Optimizing XML path queries over relational databases.

摘要

The amount of data available on the Internet grows rapidly, and data becomes semistructured. The Extensible Markup Language (XML) has become a very important standard for data representation and exchange over the Internet. Therefore, a mechanism for managing XML documents is needed. A strong candidate is relational databases, for which management issues are solved. However, relational technology fails to deliver good performance for regular path queries, which are the distinctive features of XML query languages.; This thesis was developed within the ToX project. In this thesis, we present the ToX Relational mapping scheme which corresponds to the ToX relational backend. Along with the mapping itself, we propose a set of optimizations to efficiently evaluate regular path queries. We explore the use of an encoding for determining containment relationships, and the use of materialized views as a query optimization tool. We accompany the exposition with an experimental evaluation.