As enterprise began to move to the cloud, the question of running very large Oracle databases on AWS is coming up. Of course, the definition of a what is a VLDB varies by industry, size of company, and personal opinion. For our discussion, let's say it is a 10's of TB database. In this case, most Oracle databases of this size will be running on Oracle RAC. Currently, Oracle RAC is not supported on AWS.
A method to get around the lack of support for RAC in AWS is running the application on EC2, and Oracle RAC in a co-location facility or customer data center. AWS Direct Connect allows establishing private connectivity between AWS and data center/co location or customer data center to achieve the speed required. Datapipe is one AWS hosting provider partner that has done this: