Before any planned outage on the target database or hot , we need to create blackout for that target, to avoid incident alerts. Blackouts allow Enterprise Manager Administrators to suspend all data collection activity. ORACLE DATABASE – > MONITORING – > BLACKOUTS Select the databases or services  which want to include in blackout. You can select whether we need to initiate the blackout immediately or schedule it for future. Once target maintenance is done, we need to remove the targets from Blackout, to enable the incident and notification services.

ENTERPRISE – > MONITORING – > BLACKOUTS