Data Engineering Associate with Databricks Practice Exam

What is the primary distinction between managed and external tables?

1. Managed tables require a schema; external tables do not.

2. Managed tables are deleted when dropped; external tables persist in their location.

3. Managed tables can be migrated easily; external tables cannot.

4. Managed tables can only be queried; external tables allow writing.

The correct answer is: Managed tables are deleted when dropped; external tables persist in their location.

The primary distinction between managed and external tables lies in how their data is handled when the tables are dropped. With managed tables, the underlying data is owned by the data warehouse system, which means that when a managed table is dropped, both the table and its associated data are permanently removed. This encapsulation allows the system to manage the lifecycle of the table and its data together, simplifying data management for users who want everything bundled. Conversely, external tables are designed to reference data that resides outside of the table's control. When an external table is dropped, only the table metadata is removed; the data remains intact in its original storage location. This characteristic allows external tables to facilitate sharing and analysis of data that might be used across multiple applications or analysis tools without fear of losing the data itself. This distinction is essential for data engineers and analysts to understand, as it influences data management strategies, lifecycle considerations, and the potential need for data persistence across different systems and use cases.