Data Engineering Associate with Databricks Practice Exam

What command should you use to refresh the cache on a table?

1. UPDATE TABLE name

2. REFRESH DATA name

3. FLUSH TABLE name

4. REFRESH TABLE name

The correct answer is: REFRESH TABLE name

The command to refresh the cache on a table is "REFRESH TABLE name." This command is specifically designed to remove the cached metadata and data for a table from memory, ensuring that any subsequent queries retrieve the most current data from the source instead of potentially outdated cached information. In the context of working with big data platforms like Databricks, table caching can significantly improve performance by storing frequently accessed data in memory. However, when the underlying data changes—due to updates, deletions, or insertions—it's crucial to refresh the cache to ensure that queries operate on the most up-to-date dataset. The "REFRESH TABLE" command effectively addresses this need. Other commands presented do not serve the same purpose or exist in a practical sense within the context of table caching in Databricks. For instance, "UPDATE TABLE name" would be used for modifying existing records in a table rather than dealing with cache management. "REFRESH DATA name" is not a standard command in Databricks, and "FLUSH TABLE name" is also not recognized as it relates to table or data manipulation. Therefore, "REFRESH TABLE name" is the correct choice for ensuring that cached data reflects the latest information available in the underlying data source.