本书系统、全面地阐述了关于 XML数据检索和查询方面最新的研究成果，包括 XML数据的编码、索引、模式匹配，结果估计，关键词检索，查询改写等方面内容。本书主要强调内容的先进性，将作者最新的 XML数据查询和检索的最新成果涵盖进来，其中某些内容还未公开发表。本书主要面向系统开发人员，研究生和科研工作者，也可供其他读者学习使用，对专业人士可作为最新的技术参考资料。

Preface XML is short for eXtensible Markup Language, whose purpose is to aid information systems in sharing structured data, especially via the Internet, to encode documents, and to serialize data. The properties that XML inherited make it the widely popular standard of representing and exchanging data. When working with those XML data, there are (loosely speaking) three different functions that need to be performed: adding information to the repository, searching and retrieving information from the repository, and updating information from the repository. We focus on all three parts of functions. There are two decades since the beginning of XML, and this .eld has expanded tremendously ...