LINGUISTIC FOUNDATIONS FOR XML VIEW UPDATE

University Of Pennsylvania, Philadelphia PA

Investigators

Abstract

IIS-0534592 Benjamin C. Pierce <bcpierce@cis.upenn.edu> University of Pennsylvania Linguistic Foundations for XML View Update This 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.