CDC Transformations, introduced in CockroachDB, are SQL-like statements that simplify the process of filtering, transforming, and choosing the schema for data streaming, eliminating the need for sidecar services or downstream tools. These transformations enhance the functionality of changefeeds, which stream continuous updates or snapshots from tables to external systems, by allowing users to specify only the data changes they care about, such as specific inserts, updates, or region-specific data, and by reducing data streaming costs through filtering unnecessary data. They also ensure a stable message schema even amidst schema changes and can be used for load balancing across feeds. Currently in preview, CDC Transformations are set to evolve with future releases to remove existing limitations, offering a cost-effective and efficient tool for managing real-time data pipelines for various business needs.