Columnar data stores are not like CSV, at all. Check http://database.guide/what-is-a-column-store-database/ http://database.guide/what-is-a-column-store-databas

Columnar data stores are not like CSV, at all. Check http://database.guide/what-is-a-column-store-database/ http://database.guide/what-is-a-column-store-database/ for example "Each row can contain a different number of columns to the other rows. And the columns don’t have to match the columns in the other rows (i.e. they can have different column names, data types, etc)" This nonsense of columnar stores being a fixed schema is repeated in the next step. Graph databases misses AgensGraph which is arguably one of the most exciting database developments nowadays. Seriously, all you have to say about Aerospike is "cool name"? And MongoDB "not a database" is a very tired joke.