XML:Managing data exchange

2 Central problems of data management Capture Storage Retrieval Exchange

3 EDI Electronic exchange of standard documents In use for some 20 years Standards ANSI X.12 (US and Canada) EDIFACT (International)

4 EDI: Advantages Paper handling is reduced, saving time and money Data can be exchanged in real time There are fewer errors since data are keyed only once Enhanced data sharing enables greater coordination of activities between business partners Money flows are accelerated and payments received sooner

5 EDI: Adoption Much information flow is still on paper Electronic exchange is the exception rather than the rule The Internet is a lower cost solution than EDI using value added networks (VANs)

6 SGML Document management consumes 15% of company revenue 25% of labor costs % of an office worker’s time Standard generalized markup language (SGML) was designed to reduce the cost of document management

7 Markup language Embedded information within text about the meaning of the text This uniquely creative collaboration between Miles Davis and Gil Evans has already resulted in two extraordinary albums— Miles Ahead CL 1041> and Porgy and Bess CL 1274.

8 SGML A vendor independent standard for publication of all media Cross system Portable Defines the structure of a document The parent of HTML and XML

9 SGML: Advantages Re-use Same advantage as with word processing Flexibility Generate output for multiple media Revision Version control

10 SGML code 16 XML: Managing Data Exchange Words can have no single fixed meaning. Like wayward electrons, they can spin away from their initial orbit and enter a wider magnetic field. No one owns them or has a proprietary right to dictate how they will be used. … …

11 HTML code 16 XML: Managing Data Exchange Words can have no single fixed meaning. Like wayward electrons, they can spin away from their initial orbit and enter a wider magnetic field. No one owns them or has a proprietary right to dictate how they will be used.

12 The problem with HTML Presentation not meaning Reader has to infer meaning Machines are not very good at inferring meaning

13 XML Extensible markup language SGML for e- and m-commerce A meta-language A language to generate languages Will steadily replace HTML

14 XML vs. HTML Structured text User-definable structure Context-sensitive retrieval Greater hypertext linkage Formatted text Pre-defined format Limited retrieval Limited hypertext linking

15 XML rules Elements must have both an opening and closing tag Elements must follow a strict hierarchy with only one root element Elements may not overlap other elements Element names must obey XML naming conventions XML is case sensitive

16 HTML vs. XML HTMLXML MIST7600 Data Management 3 credit hours MIST7600 Data Management 3

17 Processing shift From server to browser Browser can ‘read’ meaning of the data Less data transmitted HTMLXML Retrieve shirt data with prices in $US Retrieve shirt data with prices in euros Retrieve shirt data with prices in $US Retrieve conversion rate of $US to euro Retrieve Java program to convert currencies Compute prices in euros

18 Searching Search engines look for appropriate tags in the XML code Faster More precise

19 Expected gains Store once and format many times Hardware and software independence Capture once and exchange many times Accelerated targeted searching Less network congestion

20 Conclusion XML is a significant technological development Its main purpose is to support data exchange It will lower the cost of business transactions It will be a critical data management technology