Nah. You assume branching factor of 2 (and not radix tree but

rather a

form of binary tree, i.e. AVL, r/b or Patricia - they have that

O(log2(num_entries)) behaviour, while radix trees are traversed in

O(key_length/branching_factor)).

I assumed a binary radix trie (not tree) because that's the normal

cannonical version used by computer science students. Yes, as you

outlined, there are many games you can play, if you're willing to make

space/time tradeoffs.

Regardless of the details, the point remains: if your data structures

are largely constant, then you are more efficient searching a small data

set vs. searching a large one.

Tony