1. A method comprising: receiving an incremental update specifying a new rule definition including a modification of at least one field of a designated rule of a plurality of rules, the plurality of rules being represented by a Rule Compiled Data Structure (RCDS) as a decision tree for packet classification utilized by an active search process, the plurality of rules representing a search space for the packet classification, each rule of the plurality of rules having an original rule definition defining a subset of the search space; determining an intersection of the new rule definition specified and the original rule definition of the designated rule; setting the original rule definition of the designated rule to an intermediate rule definition defined by the intersection determined and incorporating a series of one or more updates determined in the RCDS, atomically from the perspective of the active search process; and setting the intermediate rule definition of the designated rule to the new rule definition and incorporating the series of one or more updates determined in the RCDS, atomically from the perspective of the active search process.