An analytical model is given for predicting the performance of a new support strategy for database views. This strategy, called the virtual method, is compared with traditional methods for supporting views. The analytical model's predictions of improved performance by the virtual method are then validated by comparing these results with those achieved in an experimental implementation.>

A methodology is presented for evaluating the performance of database update schemes in a distributive environment. The methodology makes use of the history of how data are used in the database. Parameters such as update-to-retrieval ratio and average file size can be set based on the actual characterization of a system. The analysis is specifically directed toward the support of derived data within the relational model. Because concurrency is a major problem in a distributive system, the support of derived data is analyzed with respect to three distributive concurrency control techniques: master/slave, distributed, and synchronized.>