LINGUISTIC FOUNDATIONS FOR XML VIEW UPDATE

benjamin C. Pierce bcpierce@cis.upenn.eduUniversity宾夕法尼亚的XML视图更新语言学基础这个项目探索了一种解决树结构数据（如XML）背景下经典视图更新问题的新方法。这个问题源于这样一个事实：对数据库视图的修改可能并不仅仅对应于对底层数据库的修改；需要一种确定“更新策略”的方法，该策略指导如何在数据库中反映视图更新。该方法是定义和实现一种双向查询语言，其中每个表达式都可以（从左到右）作为视图定义读取，也可以（从右到左）作为更新策略读取。该项目的主要具体成果——Harmony数据同步框架——将在开源许可下免费发布，并与流行的Unison文件同步器集成，后者目前是数万学术研究人员和其他用户计算和协作基础设施的关键组成部分。双向树转换语言的高质量实现将单独发布，供其他人在他们自己的工具中使用，这些工具可能包括组日历系统、XML数据集成工具和结构化文档的协作编辑器。项目经费将支持培养1名博士生和数名本科生研究实习生。软件工具和描述它们的技术论文都将通过该项目的网站：http://www.cis.upenn.edu/~harmony发布。

IIS-0534592Benjamin C. Pierce bcpierce@cis.upenn.eduUniversity of PennsylvaniaLinguistic Foundations for XML View UpdateThis project explores a novel approach to the classical VIEW UPDATE PROBLEM in the context of tree-structured data such as XML. The problem arises from the fact that modifications to a database view may not correspond uniquely to modifications on the underlying database; a means of determining an "update policy" that guides how view updates are reflected in the database is needed. The approach is to define and implement a BI-DIRECTIONAL query language, in which every expression can be read both (from left to right) as a view definition and (from right to left) as an update policy.The project's main concrete deliverable---the Harmony data synchronization framework--will be distributed freely under an open-source license and integrated with the popular Unison file synchronizer, currently a key component of the computing and collaboration infrastructure for tens of thousands of academic researchers and other users. A high quality implementation of the bi-directional tree transformation language will be distributed separately for use by others in their own tools, which might include group calendaring systems, XML data integration tools, and collaborative editors for structured documents. Project funds will support the training of one PhD student and several undergraduate research interns. Both the software tools and the technical papers describing them will be disseminated through the project's web site: http://www.cis.upenn.edu/~harmony.