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Lecture Database system concepts (6/e): Chapter 23 - Silberschatz, Korth, Sudarshan

XML provides a way to represent data that have nested structure, and furthermore allows a great deal of flexibility in structuring of data, which is important for certain kinds of nontraditional data. Chapter 23 covers the XML standard for data representation, which is seeing increasing use in the exchange and storage of complex data. The chapter also describes query languages for XML. | Chapter 23: XML Database System Concepts, 6th Ed. ©Silberschatz, Korth and Sudarshan See www.db-book.com for conditions on re-use XML Structure of XML Data XML Document Schema Querying and Transformation Application Program Interfaces to XML Storage of XML Data XML Applications Database System Concepts - 6th Edition 23.2 ©Silberschatz, Korth and Sudarshan Introduction XML: Extensible Markup Language Defined by the WWW Consortium (W3C) Derived from SGML (Standard Generalized Markup Language), but simpler to use than SGML Documents have tags giving extra information about sections of the document E.g. XML Introduction Extensible, unlike HTML Users can add new tags, and separately specify how the tag should be handled for display Database System Concepts - 6th Edition 23.3 ©Silberschatz, Korth and Sudarshan XML Introduction (Cont.) The ability to specify new tags, and to create nested tag structures make XML a great way to exchange data, not just documents. Much of the use of XML has been in data exchange applications, not as a replacement for HTML Tags make data (relatively) self-documenting E.g. Comp. Sci. Taylor 100000 CS-101 Intro. to Computer Science Comp. Sci 4 Database System Concepts - 6th Edition 23.4 ©Silberschatz, Korth and Sudarshan XML: Motivation Data interchange is critical in today’s networked world Examples: Banking: funds transfer Order processing (especially inter-company orders) Scientific data – Chemistry: ChemML, – Genetics: BSML (Bio-Sequence Markup Language), Paper flow of information between organizations is being replaced by electronic flow of information Each application area has its own set of standards for representing information XML has become the basis for all new generation data interchange formats Database System Concepts - 6th Edition 23.5 ©Silberschatz, Korth and .