Question: EventListeners and last processed events.

[phillipbaird]

In the Courses example I noticed the read model tracks the last processed event in the course table. Each of the sql statements for the event handlers check event_id < $2 so that events are not reapplied.

My understanding is the last event processed by an event listener is stored in the event_listener table. The event listener uses this value to prevent reprocessing an event that has already been successfully handled.

Is my understanding correct?

If so, why is the event_id also being stored in the read model on the course table in the Courses example? Is this overkill or is there a reason for it that I'm not understanding?

Thanks.