Data Engineering Associate with Databricks Practice Exam

Which SQL command is used to change the retention duration for Delta table files during vacuuming?

1. SET spark.databricks.delta.vacuum.retentionDuration

2. SET spark.databricks.delta.retentionDurationCheck.enabled

3. SET spark.databricks.delta.vacuum.logging.enabled

4. SET spark.databricks.delta.retentionTime

The correct answer is: SET spark.databricks.delta.vacuum.retentionDuration

The command that is utilized to change the retention duration for Delta table files during vacuuming is the command that specifies the retention duration directly. This command adjusts the configuration that determines how long files in a Delta table are retained before they can be removed by the vacuum operation, thereby allowing for the accurate management of storage and data retrieval. When using Delta Lake, vacuuming is essential for managing the underlying Parquet files and ensuring that the data remains performant and optimized. The retention duration defines how long Delta maintains files that are no longer referenced by prior versions of the table. If the duration is set to a longer time, it prevents the vacuum operation from removing these files, which is particularly useful for preventing accidental loss of data that may still be needed for operations such as time travel or rollback. The other options, while relevant to different aspects of Delta Lake management, do not specifically address the retention duration of files during vacuum operations. They may pertain to enabling logging or other configuration settings but do not change the core retention duration, which is the primary focus of this question.