Which three are true about thresholds, metrics, and server-generated alerts? (Choose three.)
- A.All metrics are instance related.
- B.Cleared stateful alerts are displayed by querying DBA_ALERT_HISTORY.
- C.A space usage management alert is automatically cleared after the underlying problem is resolved.
- D.They are generated by SMON when a tablespace is 97% full.
- E.Metrics are statistical counts for a specific unit.
- F.STATISTICS_LEVEL must be set to ALL to generate alerts.