1. A method for determining whether a search object matches an entry in a knowledge base, wherein the knowledge base comprises a decision tree structure comprising a plurality of search nodes, and a plurality of links joining two search nodes, said method comprising: storing a first portion of the decision tree structure in a first memory, wherein the first portion comprises a first plurality of search nodes and interconnecting links; storing a second portion of the decision tree structure in a second memory, wherein the second portion comprises a second plurality of search nodes and interconnecting links; reading a first search node from the first memory; comparing the first search node with at least a portion of the search object; and based on the comparing step, traversing a search path from the first search node to a second search node via the joining link.