In addition to database engines, developers can choose between first and second generation MySQL instances. The First Generation of MySQL instances was initially released in 2011, and designed with App Engine compatibility in mind. Generally speaking, second generation instances are vastly superior in feature set, performance, and cost. When creating a new MySQL instance, opt for the second generation whenever possible.
First generation instances support two activation policies: on-demand and always-on. Much like App Engine instances are capable of scaling down to zero, on-demand Cloud SQL instances are shut down during periods of inactivity. The instance will then be started upon a new connection, and will be billable while ...
