PYI: Theory and implementation of database systems.

本项目的长期目标是提高性能 数据库系统的功能，特别强调 并行数据库系统 目前正在讨论的三个具体问题 解决的是在辅助设备上的数据的聚类/去聚类 存储、查询代价估计和查询中概率方法 评估和透明的检查点技术 持久的编程环境。 该研究包括 理论研究，以了解关键问题 参与，其次是分析研究，比较和对比 这些关键问题的替代解决方案， 最有前途的解决方案的原型实现。

The long-term goal of this project is to increase the performance and functionality of database systems, with a special emphasis on parallel database systems. Three specific topics currently being addressed are clustering/declustering of data on secondary storage, probabilistic methods in query cost estimation and query evaluation, and transparent checkpointing techniques in parallel persistent programming environments. The research consists of theoretical studies to gain an understanding of the key problems involved, followed by analytic studies to compare and contrast alternative solutions to these key problems, followed by prototype implementations of the most promising solutions.