Title page for ETD etd-082305-120333

Document Type	dissertation
Author Name	El-Sayed, Maged F
Email Address	maged at cs.wpi.edu
URN	etd-082305-120333
Title	Incremental Maintenance Of Materialized XQuery Views
Degree	PhD
Department	Computer Science
Advisors	Elke A. Rundensteiner, Advisor Murali Mani, Co-Advisor Carolina Ruiz, Committee Member Jayavel Shanmugasundaram, Committee Member Michael A. Gennert, Department Head
Keywords	XML XQuery Incremental View Maintenance
Date of Presentation/Defense	2005-08-09
Availability	unrestricted
Abstract Keeping views fresh by maintaining the consistency between materialized views and their base data in the presence of base updates is a critical problem for many applications, including data warehousing and data integration. While heavily studied for traditional databases, the maintenance of XML views remains largely unexplored. Maintaining XML views is complex due to the richness of the XML data model and the powerful capabilities of XML query languages, such as XQuery. This dissertation proposes a comprehensive solution for the general problem of maintaining materialized XQuery views. Our solution is the first to enable the maintenance of a large class of XQuery views including XPath expressions, FLWOR expressions, and Element Constructors. These views may contain arbitrary result construction and arbitrary grouping and join operations. Our solution also supports the unique order requirements of XQuery including source document order and query order. The contributions of this dissertation include: (i) an efficient solution for supporting order in XML query processing and view maintenance, (ii) an identifier-based technique for enabling incremental construction of XML views, (iii) a mechanism for modeling and validating source XML updates, (iv) a counting algorithm for supporting view maintenance on delete and modify updates, (v) an algebraic solution for propagating bulk XML updates, and (vi) an efficient mechanism for refreshing materialized XML views on propagated updates. We provide proofs of correctness of our proposed techniques for materialized XQuery maintenance. We have implemented a prototype of our view maintenance solution on top of the Rainbow XML query engine, developed at WPI. Our experiments confirm that our solution provides a practical and efficient solution for maintaining materialized XQuery views even when handling heterogeneous batches of possibly large source updates. Our solution follows the widely adopted propagate-apply framework for view maintenance common to all mainstream query engines. That is, our solution produces incremental maintenance plans in the same algebraic language used to define the views. These plans can thus be optimized and executed by standard query processing techniques. Being compatible with standard frameworks paves the way for our XML view maintenance solution to be easily adopted by existing database engines.
Files	dissertation.pdf

Browse by Author | Browse by Department | Search all available ETDs