Cache replacement method based on lowest access cost for location dependent query

Abstract

Because of the user's mobility and the location dependency of data,new challenge has been brought to cache replacement strategy for Location Dependent Query(LDQ).Based on the detailed analysis of the space location characteristics of Location Dependent Data(LDD) and several typical replacement strategies of location dependent cache,the authors proposed a prioritized approach cache replacement based on the lowest access cost(PLAC),the PLAC took some important factors into account such as access probabilities,update rates,data distance,valid scope.To ensure the maximum utilization of limited cache,the PLAC cache replacement strategy decided which data would be replaced according to the value of the lowest cost function.The contrast experiments show that the PLAC increases cache hit rate and shortens query average response time more effectively than other location dependent cache replacement strategies.