If the count of entities is dynamic, but can grow up to 1600000 items, you should use the HybridDictionary. It stores the name/value pairs in an very efficient way. This Dictionary uses the ListDictionary for small count of items and switches automatically to Hashtable if the count grows to a large amount of items. (Sorry, i dont know the Limit when this happens) Hope this helps
Der Staat mit der niedrigsten Geburtenrate ist nicht die Bundesrepublik, sondern der Vatikan.