A pen-based database interface for mobile computers

The appearance on the market of pen-based computers with wireless communication capabilities has led to the ability to access geographically distributed information bases. Moreover, such computing devices require database interfaces that are easy-to-use, avoid large-scale data input via keyboard use, and are suited for smaller display screens. We establish the need for newer interfaces to deal with problems specific to mobile computing devices that use the pen as a primary input device. We describe an implementation of a pen-based graphical database interface on a pen computer (using the PenPoint operating system) with a built-in cellular phone. Using the cellular phone capability, the interface connects to remote databases and displays the schema information of the database chosen by the user. In response to gestures made by the user using the pen, the interface automatically generates queries and retrieves results. We use the 'universal relation' concept to aid in automatically generating queries based on the attributes chosen by the user. We provide a summary of the status of this interface, some implementation details and suggest some future directions.