1.2 XML as an Information Domain
XML allows us to model information systems in a natural and intuitive way. This is because XML allows us to express information in ways that better match the way we do business. We now have an information-modeling mechanism that allows us to characterize what we want to do, rather than how we have to do it. XML simply does a much better job of reflecting the way the real world operates than the data-modeling mechanisms that preceded it. XML brings a number of powerful capabilities to information modeling:
Heterogeneity: Where each "record" can contain different data fields. The real world is not neatly organized into tables, rows, and columns. There is great advantage in being able to express information, as it exists, without restrictions.
Extensibility: Where new types of data can be added at will and don't need to be determined in advance. This allows us to embrace, rather than avoid, change.
Flexibility: Where data fields can vary in size and configuration from instance to instance. XML imposes no restrictions on data; each data element can be as long or as short as necessary.
XML is also self-describing and informationally complete; applications can use this feature to automatically build themselves with little or no programming required. Companies such as BEA, TIBCO, and Microsoft offer frameworks for building applications, with a minimum of effort, that use XML as the basis for expressing information. In environments like these, XML becomes a universal information-structuring tool where system components no longer need to be programmed separately as discreet silos of functionality. NeoCore offers an XML Management System (XMS) that brings an entirely transparent persistence mechanism to the fold, requiring no separate database design process, indexing instructions, or use-case predefinition. Moreover, NeoCore's XMS carries forward the characteristics of XML that make it powerful as an information domainheterogeneity, extensibility, and flexibility. All that is required to store, retrieve, and manage information is that it be expressed in XML, and that queries be expressed as XPath or XQuery patterns. This can have a profound effect on rapid application development efficiency, especially when changes have to be made. When we build XML-centric systems, we can often accommodate changes by modifying the underlying XML, and information system components will adjust themselves accordingly without the need for reprogramming.