Querying and Visualization of Geometric Data

This paper describes the retrieval, browsing and visualization of data for a spatial database system developed at the University of Waterloo. The prototype, called QL/G, supports geometric data types like general regions, lines and points as built-in data types. A Graphical User Interface (GUI), written in X/Motif and a persistent version of C++, is provided for users as an effective tool for querying and visualizing data retrieved. The interface is simple, userfriendly and flexible, and provides the necessary functionality identified in existing literature for geographic applications. Keywords Graphical User Interfaces, Visualization, Query Languages, GIS, Spatial Databases. 1 Introduction A spatial database management system (SDBMS) is a data base system with capabilities for the representation and manipulation of geometric data such as points, lines and regions. Geometric data are commonly used to represent shape and location of objects in the real world. This type of database te..