AWS Database Migration Service (AWS DMS) is a managed migration and replication service that helps move your database and analytics workloads to AWS quickly, securely, and with minimal downtime and zero data loss.
For terraform specific infoo, see https://sites.google.com/site/pawneecity/terraform/dms-terraform
https://medium.com/@mitchplanck/aws-dms-oracle-to-s3-9384a5d924b