Databricks Certified Data Engineer Associate — Question 107

A data engineer has realized that they made a mistake when making a daily update to a table. They need to use Delta time travel to restore the table to a version that is 3 days old. However, when the data engineer attempts to time travel to the older version, they are unable to restore the data because the data files have been deleted.

Which of the following explains why the data files are no longer present?

Answer options

• A. The VACUUM command was run on the table
• B. The TIME TRAVEL command was run on the table
• C. The DELETE HISTORY command was run on the table
• D. The OPTIMIZE command was nun on the table

Correct answer: A

Explanation

The correct answer is A because the VACUUM command permanently removes files that are no longer needed, including those associated with older versions of the table. The other options do not lead to the deletion of data files; for instance, TIME TRAVEL is used to access previous versions without deleting them, DELETE HISTORY affects metadata, and OPTIMIZE is for performance improvements without removing historical data.