R树家族的演变和发展

近年来，针对空间数据库索引的研究引起了人们越来越多的兴趣和关注．为了快速、有效地处理存储于空间数据库中的海量空间数据，专家学者提出了大量的基于磁盘的空间索引方法．其中，1984年由Guttman提出的R树是目前最流行的动态空间索引结构，广泛应用于原型研究和商业应用中．其后，人们在此基础上针对不同空间运算提出了不同改进，经过20年的发展，不断产生的R树变体逐渐形成了一个枝繁叶茂的空间索引R树家族．该文回顾了R树及其各种主要变体；描述了基于R树的各种批量操作、空间查询处理算法、查询代价模型及查询优化过程；介绍了基于R树的并行处理、并发控制与锁定策略等方面的进展；并且分析了R树的未来研究方向．

The Evolvement and Progress of R-Tree Family

In recent years, the research on spatial indexing is arousing more and more inte rests and attentions. A number of spatial indexing structures based on secondary memory have been proposed for handling the massive spatial data stored in the s patial database rapidly and efficiently. R-tree, proposed by Guttman in 1984, i s the most popular dynamic spatial access method and has been widely used in man y prototype researches and commercial applications. During the last two decades, more and more R-tree variations have come into being a prosperous R-tree fami ly. In this paper, authors recall the R-tree and its main variations, study the bulk operation, spatial query processing, cost model and query optimizing techn ique based on R-tree, present the progress about the parallelism, concurrency c ontrol and locking strategy based on R-tree, and point out the directions for f uture work.