Abstract: The present disclosure provides a method of optimizing a search system, which relates to a field of data processing, and in particular to a field of data search. The method is implemented to include: determining a first hit rate of a cache unit of the search system for a plurality of user queries; for each element in a first set of elements, determining at least one key element by: generating a plurality of first queries that correspond to the plurality of user queries; determining a second hit rate of the offline cache unit for the plurality of first queries; and determining the element as one of at least one key element in response to determining that a difference between the second hit rate and the first hit rate is less than a difference threshold; and optimizing the search system based on the at least one key element.