There have been a ton of start-ups that I've talked to / been a part of who used MongoDb thinking their company is going to exponentially explode in MAU and they think they'll save themselves the scaling troubles by using NoSQL. What ends up happening is the codebase gets too gnarly when they try to start doing complex analysis. SQL is appropriate for like 95% of companies. A lot of these places I'm referencing end up porting their codebase to Postgres, mysql or oracle.
Complex analytics should probably be done in a db separate from the production db anyway. The analytical db could be an RDBMS, a datacube or something else.
Absolutely agree that if you're going to be manipulating the data w/ heavy complex analysis as well as a ton of data-points, it should occur not on the prod db.
I was referring to queries such as: User needs to get a list of pharmacies they've gone to in the past 2 months that carries x-medication. Not overly complex, but annoyingly more code that would have to be written + architected in NoSQL vs a relational db.
