Support of Historical References in Database

支持历史参考是一个重要的问题， 计算机科学和工程的几个领域。的 数据库版本控制问题的重要性（即，保持 和访问旧版本）已特别提到， 数据库社区的最新进展。在快速增长的 在面向对象编程领域，历史引用使 程序员创建新的对象的基础上以前的对象 版本.支持历史的传统方法 引用需要很大的空间或很长的重建时间 时间，使广泛使用这种参考禁止。 该项目提供了历史参考的有效支持， 也就是说，快速重建到任何过去的状态，而不牺牲 大量的存储空间。研究了新的最佳方法 压缩时间数据，同时仍然提供实际的 随机访问这些数据的任何过去参考。而且 历史的传播、历史的保存、 一个像图一样进化的系统，在有限的时间内保持历史 空间和其他一般历史查询（不按时间索引 而是使用历史相关性）进行分析。的 该项目的结果将极大地影响使用 记录不同程序员或数据库的过去历史 用户.这些结果的其他应用有待考虑， 包括网络管理工具、动画存储和存档 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Supporting historical references is an important problem in several areas of computer science and engineering.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 In the rapidly growing area of object oriented programming, historical references enable programmers to create new objects based on previous object versions. Traditional approaches to supporting historical references require either large space or long reconstruction times, making the extensive use of such references prohibitive. This project provides efficient support of historical references, i.e., fast reconstruction to any past state without sacrificing a large amount of storage space.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.