Affordable and efficient. Affordable in what sense precisely? There are open source and free options everywhere. Or do you mean "affordable with a certain leve

Affordable and efficient. Affordable in what sense precisely? There are open source and free options everywhere. Or do you mean "affordable with a certain level of traffic?" as in a hosted solution? Efficient in what sense precisely? All databases are efficient but not magically so. You'll need to read the documentation and learn about indexing and the specific write/read characteristics of your choice. With where it seems are you currently, I don't actually think those things matter. I'd say ease of use - sqlite has everything beat hands down, but I also wouldn't actually suggest it for a production system if you're hoping to have a bit of traffic. * Postgres is good * Mariadb is good * Mongodb is good Personally I'd choose Postgres, but I see the advantages of Mongodb when you don't know exactly what you're schema will be. It makes it really easy, almost too easy. Now that's a double-edged sword. I've seen people create major problems for themselves by having variously data-shaped records in their db as they're figuring out their data models but I've seen the same exact thing in Postgres as well (bad schema design). Whatever you choose, good luck though!