Change Data Capture
Change data capture (CDC) is how HVR replicates data changes in real-time. As its name implies, CDC identifies changes and can then synchronize incremental changes with another system or store an audit trail of changes.
CDC comes in multiple flavors, including trigger based and log-based. HVR gives you the option to use both types. However, log-based CDC is superior since it can be applied to all possible scenarios including systems with extremely high transaction volumes. Our product includes log-based CDC for all supported relational database sources.
The biggest benefits of log-based CDC include:
- Minimal Impact: Log-based CDC has less impact on the database because it reads directly from the logs without directly impacting the transaction. In contrast, trigger-based CDC creates triggers on tables that require change data capture, and firing these slows down transactions.
- Fast performance: HVR directly reads the logs on the file system allowing highly efficient change data capture, supporting large volumes of data.
- More flexibility: log-based capture supports more data operations such as truncates, and enables support for DDL capture.