1. A method of optimization for a search, the method comprising: receiving a first decision tree comprising a plurality of nodes, each node for comparing a feature value to a threshold value; determining the frequency of a first feature within the first decision tree; determining the frequency of a second feature within the first decision tree; ordering the features based on the determined frequencies; storing the ordering such that values of features having higher frequencies are retrieved more often than values of features having lower frequencies within the first decision tree.