The success of the World Wide Web is boosting the development of multimedia database systems and their integration into the internet. For the documents stored and exchanged in the Web there are many multimedia data formats di ering in aspects such as resolution, sampling rate, and compression. Furthermore there is a large variety of Web browsers, the data formats they support, and their network access. Thus storage servers have to store and proxy servers have to transfer many di erent formats. However, the data formats are not independent from each other but interrelated by conversion tools. There is a large number of alternatives for storage and proxy servers to store some formats or to transfer them via the network and to compute the remaining ones by applying conversion tools. To determine an optimal choice is a nontrivial optimization problem and is subject to changes of the parameters such as query pro le, available disk storage, and network bandwidth. We examine the outlined opt...
Gerhard Köstler, Wolfgang L. J. Kowarschick,