CDC: captures inserts, updates, and deletes as they happen and emits them as a change stream, enabling replication, caches, and event-driven integrations.
2 / 5
Which database mechanism does log-based CDC read from?
Log-based CDC: tails the WAL/binlog to capture committed changes with low overhead and ordering guarantees, far more efficient than polling for modified rows.
3 / 5
Why is log-based CDC preferred over query-based polling?
vs polling: polling a updated_at column misses hard deletes and adds query load; reading the log captures every change in order with minimal impact.
4 / 5
Which popular open-source tool implements log-based CDC?
Debezium: a widely used CDC platform that streams changes from databases like PostgreSQL and MySQL into Kafka, powering the outbox pattern and data pipelines.
5 / 5
What delivery guarantee does CDC typically provide to consumers?
At-least-once: on restart a CDC connector may re-emit recent changes, so downstream consumers must handle duplicates idempotently to stay correct.