Databricks Data Engineer Professional Question 9
Select 3How does Delta Lake use the transaction log and cloud object storage to guarantee atomicity and durability when performing write operations?
- A
Delta Lake maintains a transaction log that records all changes in a serializable manner, ensuring that partial writes are never committed.
- B
Delta Lake leverages cloud object storage to store data redundantly across multiple availability zones, ensuring durability.
- C
Delta Lake requires manual checkpoints to guarantee atomicity for large transactions.
- D
The transaction log in Delta Lake enables time travel by storing all historical data versions, which also strengthens durability guarantees.
- E
Delta Lake uses a two-phase commit protocol to ensure atomicity for distributed write operations.
Show answer and explanation
Correct answers: A, B, E
Explanation
Delta Lake guarantees atomicity and durability during write operations through the transaction log and cloud object storage. The transaction log serializes all changes to ensure consistency, while cloud object storage provides durability by replicating data across zones. Additionally, Delta Lake employs a two-phase commit protocol for distributed operations to ensure that transactions are either fully committed or rolled back, preventing partial writes or data corruption.
- A. Correct.
Correct. Delta Lake's transaction log ensures atomicity by serializing all changes and preventing partial writes from being committed, which is crucial for consistency during write operations.
- B. Correct.
Correct. Cloud object storage provides durability by replicating data across multiple availability zones, ensuring data is not lost even in case of failures.
- C. Incorrect.
Incorrect. Delta Lake does not require manual checkpoints for atomicity. Checkpoints are used for performance optimizations and not for guaranteeing atomicity.
- D. Incorrect.
Incorrect. While time travel is a feature of Delta Lake, it is not directly related to guaranteeing atomicity or durability during write operations.
- E. Correct.
Correct. Delta Lake uses a two-phase commit protocol to ensure atomicity in distributed systems, allowing all or none of the write operations to be committed.