Principle:Risingwavelabs Risingwave CDC Schema History
| Knowledge Sources | |
|---|---|
| Domains | CDC, Schema_Management, Recovery |
| Last Updated | 2026-02-09 07:00 GMT |
Overview
Schema history tracking and recovery mechanism for CDC connectors, enabling replay of DDL changes during connector restart.
Description
CDC Schema History manages the record of database schema changes captured during CDC replication. When a CDC connector restarts, it must reconstruct the schema state at the point where it left off. The schema history stores DDL events (CREATE TABLE, ALTER TABLE, etc.) alongside their binlog/WAL positions, enabling the connector to replay schema changes up to the desired offset. This is critical for databases like MySQL where schema changes are embedded in the binlog stream. The history can be stored in various backends (memory, file, or cloud object storage via OpenDAL) and uses position comparators to determine which history records to replay during recovery.
Usage
Apply this principle when implementing CDC connectors that need to track and recover schema state across restarts, particularly for MySQL and MariaDB sources where schema changes are interleaved with data changes in the binlog.