Hashtables are by far not the only way to associate a number of keys with respective values. They have some nice properties and some rather ugly properties (mem

Hashtables are by far not the only way to associate a number of keys with respective values. They have some nice properties and some rather ugly properties (memory usage, growing/shrinking, iteration, seeding / table poisoning). Most RDBMS (for example) tend to use trees instead for indices. And then there's the whole category of tries.