The query below takes about 4 min to finish. As it runs all the time the CPU load of my database server is always too high.

Query:

SELECT p.eventid,p.objectid,p.clock,p.ns FROM problem p WHERE p.source='0' AND p.object='0' AND NOT EXISTS (SELECT NULL FROM functions f,items i,hosts_groups hgg LEFT JOIN rights r ON r.id=hgg.groupid AND r.groupid='18' WHERE p.objectid=f.triggerid AND f.itemid=i.itemid AND i.hostid=hgg.hostid GROUP BY i.hostid HAVING MAX(permission)<2 OR MIN(permission) IS NULL OR MIN(permission)=0) AND (p.r_eventid IS NULL OR p.r_clock>1501009178) AND p.eventid<='4067533' ORDER BY p.eventid DESC LIMIT 1001 OFFSET 0