1. IT 20303 – DBMS Concepts Relational Database Theory

2. The Database Environment –Evolution of Computing Technology Punch-Cards – 1950-60s Character Based VDU – 1960-70s GUI – 1980-90s Voice/Telephony – 1990-Beyond

3. Relational Database Theory The Database Environment –Evolution of Processing Environments Batch Processing – 1950-60s Online – 1970-80s Networked – 1980-90s Future ? – 2000-beyond

4. Relational Database Theory Computing Technology based on Advances in: –Hardware – economics and miniaturization Continues to provide increasing power at decreasing costs Enables a broad range of powerful servers and workstations

5. Relational Database Theory Computing Technology based on Advances in: –Software – availability & capabilities Off-the-Shelf applications software Software to support all phases of application development

6. Relational Database Theory Computing Technology based on Advances in: –Connectivity – networking & internet Creates demand for web-enabled applications Allows interaction with many systems & databases

7. Relational Database Theory Database Technology Evolution –Files – 1950-60s –Hierarchical – 1960-70s –Network – 1970-80s –Relational – 1990-beyond

8. Relational Database Theory Database Technology –Relational is the dominate database technology –Importance of business rules is widely recognized –Importance, use, and amount of data is increasing

9. Relational Database Theory Database Technology –Our understanding of the nature of data is expanding Scalar (traditional) data: numbers, character strings, dates Complex data: graphics, images, geographic data, audio, video, documents

10. Relational Database Theory Database Technology –Relational DBMS capabilities are being extended To handle larger volumes and complex data

11. Relational Database Theory Database Technology –Trend is to provide a GUI to the database –Accessing the database via the web

12. Relational Database Theory Impact of Technology Advances –Systems are user-oriented rather than machine-oriented –Rate of new technology & product introduction is very fast –People use computers, databases, & the internet to do their jobs

13. Relational Database Theory Impact of Technology Advances –Conducting business on the internet is vital to most organizations –Still working to provide easier user access to data –Still seeking better ways to turn data into useful information

14. Relational Database Theory Database Environment – Introduction –Components: Data Users Network Software Hardware Administration

15. Relational Database Theory Database & the DBMS –What is a Database? A collection of related data Intended for use by a known group of users Designed & built for a specific set of requirements Represents (or models) some aspect of the real world

16. Relational Database Theory Database & the DBMS –What is a database management system (DBMS)? A collection of programs Enables users to create, maintain, & access a database

17. Relational Database Theory Why use a Database & a DBMS? –A database supports data sharing Many users access the same data Minimizes duplicated data and resulting update inconsistencies

18. Relational Database Theory Why use a Database & a DBMS? –An RDBMS is a productivity tool Provides efficient storage and access techniques Provides a standard databse access language, SQL –Many development & case tools interface to RDBMSs

19. Relational Database Theory Why use a Database & a DBMS? –An RDBMS provides centralized control of operational data Restricts access to authorized users: security Supports recovery of data in case of failure: durability

20. Relational Database Theory Why use a Database & a DBMS? Provides access by multiple users at the same time: concurrency Supports business rules about data values, relationships: integrity

21. Relational Database Theory Different Groups of Users work with Databases –Data Administration –End Users –Data Analyst –Business Systems Analyst –Systems Analyst –Programmer Analyst –DBA

22. Relational Database Theory End Users are at all levels in the organization –End Users’ primary job function is not programming Need information to answer questions, make decisions, etc. Provide input for data and process requirements Scattered throughout the organization

23. Relational Database Theory Analysts –Business Systems Analyst Expertise in business operations Develop specifications, process models for applications

24. Relational Database Theory Analysts –Systems Analyst Expertise in business applications development Develop specifications, models, and applications

25. Relational Database Theory Analysts –Data Analyst Expertise in business applications, especially data usage

26. Relational Database Theory Analysts –Programmer Analyst Expertise in programming, application development/maintenance –Uses VB, C++, etc. Support day-to-day operations of the enterprise

27. Relational Database Theory Database Administrator (DBA) –Interfaces with Users –Builds and Populates the database –Manages disk storage, backup, & recovery –Maintains passwords & access authorization

28. Relational Database Theory Database Administrator (DBA) –Monitors performance & responds to changing needs –Installs new releases of the RDBMS & related products –Keeper of the Data Dictionary

29. Relational Database Theory Database Administration –Develops high-level data architecture –Supports current & expected business functions –Responsible for a global view of all the enterprise’s data

30. Relational Database Theory Database Administration –Overall data architecture can have many subject databases One or more subject databases can have one or many DBAs –Integral to Information Resource Management (IRM) philosophy

31. Relational Database Theory Uses of a Database –Production Database Used to accomplish business functions of an organization –Online or batch applications –Objective is reliable, timely, valid processing of data

32. Relational Database Theory Uses of a Database Database usage includes CRUD activities –Creating, Reading, Updating, & Deleting data (CRUD) –Sometimes referred to as online complex processing

33. Relational Database Theory Uses of a Database Required features of DBMS often include: –Security –Recovery –Concurrency –Transaction Processing

34. Relational Database Theory Uses of a Database –Decision-Support Database Used for analysis, querying, & reporting –Read-Only –Sometimes referred to as OnLine Analytical Processing (OLAP)

35. Relational Database Theory Uses of a Database Required features of DBMS environment often include: –Easy-to-Use query tools or custom applications

36. Relational Database Theory Uses of a Database Data Warehouse –An approach to providing a database for querying and analysis

37. Relational Database Theory Uses of a Database –Individual Use Database A DBMS & a database in the individual user’s workstation –Single-User environment

38. Relational Database Theory Uses of a Database Initially mass-consumer-oriented –Example: dBASE, Paradox, FoxPro, Access RDBMS vendors introduced personal versions: –Personal Oracle (Free) –IBM DB2/2 – ($600/year) –Sybase SQL Anywhere – ($200)

39. Relational Database Theory Uses of a Database Required features often include ease of: –Installing, Use –Reporting –Producing simple applications

40. Relational Database Theory The Database Development Process –Requirements –Analysis/Design –Produce –Build/Test –Production Maintenance

41. Relational Database Theory Roles in Application & Database Development - Logical –Data Data Administration Data Analyst –Conceptual Data Models »ERDs »Created with help of the Users

42. Relational Database Theory Roles in Application & Database Development - Logical –Process Business Systems Analyst Systems Analyst –Process Model »DFD, Action Diagrams, Process Specification Diagrams

43. Relational Database Theory Roles in Application & Database Development – Physical –Data Database Administrator –Database

44. Relational Database Theory Roles in Application & Database Development – Physical –Process Programmer Analyst –Program Code