Comment by ashinybrowncoat

We use a mix of SQL and NoSQL databases for different and specific purposes. Your suggestion is to do the data manipulation outside of the database which typically means pulling data sets out, doing something with them, and then putting them back in. That will never be more efficient than just doing it in the database. Our SQL databases are actually scaled horizontally using read replicas since writes are much less frequent than reads and we can easily add/remove instances as demand grows and shrinks. IMO, it wasn't any more difficult to scale out our databases than it would have been to implement any other K8 (application or DB).