AWS Certified Solution Architect – Points to remember (RDS)
Relational Database Service.
Supported databases (AMMMOP – If it helps!)
Contrary to DynamoDB, for RDS you can select the availability Zone for RDS in a region.
There is no easy way to encrypt an all already existing unencrypted RDS instance.
You will have to make a snapshot add and encryption key to snapshot and restore the session using this encrypted snapshot.
All database backups are automatically deleted once you delete the RDS instance.
Default backup retention period is 1 day and can be extended up to 35 days.
Read replicas are Asynchronous and Multi-AZ is Synchronous.
Anything with read performance improvement points to Read Replicas and Anything with availability points to Multi-AZ Deployments.
Backups are automatically deleted if you delete the RDS instance. May be there is still a snapshot if the person who deleted selected this option.