Databricks Data Engineer Professional Question 11
Select 3A data engineering team is designing a Delta Lake table to store critical financial transaction data in a cloud object store. The team needs to ensure atomicity and durability to prevent data corruption or loss in case of failures during updates. How does Delta Lake guarantee these properties?
- A
Delta Lake uses a transaction log to record all changes to the table, allowing atomic commits or rollbacks in case of failures.
- B
Delta Lake maintains a redundant in-memory copy of the data to guarantee durability in case of storage failures.
- C
Delta Lake stores transaction log files in cloud object storage, ensuring durability through the storage system's guarantees like replication.
- D
Delta Lake leverages the ACID compliance of cloud object storage to handle atomicity without requiring its own transaction management.
- E
Delta Lake appends all changes to the table as a new version in the transaction log, ensuring data consistency even in the event of process failures.
Show answer and explanation
Correct answers: A, C, E
Explanation
Delta Lake ensures atomicity and durability by leveraging its transaction log and the durability guarantees of cloud object storage. The transaction log records all changes to the Delta table, enabling atomic commits or rollbacks. Additionally, the transaction log is stored in cloud object storage, which provides durability through replication and fault tolerance mechanisms. Finally, Delta Lake appends changes as new table versions in the transaction log, ensuring the data remains consistent even during failures.
- A. Correct.
Correct: Delta Lake uses a transaction log to track all changes, which ensures atomic commits or rollbacks in case of failure, thereby maintaining atomicity.
- B. Incorrect.
Incorrect: Delta Lake does not maintain an in-memory copy of data for durability. Instead, durability is achieved through the use of the cloud object store and the transaction log.
- C. Correct.
Correct: The transaction log is stored in cloud object storage, which provides durability guarantees like replication and fault tolerance.
- D. Incorrect.
Incorrect: Cloud object storage alone is not ACID-compliant. Delta Lake provides its own transaction management to ensure atomicity and other ACID properties.
- E. Correct.
Correct: Delta Lake uses a transaction log to append new versions of the table. This ensures consistency and allows recovery in case of failures.