oracle8.1.6 select notification_id from notifications where sysdate - notif_date > 2 and not exists (select notifications.notification_id from notifications, notification_requests, notification_user_map where notifications.type_id = notification_requests.type_id and notifications.object_id = notification_requests.object_id and notifications.notification_id = notification_user_map.notification_id(+) and sent_date is null) select notifications.notification_id, notif_subject, notif_text, notif_html, notification_requests.user_id, notification_requests.type_id, notification_requests.delivery_method_id, notifications.response_id from notifications, notification_requests, notification_user_map where notifications.type_id = notification_requests.type_id and interval_id = :interval_id and notifications.object_id = notification_requests.object_id and notifications.notification_id = notification_user_map.notification_id(+) and sent_date is null and notifications.notif_date <= (sysdate - (select n_seconds / 3600 / 24 from notification_intervals where interval_id= :interval_id)) order by notification_requests.user_id, notification_requests.type_id