Changxiu Cheng

Learn More
Finding a balance between data redundancy and manipulation efficiency can sometimes be problematic when building multi-scale spatial databases (MSDBs). In order to render MSDBs real-timely, coarser representations with fewer vertices should be invoked once the response time exceeds the tolerable limitation. Of course, this would result in faster response(More)
Current database with numerous users requires access control. It is also needed in spatial database systems that keep both spatial attribute and non-spatial attribute safe. The query rewriting technology in spatial database is discussed in this paper. First the operations for merging authorization policies are discussed. By classifying the subjects and(More)
  • 1