Databricks Data Engineer Professional Question 12
Select 2A data engineering team is using Delta Lake to process critical financial transactions. They want to ensure atomicity and durability in their data pipeline. How does Delta Lake's transaction log and its integration with cloud object storage guarantee these properties?
- A
The transaction log records all actions as atomic commits, ensuring that either all changes are applied or none are applied.
- B
The transaction log is stored in memory to ensure faster access and durability of the changes.
- C
Delta Lake writes changes to cloud object storage before committing them to the transaction log, guaranteeing durability.
- D
Delta Lake's transaction log maintains a history of all committed transactions, enabling recovery in case of a failure.
- E
Cloud object storage automatically performs transactions on behalf of Delta Lake to maintain atomicity.
Show answer and explanation
Correct answers: A, D
Explanation
Delta Lake guarantees atomicity and durability using its transaction log, which records all changes as atomic commits and stores them in cloud object storage. This ensures that transactions are either fully applied or not applied at all (atomicity) and that changes are reliably persisted (durability). The transaction log also maintains a history of all previous transactions, enabling recovery in case of failures.
- A. Correct.
Correct: The transaction log in Delta Lake ensures atomicity by recording all changes in atomic commits. This guarantees that a transaction is either fully applied or not applied at all.
- B. Incorrect.
Incorrect: The transaction log is not stored in memory; instead, it is stored as files in cloud object storage to ensure durability and consistency.
- C. Incorrect.
Incorrect: Delta Lake writes changes to the transaction log first, which is stored in cloud object storage. This order ensures durability by persisting changes reliably before they are applied.
- D. Correct.
Correct: The transaction log maintains a complete history of all committed transactions. This ensures durability and allows recovery in case of failures.
- E. Incorrect.
Incorrect: Cloud object storage itself does not handle transactions for Delta Lake. Instead, Delta Lake uses the transaction log to manage atomicity and durability.