Michael Wacey

Corporations have a tremendous amount of stored information. On top of this, new information is being created every day. A small but critical portion of this information is stored in highly structured and well-defined formats in relational databases. However, most of the information is on paper, in e-mail, in word processing documents, in spreadsheets, in PDF files, in engineering diagrams, and so on. Ever since the initial XML draft in 1996, there has been an ongoing discussion of the semantic Web. A Google search for the exact expression the semantic Web returns about 1.2 million Web pages. Clearly there has been and continues to be a lot of discussion about the semantic Web. However, the semantic Web is still being worked on. This is mainly because very little information on the Web has not been semantically tagged. It may be more prudent to start on a smaller s... (more)

XML and Data Warehousing

This article covers the use of XML in building a data warehouse. For the most part, XML has been promoted as a mechanism for exchanging relatively small amounts of data, such as orders and shipping documents. In this article I describe an approach we used for transferring large sets of data (e.g., all the accounts in a bank). The three key concepts are the definition of fields using XML, the use of a common metadata, and the use of an external CDATA section. Before covering the details, I'll introduce some data warehouse issues and show why XML is a good solution. My team built ... (more)

XML Schema May Not Always Be the Right Tool for the Job

Will many of the features in XML Schema be widely used? In particular, I agree that it is better to have an XML language for specifying document layout rather than the DTD language. On the other hand, I am not sure that the document layout should be strongly typed. The nightmare scenario is where a customer cannot place a large order because an XML document is invalid. Assume a company has an average order size of $50,000 dollars with a current order range of $3,000 to $220,000. It would be reasonable to set a criterion in the Purchase Order Schema for this company to set a total... (more)