quite complex.