Databricks Data Engineer Associate Question 285
Single answerA data engineering team accidentally updated a Delta table and now wants to roll it back to a previous version. What is the correct approach they should use?
- A
Use the RESTORE command to revert the table to a specific version.
- B
Query the Delta table's history to identify the desired version and use the RESTORE command with that version number.
- C
Use the VACUUM command to remove all data after the desired version.
- D
Identify the desired version using DESCRIBE HISTORY and use the RESTORE command to roll back to that version.
Show answer and explanation
Correct answer: D
Explanation
To roll back a Delta table to a previous version, the correct process is to first identify the desired version using the DESCRIBE HISTORY command. Once the version is known, the RESTORE command can be used to revert the table to that version. This ensures that the table's state is accurately restored without data loss or corruption.
- A. Incorrect.
The RESTORE command cannot directly revert a table without specifying the version. Additional steps are needed to identify the version first.
- B. Incorrect.
While querying the Delta table's history is a required step, the RESTORE command itself does not take a version number directly from a query. Additional syntax is needed.
- C. Incorrect.
The VACUUM command is used to clean up old data files and cannot be used to roll back a table to a previous version.
- D. Correct.
This is the correct approach. Using DESCRIBE HISTORY allows the team to identify the specific version, and the RESTORE command can then be applied to roll back to that version.