1. Copyright © 2003 Addison-Wesley Timeline for Database Systems Developments before 1960 transition from punched card and tape 1960s, from file management to databases –Bachman (GE) IDS and data structure diagrams –IMS from IBM, Hierarchical Data Model –IMS DB/DC, Network Model and communication –SABRE, multi-user access with network 1970s, CODASYL and Relational Model –Codd (IBM) Relational Model –Chen introduced Entity Relationship Model –Query languages developed (SQL) 1980s, Client/Server DBs, Oracle, DB2 –PC databases, DBase, Paradox, etc. –SQL standard for definition and manipulation 1990s, web-based information delivery –Trends: expert DBs, object DBs, distributed DBs 2000s, Enhancing database technology for Web storage and access –Bioinformatics: genetic and protein information, medical records –Using the Web as a database

2. Copyright © 2003 Addison-Wesley How Do Databases Represent Information? Relational database management system (RDBMS) –Tables of data –Schema Name of table Names and types of attributes –Contents Row is a fact Attribute value is a characteristic

3. Copyright © 2003 Addison-Wesley Client Server Database Interaction

4. Copyright © 2003 Addison-Wesley Example of storing customer information Customer table accountIdlastNamefirstName 101BlockJane 102HamiltonCherry 103HarrisonKate 104BreauxCarroll Logical description (Schema) Customer (accountId, lastName, firstName) Table creation statement create table Customer (accountId integer, lastName char(20), firstName char(20))

5. Copyright © 2003 Addison-Wesley Who Works with Database Systems? Database designers Applications developers Web-application developers Web-site designers Database administrators System Analysts End users Application Programmers

6. Copyright © 2003 Addison-Wesley How Do Databases Support the World Wide Web? Maintain information that is published in the site Track the ways in which site visitors use that information Track the number of site visitors and customers Store information collected from input forms such as requests for customer addresses Store the structure and content of Web pages Sample: http://www.web4data.com/bighit/reservation.asp?accoun tId=101 http://www.web4data.com/bighit/reservation.asp?accoun tId=101