AWS RDS Custom: Enhanced Control for Oracle & SQL Server
What is RDS Custom?
AWS RDS Custom is a special version of Amazon RDS that allows full administrative access to the operating system (OS) and database. Unlike standard RDS, where AWS fully manages the database environment, RDS Custom provides more flexibility, making it suitable for highly customized database workloads.
✅ Supported Database Engines:
- Oracle
- Microsoft SQL Server
Key Benefits of RDS Custom
- Full OS & Database Access
- Unlike regular RDS, you can SSH into the underlying EC2 instance and modify OS settings.
- Customization
- Install custom patches, change database settings, and enable native features.
- AWS Automation & Scaling
- Still retains some RDS automation features like setup, monitoring, and backups.
How RDS Custom Works
- AWS deploys the database on an EC2 instance.
- Users gain direct OS-level access via SSH or SSM Session Manager.
- Customization is possible, but automation should be disabled temporarily to prevent conflicts.
- Taking snapshots before making changes is recommended, as mistakes could break the instance.
RDS vs. RDS Custom: Key Differences
| Feature |
RDS |
RDS Custom |
| OS & DB Access |
❌ No |
✅ Yes |
| Customization |
❌ Limited |
✅ Full control |
| Automated Management |
✅ Fully managed |
✅ Partially managed |
| Supported Databases |
Multiple (MySQL, PostgreSQL, MariaDB, Aurora, etc.) |
Only Oracle & SQL Server |
| Patching & Maintenance |
✅ AWS-managed |
✅ Manual control possible |
| SSH/SSM Access |
❌ No |
✅ Yes |
| Risk of Misconfiguration |
❌ Low |
⚠️ High (requires expertise) |