Which of the following best describes Delta Lake in Fabric?

• A. A visualization library.
• B. A relational storage layer for Spark enabling Parquet-based tables.
• C. A real-time streaming engine.
• D. A machine learning library.

Answer: (B)

Delta Lake in Fabric acts as a relational storage layer for Spark that enables Parquet-based tables. It adds reliability to data lakes by providing ACID transactions, scalable metadata handling, and schema evolution on top of Parquet files, so Spark SQL and other tools can query Delta tables with the guarantees of a relational system. The data remains stored as Parquet files, while the transaction log tracks changes, enabling consistent reads, time travel, and efficient upserts and deletes. It’s not a visualization library, a real-time streaming engine, or a machine learning library—the role here is to manage and provide reliable, query-friendly storage for Spark-based workflows.