基于XML的数字地下空间索引QR树研究

Digital underground spatial indexing QR-tree based on XML

为了提高数字地下空间数据库的存储效率与检索性能,设计基于可扩展标记语言(XML)的数字地下空间索引四叉矩形(QR)树.该索引将检索过程涉及到的空间限制在整个索引空间的某一部分,XML利用其结构化的特点,改进了传统QR树索引文档与数据结构之间需要序列化的缺点,改善了因数据激增而下降的查找性能;同时利用XML的可扩展性,实现对索引信息规范化、结构化的描述,实现索引文档存储和数据结构组织的显式描述,解决了QR树存储开销较高、结点上溢和下溢问题,实现QR树动态维护,提高索引的稳定性.

Quadrate-rectangle （QR） tree was designed based on extensible markup language （XML） in order to improve data query and storage efficiency of digital underground space database. QR-tree based on XML limited the queried targets into special space. QR-tree based on XML reduced the transition difficult between traditional QR tree indexing document and data structure and increased the capacity that traditional QR-tree fell down quickly followed magnanimous data increment by using XML＇s structural character. QR-tree based on XML used the extensible feature of XML, conducted regular and structural depiction of indexing information, put indexing document and data structure into explicit storage format, and achieved dynamic-steady operation of QR-tree for solving such problems as high node storing time and overflow or underflow of traditional QR-tree.