What is change data capture (CDC)?

Answer

Change data capture is a technique that detects and streams row-level changes (inserts, updates, deletes) from a source database so downstream systems can stay in sync in near real time. The most efficient approach reads the database transaction log (such as the MySQL binlog or PostgreSQL WAL) rather than repeatedly polling tables, which avoids extra load and captures every change in order. CDC powers data replication, cache invalidation, search indexing, and feeding data lakes and streaming pipelines. Common tools include Debezium, and many managed services offer built-in CDC.