I'm currently learning the MEAN stack (and just started learning web development a few months ago) and I'm using mongoDB/mongoose as a post storage database. The project I'm working on is basically a 4chan-like image board with tags. I'm not expecting it to go public, but if it did it shouldn't have more than maybe 20,000 posts at a time.

I want to do something like stack overflow does where they have a pop-up come up when users start typing tag names. Does anyone know if redis would be suitable for this or have a suggestion for something even better? Keep in mind I'm trying to stay away from really advanced databases and would prefer a noSQL solution.