XML Data Management Native XML and XML-Enabled Database Systems

"This is an excellent book that combines a practical and analytical look at the subject.""--Leo Korman, Principal Software Engineer, KANA SoftwareAs organizations begin to employ XML within their information-management and exchange strategies, data management issues pertaining to storage, retrieval, querying, indexing, and manipulation increasingly arise. Moreover, new information-modeling challenges also appear. "XML Data Management--with its contributions from experts at the forefront of the XML field--addresses these key issues and challenges, offering insights into the advantages and drawbacks of various XML solutions, best practices for modeling information with XML, and developing custom, in-house solutions.In this book, you will find discussions on the newest native XML databases, along with information on working with XML-enabled relational database systems. In addition, "XML Data Management thoroughly examines benchmarks and analysis techniques for performance of XML databases.Topics covered include: The power of good grammar and style in modeling information to alleviate the need for redundant domain knowledgeTamino's XML storage, indexing, querying, and data access featuresThe features and APIs of open source eXistBerkeley DB XML's ability to store XML documents nativelyIBM's DB2 Universal Database and its support for XML applicationsXperanto's method of addressing information integration requirementsOracle's XMLType for managing document centric XML documentsMicrosoft SQL Server 2000's support for exporting and importing XML dataA generic architecture for storing XML documents in a relational databaseX007, XMach-1, XMark, and other benchmarks for evaluatingXML database performanceNumerous case studies demonstrate real-world problems, industry-tested solutions, and creative applications of XML data management solutions.Written for both XML and relational database professionals

Akmal B. Chaudhri works for IBM developerWorks, where he is also Zone Editor for Special Projects. A recognized authority on objects and databases, he has been a regular presenter at many international conferences, including OOPSLA and Object World. In addition, he has edited several books on these topics.

Awais Rashid is a Lecturer in the Computing Department of Lancaster University in the U.K. where he leads research into the application of new technologies, such as XML and aspect-oriented programming, and database systems. He has actively published on these topics and has organized a number of relevant international events.

Roberto Zicari is a full Professor for Databases and Information Systems at the Johann Wolfgang Goethe University in Frankfurt/Main, Germany. He is an internationally recognized expert in Object Technology. He has consulted and lectured in Europe, North America, and Japan.

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The past few years have seen a dramatic increase in the popularity and adoption of XML, the Extensible Markup Language. This explosive growth is driven by its ability to provide a standardized, extensible means of including semantic information within documents describing semi-structured data. This makes it possible to address the shortcomings of existing markup languages such as HTML and support data exchange in e-business environments. Consider, for instance, the simple HTML document in Listing P.1. The data contained in the document is intertwined with information about its presentation. In fact, the tags describe only how the data is to be formatted. There is no semantic information that the data represents a person's name and address. Consequently, an interpreter cannot make any sound judgments about the semantics as the tags could as well have enclosed information about a car and its parts. Systems such as WIRE (Aggarwal et al. 1998) can interpret the information by using search templates based on the structure of HTML files and the importance of information enclosed in tags defining headings and so forth. However, such interpretation lacks soundness, and its accuracy is context dependent. Listing P.1 An HTML Document with Data about a Person Person Information Name: John Doe Address: 10 Church Street, Lancaster LAX 2YZ, UK Dynamic Web pages, where the data resides in a backend database and is served using predefined templates, reduce the coupling between the data and its representation. However, the semantics of the data can still be confusing when exchanging information in an e-business environment. A particular item could be represented using different names (in the simplest case) in two systems in a business-to-business transaction. This enforces adherence to complex, often proprietary, document standards. XML provides inherent support for addressing the above problems, as the data in an XML document is self-describing. However, the increasing adoption of XML has also raised new challenges. One of the key issues is the management of large collections of XML documents. There is a need for tools and techniques for effective storage, retrieval, and manipulation of XML data. The aim of this book is to discuss the state-of-the-art in such tools and techniques. This preface introduces the basics of XML and some related technologies before moving on to providing an overview of issues relating to XML data management and approaches addressing these issues. Only an overview of XML and related technologies is provided because several other sources cover these concepts in depth. P.1 What Is XML? XML is a W3C standard for document markup. It makes it possible to define custom tags describing the data enclosed by them. An example XML document containing data about a person is shown in Listing P.2. Note that tags in XML can have attributes. However, for simplicity, they have not been used in this example. Listing P.2 An XML Document with Data about a Person Doe John 10 Church Street Lancaster LAX 2YZ UK Unlike the HTML document in Listing P.1, the document in Listing P.2 contains only the data about the person and no re