Databricks Data Engineer Associate Question 404
Single answerA company is using Databricks to manage their data warehouse and has set up a Delta table to track customer order updates. They want to ensure that their analytics dashboard always shows the most recent customer order state by processing incremental changes from a source table. Which statement best describes the behavior of the APPLY CHANGES INTO operation in this scenario?
- A
APPLY CHANGES INTO processes incremental changes and ensures that the target table reflects the latest state of the records in the source table.
- B
APPLY CHANGES INTO deletes historical records in the target table to keep only the most recent changes.
- C
APPLY CHANGES INTO appends all incremental changes from the source table into the target table without reconciling the state of the records.
- D
APPLY CHANGES INTO is used to create a new Delta table from scratch and does not support updates to an existing table.
Show answer and explanation
Correct answer: A
Explanation
The APPLY CHANGES INTO operation is used in Delta Live Tables to implement Change Data Capture (CDC). It processes incremental changes from a source table and applies them to a target Delta table, ensuring the target reflects the latest state of the source data. This makes it ideal for scenarios where the most up-to-date information is needed, such as analytics dashboards.
- A. Correct.
Correct: APPLY CHANGES INTO is specifically designed to process incremental changes and update the target Delta table to reflect the latest state of records in the source table. It reconciles changes such as inserts, updates, and deletes.
- B. Incorrect.
Incorrect: APPLY CHANGES INTO does not delete historical records unless explicitly configured to do so. By default, it maintains a full record of changes.
- C. Incorrect.
Incorrect: APPLY CHANGES INTO does not simply append changes; it aligns the target table with the source table by applying updates, inserts, and deletes based on the source data.
- D. Incorrect.
Incorrect: APPLY CHANGES INTO is not used to create a new table but rather to update and manage an existing Delta table's state.