Supporting Keyword Search over Structured Data

使用户能够使用简单的关键字访问数据库，可以减轻他们的麻烦，掌握结构化查询语言和理解复杂的，可能是快速发展的数据库模式。尽管关键字搜索技术在Web竞技场中已经成熟，但是支持对结构化数据（例如存储在数据库和数据仓库中的数据）的关键字搜索提出了独特的挑战。当在结构化数据上执行关键字搜索时，结果不再是现有的Web页面，而是通过组装来自（可能）不同表的关键字匹配元组而组成的“虚拟文档”。相应地，在搜索过程中必须探索的空间变得比在Web搜索中遇到的空间大得多。

Enabling users to access databases using simple keywords can relieve them from the trouble of mastering a structured query language and understanding complex and possibly fast evolving database schemas. Although keyword search technology has matured in the Web arena, supporting keyword search over structured data, such as the data stored in databases and data warehouses, presents unique challenges. When performing keyword search over structured data, the results are no longer existing Web pages, but "virtual documents" composed by assembling the keyword-matching tuples from (potentially) different tables. Correspondingly, the space that must be explored during search becomes much larger than that encountered in Web search.