What should you do?

You released a popular mobile game and are using a 50 TB Cloud Spanner instance to store game data in a PITR-enabled production environment. When you analyzed the game statistics, you realized that some players are exploiting a loophole to gather more points to get on the leaderboard. Another DBA accidentally ran an emergency bugfix script that corrupted some of the data in the production environment. You need to determine the extent of the data corruption and restore the production environment.

What should you do? (Choose two.)
A . If the corruption is significant, use backup and restore, and specify a recovery timestamp.
B . If the corruption is significant, perform a stale read and specify a recovery timestamp. Write the results back.
C . If the corruption is significant, use import and export.
D . If the corruption is insignificant, use backup and restore, and specify a recovery timestamp.
E . If the corruption is insignificant, perform a stale read and specify a recovery timestamp. Write the results back.

Answer: A, E

Explanation:

https://cloud.google.com/spanner/docs/pitr#ways-to-recover

To recover the entire database, backup or export the database specifying a timestamp in the past and then restore or import it to a new database. This is typically used to recover from data corruption issues when you have to revert the entire database to a point-in-time before the corruption occurred.

This part describes significant corruption – A

To recover a portion of the database, perform a stale read specifying a query-condition and timestamp in the past, and then write the results back into the live database. This is typically used for surgical operations on a live database. For example, if you accidentally delete a particular row or incorrectly update a subset of data, you can recover it with this method.

This describes insignificant corruption case C E https://cloud.google.com/spanner/docs/pitr https://cloud.google.com/spanner/docs/backup/restore-backup