RDS Backups & Snapshots

Continuous and Point-in-Time Recovery: Backups are continuous, enabling point-in-time recovery within the retention period.
Maintenance Window: Backups typically occur during predefined maintenance windows.
Retention Period: Users can set the retention period between 0 to 35 days. Setting the retention period to 0 disables backups.
Deletion and Retention: Upon deleting a database instance, users have the option to retain all automated backups.

IO Operations Impact: Taking snapshots can momentarily stop database operations (seconds to minutes).
Multi-AZ Consideration: For Multi-AZ deployments, snapshots are taken on the standby database, not the master.
Incremental after Initial: The first snapshot is a full capture; subsequent snapshots are incremental.
Sharing and Copying: Manual snapshots can be shared across accounts and do not expire. They can also be copied for sharing or backup purposes.
Restoration: Restoring from either a backup or snapshot results in the creation of a new database instance; in-place restores are not supported.

Manual vs. Automated: Only manual snapshots can be shared directly. Automated snapshots (backups) must be copied first.
Encrypted Snapshots: Sharing encrypted snapshots requires sharing the associated customer master key (CMK). Recipients need permissions to access the CMK to use the snapshot.
EBS Parallel: The process mirrors EBS snapshot sharing, emphasizing the need for appropriate permissions to access encrypted snapshots.

Automatic Backup Settings: By default, backups are enabled with a 7-day retention. Backup settings include the option to replicate across regions.
Snapshot Management: Users can manually create snapshots, which are retained indefinitely, contrasting with automated snapshots that have a finite lifespan.
Sharing Mechanism: Snapshots can be copied and shared with other accounts, facilitating collaborative work or cross-account data management.