14、Containment Testing of XPath Queries

Containment Testing of XPath Queries

1. Introduction

XPath is a query language designed to navigate and select elements within XML documents. One of the critical challenges in XML query optimization is determining whether one XPath query is contained within another. This concept, known as query containment, is essential for various tasks such as query optimization, view maintenance, and schema matching. In this blog post, we delve into the details of containment testing for XPath queries, exploring the definition of query containment, the importance of query equivalence, the algorithms and techniques used for testing containment, and the computational complexity involved.

2. Definition of Query Containment

Query containment is a fundamental