What key feature does Delta Lake offer to ensure data consistency?

Delta Lake offers ACID transactions as a key feature to ensure data consistency. ACID stands for Atomicity, Consistency, Isolation, and Durability, which are fundamental principles that guarantee reliable processing of database transactions.

When utilizing Delta Lake, transactions are treated as a single unit of work that either completes fully or has no effect at all if it fails, thus preserving the consistency of the data. This means that when concurrent operations are performed, Delta Lake ensures that all reads and writes are accurately managed, preventing issues such as dirty reads, lost updates, and other anomalies that can occur in distributed data systems. By providing these robust transaction guarantees, Delta Lake is able to maintain the integrity of the data even in complex scenarios involving multiple users and processes.

Other options, while useful features of Delta Lake, do not specifically address data consistency in the same way. Schema evolution allows for flexible schema management over time, data redundancy relates more to data storage optimization strategies rather than consistency, and real-time processing pertains to the timing of data availability rather than its consistency integrity.