A Survey of Query Processing Techniques over Uncertain Mobile Objects

The uncertainty of mobile objects is inherent due to the inaccuracy of data acquisition equipments,delayed update of mobile objects,privacy protection and so on.As a result of extending the traditional database with probability dimension,the ways to describe the objects,define the queries,process the queries and present the answer results have changed.And the traditional querying methods over precise data are inapplicable for the queries over uncertain data.Therefore,the query processing techniques over uncertain mobile objects have attracted more and more attention,and become one of the hot topics in the field of database.This paper discusses the challenges of the query processing over uncertain mobile objects,and summarizes the existing work on the range query,nearest neighbor query,reverse nearest neighbor query and trajectory query over uncertain mobile objects.Finally,this paper explores the research focus and the trend of this area.