Performance Implications and Special Considerations

The outbox pattern gives you safe event publishing. That safety has a price: delay, extra writes, disk space, and duplicates. This lesson explains each cost and shows how to keep it small.

Publish Delay

An event is not visible to consumers the moment its row commits. The relay must find the row and publish it first. That gap is the publish delay.

With a polling relay, the polling interval sets the longest wait. A typical interval is 100 milliseconds to a few seconds. On average, an event waits about half an interval before the relay sees it.