DOP-C02 practice question: DR strategies, AWS Backup and RTO/RPO (3 of 3)

Resilient Cloud Solutions A free question from our original DOP-C02 practice exam. Try it, then open the answer to see why each option is right or wrong.

An airline's loyalty program stores member points in a DynamoDB table with point-in-time recovery turned on. A faulty release last night wrote incorrect point totals to about 40,000 members between 2:00 and 2:20 a.m.

The operations team needs to recover the table to the state it had at 1:55 a.m. without restoring the whole table over the live one, so that the team can compare and repair the affected items.

The team wants the fastest recovery that does not require exporting or re-importing data by hand.

Which approach meets these requirements?

Choose one answer.

A. Restore the most recent nightly export from Amazon S3 into a new table, then copy the affected items back into the live table with a script that the team writes for the repair.
B. Restore the table to a new table at the timestamp 1:55 a.m. using point-in-time recovery, and compare the restored table with the live table to repair the affected items.
C. Create an on-demand backup of the live table now, and restore that backup over the live table, so that the members' data is returned to the state the backup captured.
D. Replay the DynamoDB Streams records from 1:55 a.m. onward into the live table with a Lambda function, reversing each change that the faulty release made.

Show the answer and explanation

Answer: B

A. Wrong: Nightly exports are from before the faulty release, so this does not reach the state at 1:55 a.m. unless an export ran at that time. Import and copy steps add manual work the team wanted to avoid. Learn more: DynamoDB data import from Amazon S3: how it works (opens in a new tab)
B. Right: Correct. Point-in-time recovery restores the table to a chosen second within the retention window as a new table, which leaves the live table untouched for comparison. The team can then repair the affected items. Learn more: Point-in-time backups for DynamoDB (opens in a new tab)
C. Wrong: An on-demand backup taken now contains the faulty totals, not the state at 1:55 a.m. Restoring it would also reproduce the bad data. Learn more: Point-in-time backups for DynamoDB (opens in a new tab)
D. Wrong: Streams records can show the changes, but reversing them with custom code is slow and error-prone at this scale. The approach also does not produce a restorable copy to compare with. Learn more: Change data capture for DynamoDB Streams (opens in a new tab)

Explanation

DynamoDB point-in-time recovery restores a table to a chosen time within the retention window, creating a new table that leaves the live table in place. The team can compare the two and repair the affected items. Exports, fresh backups and stream replay either predate the fault or require custom reversal code.

DOP-C02 practice question: DR strategies, AWS Backup and RTO/RPO (3 of 3)

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