AWS re:Invent 2025 - Cut costs & operate efficiently on Amazon RDS for SQL Server & Oracle (DAT325)

Optimizing Costs and Efficiency on Amazon RDS for SQL Server and Oracle

Introduction to Amazon RDS

• Amazon RDS offers managed services for running relational databases, including:
  • Amazon Aurora (PostgreSQL and MySQL compatible)
  • Open-source databases like PostgreSQL, MySQL, and MariaDB
  • Commercial databases like Oracle, SQL Server, and DB2
• Key benefits of RDS for commercial databases:
  • Ease of migration - run the same database engine on AWS
  • Flexible licensing options - bring your own license or use license-included
  • Fully managed service - automated software updates, backups, high availability

Improving Storage Flexibility

• RDS previously limited database storage to 64TB, which was insufficient for some large databases
• New features allow adding and removing additional storage volumes:
  • Up to 3 additional volumes can be added, for a total of 256TB of storage
  • Volumes can be added or removed without downtime
  • Ability to use a mix of high-performance IO2 and cost-effective GP3 volumes
• Benefits of additional volumes:
  • Accommodate large or growing databases
  • Temporary storage for short-term needs (e.g. data processing jobs)
  • Separate high-performance and infrequently accessed data
  • Improved replication throughput in multi-AZ configurations

Reducing Costs with SQL Server and Oracle Features

SQL Server Developer Edition

• SQL Server Developer Edition is now fully supported on RDS
• Developer Edition has all the features of Enterprise Edition but is free for non-production use
• Customers can use Developer Edition for dev/test environments and only pay for Enterprise Edition in production

SQL Server Web Edition with High Availability

• SQL Server Web Edition has lower licensing costs than Standard or Enterprise
• RDS now supports high availability for SQL Server Web Edition using synchronous block-level replication
• Allows running web applications on lower-cost Web Edition while still providing failover capabilities

VCPU-Based Licensing Optimizations

• RDS can now optimize CPU settings to reduce vCPU counts and lower licensing costs
• Turning off Simultaneous Multithreading (SMT) can halve the vCPU count without impacting performance
• Newer generation instances (e.g. R7 vs R6) can provide up to 55% cost savings

Oracle on EC2 Bare Metal Instances

• RDS supports running Oracle on dedicated EC2 Bare Metal instances
• Bare Metal instances bypass the hypervisor, providing better performance
• Switching from a large virtual machine to a Bare Metal instance can reduce costs by 25%

Key Takeaways

• RDS provides flexible storage options to accommodate large databases and optimize costs
• Leveraging SQL Server Developer and Web Editions can significantly reduce licensing expenses
• CPU optimization features like disabling SMT and upgrading to newer instance types can lower costs
• Running Oracle on Bare Metal instances can improve performance and reduce costs compared to virtual machines