Developments in network and switching technologies have made telecommu- cations systems and services far more data intensive. This can be observed in many telecommunications areas, such as network management, service mana- ment, and service provisioning. For example, in the area of network management the complexity of modern networks leads to large amounts of data on network topology, configuration, equipment settings, etc. In addition, switches generate large amounts of data on network traffic, faults, etc. In the area of service ma- gement it is the registration of customers, customer contacts, service usage (e.g. call detail records (CDRs)) that leads to large databases. For mobile services there is the additional tracking and tracing of mobile equipment. In the area of service provisioning there are the enhanced services like for example UMTS, the next generation of mobile networks, but also the deployment of data intensive services on broadband networks such as video-on-demand, high quality video conferencing, and e-commerce infrastructures. This results in very large databases growing at high rates especially in new service areas. The integration of network control, network management, and network administration also leads to a situation where database technology gets into the core of the network (e.g. in architectures like TMN, IN, and TINA).