Production databases are required to run 24×7, and therefore dominate the overall infrastructure spend.
AWS offers reservation of production database capacity for a period of 1 year or 3 years, with an option to make the full payment upfront to get a maximum discount, or to pay partially or no upfront and get a reduced hourly cost.
The AWS database reservation provides flexibility to change the instance size within the same region, e.g. your cloud database reservation of one db.m4.2xlarge instance will be valid even if you decide to use 2 db.m4.xlarge instances instead. This flexibility is not offered to Microsoft SQL Server and the License Included (LI) edition of Oracle.
References
- Amazon RDS Reserved Instances | Cloud Relational Database | Amazon Web Services. (n.d.). Amazon Web Services, Inc. https://aws.amazon.com/rds/reserved-instances/