The Berkeley group views the electronic library as a modern database application, and we are building it on top of the POSTGRES next-generation DBMS[\protect\citeauthoryearStonebraker &Kemnitz1991]. The development effort at Berkeley is being carried on in parallel with Sequoia 2000, a research project that is developing a very-large-scale multimedia object server, with a focus on managing scientific data on global climate change.
We expect that the electronic library will be a useful tool for Sequoia researchers and that documents useful to them will be made available along with the Computer Science technical Reports. We also expect that Sequoia will provide us with a variety of alternative types of data (including images, video, etc.) that will enrich the universe of data types available for our exploration and use in the electronic library. There has been much synergism between the two projects. The Sequoia project has provided a base of workstation hardware and large-scale data storage devices that are being shared to provide computing and storage resources for the electronic library project. We are also sharing some of the software that has been developed for each project. The CSTR project has modelled its overall system architecture to support the electronic library of technical reports in part on the DBMS-centric architecture developed for the Sequoia project, and in part on the current de facto standard applications for network search and retrieval of information. Figure 1 shows the overall architecture of the CSTR electronic library system in its current configuration.
This architecture can be considered as set of functional layers mediating between the user of the system and the stored data. These functional layers are the Application or User Interface layer, the Network Protocol layer, the Data Management layer, the Filesystem layer, and the Device layer. The following sections will examine each of these layers, from the Device Layer up through the User Interface Layer, for the current CSTR system.