How does RDS Custom for Oracle and Microsoft SQL Server benefit organizations?

RDS Custom for Oracle and Microsoft SQL Server provides significant benefits to organizations, primarily through the option of utilizing existing licenses in conjunction with AWS-managed infrastructure. This licensing model is known as License Mobility. Organizations that have already invested in Oracle or Microsoft SQL Server licenses can continue to use those licenses while taking advantage of the managed services offered by AWS. This reduces costs associated with licensing and enables businesses to leverage their current investments while migrating to cloud solutions.

Furthermore, RDS Custom offers flexibility that is often necessary for legacy applications or specialized configurations that are not supported by standard RDS offerings, allowing companies to maintain control over their database environment while still benefiting from AWS's management features. This option is particularly appealing for organizations seeking to optimize their cloud expenditures without sacrificing performance or functionality.

The other options do not accurately reflect the capabilities or the primary benefits of RDS Custom for Oracle and SQL Server. For instance, the service does not remove the need for proper network security, it does not provide automatic migrations, nor does it guarantee unlimited database scalability, which requires careful planning and execution based on architectural designs and resource allocation.