Support of Historical References in Database

在计算机科学和工程的几个领域中，支持历史引用是一个重要的问题。数据库社区的最新进展特别提到了数据库版本控制问题(即保留和访问旧版本)的重要性。在快速增长的面向对象编程领域中，历史引用使程序员能够基于以前的对象版本创建新对象。支持历史参考文献的传统方法要么需要很大的空间，要么需要很长的重建时间，这使得这种参考文献的广泛使用变得令人望而却步。该项目提供了对历史引用的有效支持，即在不牺牲大量存储空间的情况下快速重建到任何过去的状态。研究了压缩时间数据的新的最佳方法，同时仍然提供对这些数据的任何过去参考的实际随机访问。此外，还分析了分布历史、保存像图一样演化的系统的历史、将历史保存在有限空间中以及其他一般历史查询(不按时间索引而是使用历史相关性)的问题。这个项目的结果将极大地影响不同程序员或数据库用户使用已记录的过去历史。要考虑的这些结果的其他应用，包括网络管理工具、动画存储和归档Unix目录系统。

Supporting historical references is an important problem in several areas of computer science and engineering. The significance of the database versioning problem (i.e., keeping and accessing old versions) has been particularly mentioned in recent advances in the database community. In the rapidly growing area of object oriented programming, historical references enable programmers to create new objects based on previous object versions. Traditional approaches to supporting historical references require either large space or long reconstruction times, making the extensive use of such references prohibitive. This project provides efficient support of historical references, i.e., fast reconstruction to any past state without sacrificing a large amount of storage space. New, optimal ways are investigated to compress temporal data, while still providing practically random access to any past reference on these data. Moreover, the problems of distributing the history, keeping the history of a system that evolves like a graph, keeping histories in limited space and other general historical queries (not indexed by time but instead using historical correlation) are analyzed. The results of this project will greatly impact the use of the recorded past history for different programmers or database users. Other applications of these results to be considered, include network management tools, animation storing and archiving the UNIX directory system.