Query updates

Once CPM receives the location update from a query $q$ , $q$ and all of its related information (i.e., $q.kNN$ and the book-keeping information) is deleted and then a new continuous query is issued on the new location and computed from the scratch. Obviously, such computation does not utilize the previous computed information of $q$ .

We show that by employing CircularTrip, our $k$ NN algorithm guarantees that the minimum number of cells are accessed during computation of initial results and continuous monitoring. CircularTrip based algorithm overcomes the problems described above.