Final answer:
The ETL feature that enables the creation of multiple data streams from a single stream is referred to as data branching or branching. This feature is critical during the transformation phase and is complemented by most ETL tools to enhance flexibility and performance in data processing.
Step-by-step explanation:
The feature in ETL (Extract, Transform, Load) that allows you to create multiple streams from a single stream is known as data branching or branching. This is a part of the transformation phase where the ETL process can split a single input data stream into multiple outputs, often to perform different transformations on each branch or to meet various business logic requirements. Branching can be useful, for example, when data needs to be routed to different tables or files based on certain criteria or when parallel processing is desired to improve performance.
The implementation of branching might vary depending on the ETL tool being used. However, most modern ETL tools provide a graphical interface where branching can be designed and implemented as part of the data flow. The ability to branch out data streams efficiently contributes to the flexibility and power of ETL processes in data warehousing and business intelligence applications.