Amazon RDS reserved DB instances
Similar to Amazon EC2 Reserved Instances, there are three payment options for Amazon RDS reserved DB instances: No Upfront, Partial Upfront, and All Upfront. All reserved DB instance types are available for Aurora, MySQL, MariaDB, PostgreSQL, Oracle, and SQL Server database engines.
Size-flexible reserved DB instances are available for Amazon Aurora, MariaDB, MySQL, PostgreSQL, and the “Bring Your Own License” (BYOL) edition of the Oracle database engine.
For more information about Amazon RDS reserved DB instances, see the following: