The Extensible Markup Language (XML) is used to represent fine-grained data that originates in repositories
in machine readable format by providing structure and the possibility of adding type information,
such as XML Schema. A Web service is a software system that supports interoperable application-toapplication
interaction over the Internet. Web services are based on a set of XML standards, such as
Web Services Description Language (WSDL), Simple Object Access Protocol (SOAP), and Universal
Description, Discovery and Integration (UDDI). Each service makes its functionality available through
well-defined or standardized XML interfaces. The result of this approach is a Service-Oriented Architecture
(SOA). XML is playing an important role in the data transport protocol for Web services. For
example, SOAP messages are used both by service requestors to invoke Web services, and by Web
services to answer requests. This book aims to explore and investigate various research issues of XML
data and related applications that are encapsulated by Web services over the network. In particular, we
call these networked services as XML services.
Many commercial systems built today are increasingly using these technologies together and it is important
to understand the various research and practical issues. The goal of this book is to bring together
academics and practitioners to describe the use and synergy between the above-mentioned technologies.
This book is mainly intended for researchers and students working in computer science and engineering,
and for industry technology providers, having particular interests in XML services as well as for users
of Web service and grid computing technologies.
This book is structured as follows. Chapter I presents a XML technical framework for administrators
to dynamically update a valid XML document without interfering with other documents in the XML
database. Then Chapter II describes the mechanism of change detection on semi-structured XML data
with various efficient algorithms for the XML databases. Next, Chapter III discusses an active XML
transaction approach to support locking protocol, dynamic construction of undo operation and chaining
the active peers. Based on the fundamental technologies for handling XML databases, Chapter IV
proposes an XML search engine which accepts keyword-based queries and loosely structured queries.