In the last three years, AWS/RDS has evolved, and new features may have been introduced. While the original post was from a while back, it's worth considering the current state of AWS/RDS. AWS/RDS provides various database engines, including both Oracle and Postgres. However, creating a direct DB link between Oracle and Postgres databases on AWS/RDS is not a native feature. For a more detailed and up-to-date understanding of the available options and their implementation, I recommend referring to the AWS documentation. To further expand your knowledge and expertise on AWS services, you can explore AWS training offerings. They provide valuable courses and materials that cover a wide range of AWS topics.