How Change Data Capture (CDC) Works

This post introduces Change Data Capture (CDC) as a pattern to extract data changes from relational databases into event streams. It explains the limitations of traditional databases for real-time reactions and contrasts CDC with older active database concepts like ECA rules and triggers. The post highlights the benefits of sourcing CDC events from transaction logs (e.g., using Debezium) over polling or trigger-based approaches. It also discusses the importance of denormalizing data for event streams and provides a conceptual example of how normalized order data can be transformed into a denormalized event.