In this section, we present three demos of query processing in the CQA/CDB system. The data models are obtained from http://www.cse.uconn.edu/cdb, which also provides the queries that had been tested in the system. As shown in the following demos, the CQA/CDB system can handle both the traditional and spatiotemporal data by using a uniform query language, which is a critical advantage over common GIS systems.