MongoDB or Redis ?
I've heard that I should keep collections small in MongoDB to enable better indexing (and indexes fitting on RAM), and I've heard that redis is "blazing fast" but MongoDB is better if you have bigger collections.
What's the most efficient one if I have multiple thousand collections of say a few thousand of hashes ?
I'm asking this because in my project it's too early to have available data to benchmark and I would probably design bad benchmark scripts because I don't understand very well the theoretical concepts of those two database engines, specially Redis.
Thanks for everyone who answers this.