数据库的空间组织

数据库的空间组织(中文3300字,英文1800字)
摘要：本文简要的介绍了数据库系统的查询登记修改，单一数据库及多个数据库模式，简述了使用数据库的安全性及必要性。
关键字：数据库系统/数据模式/安全性
二十年来空间数据管理一直是数据库研究领域的活跃区，研究的焦点集中在发展存储和检索空间数据的数据结构上。然而，没有商业数据库系统直接为定义和存储空间数据提供设备，明确地表达以空间数据为研究条件的查询。 因此存在下列诸多问题，在这些问题上，应把焦点集中在近期研究，（按照重要程度和迫切程度排列）。

Database of Space Organization
Spatial data management has been an active area of research in the database field for two decades，with much of the research being focused on developing data structures for storing and indexing spatial data. However, no commercial database system pro-vides facilities for directly defining and storing spatial data, and formulating queries based on research conditions on spatial data. We believe the following are the relevant issues on which near-term research should be focused (in the order of decreasing importance and urgency)．  
First, relational query optimization techniques need to be extended to deal with spatial queries，that is，queries that contain search conditions on spatial predicates to be developed.