XML Databases: An Idea Whose Time has Finally Come

The demand for an efficient means to manage XML content is increasing proportionately with our increased dependence on XML-based applications, messaging and distributed computing. This white paper examines current market forces, available technology and the emerging XML landscape to gauge the value and, by extension, the demand for an XML-centric database that can sit alongside the many flavors of databases and repositories that are already standard issue in today’s enterprise. While existing databases and repositories are adding various degrees of XML support, specific functional and resource constraints make it unlikely that any one of these data stores will be able to meet all of the needs of an XML saturated enterprise. This paper proposes a working definition of an XML-centric database and suggests specific applications where its value should be greatest. XML Repositories: An Idea Whose Time has Finally Come XML Saturation XML may be everywhere, but it is not doing everything it can XML is the underlying language of the World Wide Web; there are hundreds of industry and special interest standards based upon XML; and there are thousands of software products that claim various levels of XML support. XML is truly everywhere. However, the full impact of XML has not been felt because, while XML may be everywhere, XML is not being used in all of the ways that it can and will. Usage Computing Standards Special Interest Standards Support Vendor Special Interest Enterprise Adoption Content Application Processing Business Processes Figure 1: The three dimensions of XML saturation As XML usage approaches a saturation point within the enterprise and across the Internet, its true nature as a game changing catalyst is undeniable and unavoidable. How can XML saturation be measured? It can be measured in terms of usage, support and adoption. Usage is a gauge of the number of XML standards and specifications being created and adopted. For example, how pervasive are XML standards in a particular software stack? Solutions architecture is continuously being transformed as developers monitor the ideas of groups like the W3C, which is transforming the architecture of the initial web with recommendations for its future development. Support can be examined across three levels: vendor-specific support for XML, special interest support of XML, and enterprise support of XML. For example, what level of XML support has an enterprise achieved? Does the enterprise rely upon applications that support XML internally or only as import and export formats? Does B2B processing leverage XML? Adoption refers to items like: what facets of an organization’s business are modeled in XML? Have they moved beyond the traditional semi-structured content to include processing information and/or macro business process management? Are best practices, process management and other proprietary knowledge encoded within their XML content? 1 Please refer to the Appendix for a more thorough discussion of XML saturation. www.gilbane.com 2 XML Repositories: An Idea Whose Time has Finally Come Enterprise infrastructure and B2B computing impact on XML saturation XML saturation is being driven by numerous factors. Three of the most important factors today are the rise of the corporate portal, the emergence of web services as a cornerstone of the enterprise infrastructure stack, and the specialization and virtualization of enterprise content management. If an organization is committing to and investing in any of these factors, the rate and extent of XML saturation will increase proportionately. The enterprise portal An enterprise portal assembles applications and collaborative workspaces within an enterprise web, indexes and organizes content, and rationalizes security and user information, all from multiple, distributed systems. What is clear is that a portal has to interact with broad cross-sections of communities and applications. XML is the obvious catalyst to manage the many layers of interaction and content. As such, the portal is a major accelerating force in XML saturation. Figure 2 maps the immediate impact of a portal solution on an enterprise and indicates the likely ongoing impact as the portal is itself more fully assimilated into the day to day operations of an enterprise. Usage Computing Standards Special Interest Standards Support Adoption Content Application Processing Business Processes Portals Increase XML Saturation Vendor Special Interest Enterprise Figure 2: Portals are mapped into the three dimensions of XML saturation. Portals provide immediate content-level adoption, with every vendor offering some level of XML support using a subset of the W3C recommendations. Further, portals have the potential to encapsulate business processes, provide enterprise level support and provide operational support for any number of special interest standards. If portals are a part of your strategy, you should also be planning for an increasingly XML saturated environment. Every portal offering has some level of XML support with some vendors offering their entire portal solution as a bundle of web services. Web Services and Distributed Computing A Web service is a software system whose public interfaces are defined and described using XML. Other systems interact with Web services as prescribed by their definitions using XML based messages. In short, web services offer Internet protocol-based distributed computing. The web has transformed the user’s experience and it will ultimately do the same for applications. As such, web services are a significant agent of change and are driving XML saturation. Like earlier distributed computing technologies that have preceded web services