As usual, the confusion and religious comments are numerous. There is no such thing as "nosql". There are different types of databases, with traditional relational being useful for 95% of scenarios (especially on increasingly fast servers with decent replication features) while the rest of the time something more specific is needed.<p>SQL is just an interface, obviously common to relational databases but can be applied to any datastore. Spark/Drill/Presto/Dremio/etc can give you SQL over any data, even just files in a folder somewhere, so let's clear up this notion between actual database technology and the access path.<p>Document stores are definitely useful. MongoDB is one of the better ones today although it had a rocky start. RethinkDB was an interesting experiment but never matured, RavenDB is a solid contender, Couchbase has proven itself, Riak might stick around, and there are dozens of others.<p>There is a place for everything and MongoDB is being used by plenty of companies to great extent. It might not always be the right choice but when it is, it works incredibly well. Good luck to the team, I'm glad to see the success in both the product and the company.