I've built an interactive demo for CDC to help explain how it works.

The app currently shows the transaction log-based and query-based CDC approaches.

Change Data Capture (CDC) is a design pattern that tracks changes (inserts, updates, deletes) in a database and makes those changes available to downstream systems in real-time or near real-time.

CDC is super useful for a variety of use cases:

- Real-time data replication between operational databases and data warehouses or lakehouses - Keeping analytics systems up to date without full batch reloads - Synchronizing data across microservices or distributed systems - Feeding event-driven architectures by turning database changes into event streams - Maintaining materialized views or derived tables with fresh data - Simplifying ETL/ELT pipelines by processing only changed records

And many more!