What is the difference between RDS automated backups and manual snapshots?
Automated backups are taken daily with transaction logs, support point-in-time restore within a retention period of up to 35 days, and are removed with the instance. Manual snapshots are taken on demand and stay until you delete them.
Explain it simply
Automated backups are like an exam-time CCTV that records continuously and keeps the last few weeks, so you can rewind to 10:42 am on a given day. A manual snapshot is a photo you took and stored in an album. It stays until you throw it away.
Example
Automated backups
Schedule : daily snapshot in a backup window + transaction logs
Retention : 1 to 35 days (0 turns them off)
Restore : to any second inside the window (point-in-time recovery)
On delete : removed with the DB instance (unless you keep them
as retained backups when deleting)
Manual snapshot
Trigger : you, or a script
Retention : until you delete it
Restore : to that exact moment only
Cross-Region/account: can be copied and sharedRestoring always creates a new DB instance with a new endpoint; it does not roll back the existing one. You then point the application to the new endpoint.
Before deleting a database or making a risky change, take a manual snapshot, because it outlives the instance. RDS can offer a final snapshot when you delete an instance.
What to say in the interview
"Automated backups give point-in-time recovery inside a 1 to 35 day window and go away with the instance. Manual snapshots are kept until deleted and are what I take before risky changes. A restore always creates a new instance."
Common mistakes
- Expecting automated backups to remain after deleting the database.