Agreed, using Debezium would be great for that. Data change notifications look promising, but maybe I indeed underestimate the task.

The code living in the database would need to depend on Hibernate ORM and Hibernate Search?

Hum, no, it'd be task of the code on the receiving end to identify those entities affected by given table data changes. The task of determining these entities needs to be done with either approach.

Anyways, I'm fine with closing this issue or re-purposing it to integrate with DBZ once it's there. I'll need to take some time and look into the same in some more depth.