Database Access in Mobile Environments

Mobility is the cause for new requirements on database systems. Database systems used in classical LANor hostbased environments provide these new features deficiently. New concepts are needed in mobile environments. The conventional client-server architecture has to extended in a client-agent-server architecture. We describe new approaches in database technology to meet the new requirements like adaptive database system components and intensified use of query statistics. This includes the management of queries and query results. The access to the information will be done via an OQL-like interface. The OQL query will be transformed into queries of the underlying relational or object-oriented database systems used by the information servers. Mobile computing with the help of small devices via wireless networks is in our opinion only one possible mobile scenario. In this paper we present a new and more general interpretation of mobility based on mobility of users. The work on mobile database access in this paper is part of the project “Mobile Visualization” (MoVi). Users not only get access to heterogeneous information from different places, with different technical environments and with different aims, in a homogeneous way, but also want to visualize this data adequately.