Which of the following is NOT a feature of Delta Lake?

In the context of Delta Lake, real-time data encryption is not a built-in feature of the Delta Lake architecture itself. Delta Lake is primarily focused on enhancing the data storage capabilities and management of big data workloads on Apache Spark, providing functionalities such as ACID transactions, scalable metadata handling, and data versioning through features like time travel.

In contrast, Delta Lake does indeed support deletes, updates, and merges, which allows for more dynamic data manipulation compared to traditional data lakes. It also offers comprehensive audit history, enabling users to track changes and maintain a record of data modifications over time. Time travel capabilities are another key feature, allowing users to query previous versions of data, which can be incredibly useful for recovery and auditing purposes.

While security features such as data encryption can be implemented around Delta Lake through the underlying infrastructure or additional security frameworks, encryption as a feature specific to Delta Lake itself does not exist, clarifying why real-time data encryption is the option that does not align with Delta Lake's core functionalities.