Following query is redundant and is performed every 10 seconds without using changelog which leads to IO every 10 seconds on installations with limited resources:

select i.itemid,i.hostid,i.templateid from items i inner join hosts h on i.hostid=h.hostid where h.status=3;

Also this query is redundant and slow down configuration sync:

select i.itemid,i.hostid,i.templateid from items i where i.flags=2

Item tables is already retrieved later with changelog, so there is no need to read this data in separate queries specially with table that can be so large.