Unless the keys are completely random, compressed keys shorten the tree height and cause fewer pointer jumps. Hostnames are highly compressible. Plus the root a

Unless the keys are completely random, compressed keys shorten the tree height and cause fewer pointer jumps. Hostnames are highly compressible. Plus the root and the upper levels of the tree are always hot, most likely in L1/L2/L3 all the times. OTOH collisions in hash table cause pointer chase as well.