MultiMap vs MultiValue Map

Question

At one place i have to use a map with many values mapped to a single key, so i was wondering whether there is any significant performance distinction between using H

Answer 1

Hash provides O(1) which is fast and does nothing with the size of elements.

Regarding to Multimap, you could put values in dependent collection (List, Set). Different collection implementations provides different performance.

EDIT: As I commented on Sebastian's answer. You could use Guava which provides different value collection implemantions: HashMultiMap (HashMap>), ArrayListMultiMap (HashMap>)...