Transforming SQL queries to operate on XML data.
XML (eXtensible Markup Language) is emerging as an increasingly important format for data interchange and storage. Querying against XML data sources is not yet mature, with two standards (XQuery and XSLT - eXtensible Stylesheet Language Transformations) growing to meet the needs of the user base. Neither of these languages has reached the penetration of SQL in the database community.
To that end, Drs Lakshmanan and Sadri, in their paper "On the Information Content of an XML Database," propose a method of creating a view of the contents of an XML document in relational form and a process for translating SQL queries based on that relational view into XQuery operating on the native XML document.
Dr. Sadri maintains a project page with more information.
Here, I build on the work done by Drs Lakshmanan and Sadri to broaden the range of queries supported and suggest some augmentations to some of their algorithms.
As part of my thesis, I also implemented a simple version of the program handling aggregates, IDREF(S), etc. on single table queries. Let me know if you're interested in it.