Research for Query Optimization Based on XML Database

Statistics for Cost-Based XML Query Optimization

Cost-based query optimization (CBO) is a very important area for data management in general and for XML data management in particular. For native XML database management systems (XDBMS), CBO techniques are harder than for relational databases, because the underlying tree-based data model is much more complex and the relative order (document order) between XML elements (nodes) matters. In this p...

XML Query Algera for Cost-based Optimization

Several requirements for algebra suitable for e cient cost-based optimization are presented. It is shown that known XML algebras do not fully satisfy this requirements. A new algebra to satisfy better the requirements is introduced.

Query Optimization for XML

XML is an emerging standard for data representation and exchange on the World-Wide Web. Due to the nature of information on the Web and the inherent exibility of XML, we expect that much of the data encoded in XML will be semistructured: the data may be irregular or incomplete, and its structure may change rapidly or unpredictably. This paper describes the query processor of Lore, a DBMS for XM...

Overview of Query Optimization in XML Database Systems

Effective Schema-Based XML Query Optimization Techniques

Use of path expressions is a common feature in most XML query languages, and many evaluation methods for path expression queries have been proposed recently. However, there are few researches on the issue of optimizing regular path expression queries. In this paper, two kinds of path expression optimization principles are proposed, named path shortening and path complementing, respectively. The...