select * from(
select t.code, sum(t.totalsum) from smdocdisccard t, smdocuments a
where t.doctype=a.doctype
and t.id=a.id
and to_date(a.createdat,'DD.MM.YY') > to_date('31.12.2005', 'DD.MM.YY')
group by t.code
order by sum(t.totalsum) desc)
where rownum<11