Object-Based Semantic Partitioning for XML Twig Query Optimization

摘要

The increased deployment of the XML-based standard for representation and exchange in multi-disciplinary domains has enforced the need for a more effective way to deal with XML query processing. Since very limited attention has been given to the semantic nature of the XML data being processed, this paper focuses on a technique for XML query optimization, called Object-based Twig Query (OTQ), to utilize the semantic structure of the data being queried to process twig queries. A twig query, which is a type of query with multiple branches, requires complex processing due to the joins between multiple paths. Outperforms object-based data partitioning, which aims at leveraging the notion of frequently-accessed data subsets and putting these subsets together into adjacent partitions. It evaluates branched queries through two essential components: (i) OTQ indexing, which uses an object-based connection to construct its indices i.e. Schema index and Data index, and (ii) OTQ processing to produce the final results in optimal time. At the end of this paper, a set of experimental results for the proposed approach on arange of real and synthetic XML data, as well as a comparative study of a similar work in the area, is presented to demonstrate the effectiveness of OTQ optimization.