In addition to running databases on the cloud independently, Amazon Web Services has cloud-based database alternatives( Relational and NoSQL databases).
DynamoDB is a scalable proprietary NoSQL database offered by Amazon.com
Amazon Redshift is a cloud-based big data analytics database service offered by Amazon.com
ElastiCache is a memory cache service offered by Amazon.com. ElastiCache supports open-source in-memory Memcached and Redis.
Amazon Relational Database Service ( Amazon RDS) is a distributed relational database service offered by Amazon.com. It is a scalable relational database in the cloud.
for more information visit aws.amazon.com