When you use Standard RDS, AWS controls everything. You just use the database. You cannot touch the server underneath it.
That's fine for most apps — but sometimes you need more control. Like: installing something on the server, or applying a specific patch yourself.
That's where RDS Custom comes in.
It's a middle ground between Standard RDS and doing everything yourself.
Standard RDS RDS Custom Self-managed on EC2
(AWS controls all) ←——— (shared control) ———→ (you control all)
Simple version: RDS Custom lets you use a managed database AND still get into the server when you need to.
Only available for: Oracle and Microsoft SQL Server
| Standard RDS | RDS Custom | |
|---|---|---|
| Can you access the server? | ❌ No | ✅ Yes |
| Can you customize deeply? | ❌ Limited | ✅ Full |
| Who handles patching? | AWS | You |
| Who is it for? | Most apps | Special Oracle / SQL Server needs |
Patching = installing small updates/fixes on the database or server to fix bugs or close security holes.
In Standard RDS, AWS does this automatically for you. In RDS Custom, you decide when and how to patch — useful when your app needs a specific version and you don't want AWS changing things without notice.
All of these are impossible in Standard RDS: