Relational databases (sans JSON columns) are limited in the same way that seatbelts limit your ability to be transfenestrated during a crash.
Having a rigid and well-designed schema is a mechanism to keep you or your team from doing stupid things.
Having a rigid and well-designed schema is a mechanism to keep you or your team from doing stupid things.
Cassandra et al. IMO only fall under the NoSQL banner by retconning the meaning to be “Not Only SQL.” Columnar DBs are a fine idea for certain uses.
Document DBs and/or chucking everything into a JSON column, though… those can die in a fire.