The cancelled delivery becomes Discarded now, freeing its key; anything else is LeaseLost with no change (03 §5).
Releases the consumer's independent executor (03 §11).
'Held' | 'Lost' | 'Cancelled' (03 §7). A thrown error is transient: the runtime retries on its next tick.
Optionalprogress: WorkProgressOne claim cycle. The Database consumer never long-polls, so waitSeconds is ignored; the runtime's idle backoff paces it.
Database: no attempt consumed. SQS: the receive is already counted (spec 03 §5.1).
The Database transport's consumer (03 §7, §11). It owns one independent executor, never runs a statement on the shared source, and never opens a transaction: every claim, heartbeat and settle is a single guarded procedure call.