Encountered change event for table db.table_name whose schema isn't known to this connector

Root cause

Debezium cannot decode a change event because it lacks the DDL history for that table. Causes: (1) the schema history topic was compacted or expired, (2) a new table was added to table.include.list after the initial snapshot, (3) the connector name was changed (new offset key, empty schema history).

How to fix

1. Ensure the schema history topic has retention.ms=-1 and cleanup.policy=delete (never compact).
2. For a newly added table: trigger an incremental snapshot via the Debezium signals table.
3. If schema history is corrupted: set snapshot.mode=recovery to rebuild it from the live database.
4. Check that schema.history.internal.kafka.topic is unique per connector — sharing topics causes this.