The document defines and discusses databases. It states that a database is a collection of interrelated data stored together to serve multiple applications. It also defines a database management system as a computer-based record keeping system. The document notes that databases overcome limitations of typical file processing systems like data redundancy, inconsistency, inability to share data, lack of standardization and insecure data. It discusses the advantages of databases like reduced redundancy, controlled inconsistency, shared data, standardized data, secured data and integrated data. Finally, it provides an overview of database design levels from external views to the conceptual and physical levels.

1. Database

2. 3/4/2010ThepowerpointTemplates.com2Database is a collection of interrelated data stored together to serve multiple applications .Database Management system is basically a computer based record keeping systemD E F I N I T I O N

3. A typical file processing system suffers from some major limitations like data redundancy, data inconsistency, unsharable data ,unstandardized data, insecure data incorrect data etc .On the other hand data base over comes all these limitations .3/4/2010ThepowerpointTemplates.com3Need for Database

4. 3/4/2010ThepowerpointTemplates.com4ADVANTAGES Reduced data redundancy Controlled data inconsistencyShared data Standardized data Secured data Integrated data

5. 3/4/2010ThepowerpointTemplates.com5end –user Person who is not a computer trainee but uses database to retrieve some informationTypes OfUsersAPPLICATION SYSTEM ANALYSTThis user is concerned about all of the databaseat the logical levelPHYSICAL STORAGE SYSTEM ANALYSTThis user is concerned with the physical implementation details of the database

6. ThepowerpointTemplates.com6DATABASE DESIGN VIEW1VIEW 2VIEW n …………...External levelCONCEPTUAL LEVELPHYSICAL LEVELDATABASE3/4/2010

7. 3/4/2010ThepowerpointTemplates.com7Sales officerPurchase officerView 1Item-namepriceView 2Item-namepriceExternal level(individual user views )Conceptual levelItem-number character(6)Item name character(6)Price numeric (5+2) Physical levelStored item length =40Item # type=Byte(6),offset=0,Index=lxName type=Byte(20),offset=6Price type=Byte(8),offset=0

8. 3/4/2010ThepowerpointTemplates.com8THANK YOU