To limit the number of records/results returned by the search criteria(notice we are not using DetachedCriteria):
Criteria criteria = getSession().createCriteria(MyClass.class);
criteria.setMaxResults(100);
List< MyClass > list = criteria.list();
if (list != null && list.size() > 0)
{
log.warn("Found " + list.size() + " Impressions");
}
return list;