Amazon DynamoDB is a fully managed NoSQL database service that provides fast and predictable
performance with seamless scalability. Push button scaling means that you can scale the DB
at any time without incurring downtime. DynamoDB is schema-less
All other options are SQL type of databases and therefore have a schema. They also rely on
EC2 instances so cannot be scaled dynamically without incurring downtime (you have to change
instance types)