The difference between Continuous backup and PITR in DynamoDB

Question: When I look at the  dynamodb decribe-continuous-backups command , there is reference to both ContinuousBackupsStatus and PointInTimeRecoveryStatus . What is the difference and is  it possible to restore if PointInTimeRecoveryStatus  is DISABLED ?

aws dynamodb describe-continuous-backups --table-name abc2


{
    "ContinuousBackupsDescription": {
        "ContinuousBackupsStatus": "ENABLED",
        "PointInTimeRecoveryDescription": {
            "PointInTimeRecoveryStatus": "DISABLED"
        }
    }
}

Answer: It can be confusing as Continuous backups is ENABLED for all DynamoDB tables , whereas PointinTimeRecovery (PITR )needs to be explicitly ENABLED.

If PITR is not ENABLED than there is no recovery point  available.     Obviously - you may also be using AWS Backup or creating Snapshots .   But if you are not creating other backups and do not have PITR enabled than there is no recovery point . 

One side-benefit of enabling DynamoDB PITR is the ability to Recover deleted DynamoDB table with Point-In-Time Recovery Enabled

When PITR is enabled ,  the replication logs begin to be moved into  S3 .   There is also a periodical scan & snapshot of the B-tree to s3.

So when you want to restore a PITR there is a sequence of events leading to a consisten restore:

1) Looks at all the artefacts in s3 related to the DynamoDB table based on the Restore Time

2) Finds a "snapshot "in the past and all the logs associated from that point up to the required restore time 

3) Restore the snapshot and apply the logs 

Related articles on AWS DynamoDB backup & Restore

Amazon DynamoDB Backup & Restore