Deleting old events from the outbox, so domain_events doesn't grow forever.

DDD.Outbox.Retention.prune(MyApp.Repo, older_than_days: 30)
# => {:ok, %{deleted: 1204}}

Or from the command line: mix vic.outbox.prune --older-than-days 30. To prune on a schedule, give the supervisor retention: [older_than_days: 30] (see DDD.Supervisor) or call prune/2 from your own scheduler.

What is deleted, once it is older than the limit:

• events that were published (every handler succeeded or rejected them), together with their delivery records
• dead letters that were resolved (discarded or replayed)

What is never deleted: events still waiting, events being retried, and dead letters nobody has resolved.

Pruning is a choice with a cost. A projection's rebuild/0 replays the events in this table; once the old ones are gone, a rebuild can only rebuild from what is left. Prune after the longest history you are willing to rebuild from, or archive the table first.