Research On Continuous Skyline Query In Spatial Database

With the popularization of personal positioning equipment and the development of global positioning system,the location-based services are gaining more attention.The traditional spatial Skyline query pay more attention to the static query,however,the inquirers are often mobile in real life.If the query algorithm is called at every moment,it will cause repeated traversal of the data set and increase computational overhead.Based on the above reasons,this paper studies the problem of continuous Skyline query in spatial database,and the main research contents are as follows:Skyline query didn't focus on the existing road network space inquirers privacy protection,inquirers his position in the process of sent to the server,it is easy to be the attacker,causing leakage location,in order to solve the query location privacy protection problems in road network space,road network is studied based on privacy protection in the space of continuous Skyline query.First of all,aiming at privacy protection in road network space,this paper constructed anonymous query area based on road network Voronoi diagram.This method can effectively protect the location of the inquirers based on road network privacy protection model.Then,this paper constructed continuous Skyline query algorithm based on anonymous query area,which can be divided into two steps:Filter data sets and build security zones.In the stage of filtering data set,this paper proposed the pruning theorem to filter data points and obtain the initial Skyline set based on Voronoi diagram of road network.In the construction of security zone phase,the pruning theorem is proposed to avoid the construction of security zone for global data points,and when the query points move,the security zone of effective data points is constructed in an incremental way.When dealing with continuous Skyline queries,the security zone effectively avoids a lot of double calculations and I/O costs.Experimental results show that the proposed method has advantages in the continuous Skyline query based on privacy protection in road network space.In order to solve the problem of continuous range Skyline query in obstacle space,an event-based incremental processing algorithm is proposed in this paper.The algorithm firstly cut the data set according to the static Skyline point,then constructed the distance intersection model according to the characteristics of query point movement in the obstacle space,and finally updated the result set according to the distance intersection time between query point and other data points.The pruning strategy proposed in this paper reduces the number of events and improves query efficiency effectively.