The aim of query processing is to find information in one or more databases and deliver it to the user quickly and efficiently. Traditional techniques work well for databases with standard, single-site relational structures, but databases containing more complex and diverse types of data demand new query processing and optimization techniques.

Most real-world data is not well structured. Today's databases typically contain much non-structured data such as text, images, video, and audio, often distributed across computer networks. In this complex milieu
(typified by the world wide Web), efficient and accurate query processing becomes quite challenging.

Principles of Database Query Processing for Advanced Applications teaches the basic concepts and techniques of query processing and optimization for a variety of data forms and database systems, whether structured or unstructured.