DATA MODEL
by Izni Hakimi
1. Two Categories Of DBMS :
2. Evolution Of Data Model
3. First Generation from 1960s until 1970s.The model is File System.Examples,VMS/VSAM.It used mainly on IBM mainframe systems that managed records,not relationships.
4. Second Generation from 1970s.The model is Hierarchical and network data model.Examples,IMS,ADABAS,IDS-II.It used early database systems navigational access.
5. Third Generation from Mid 1970s to present.The model is Relational Data Model.Examples,DB2,Oracle,MS SQL-Server,MySQL.Conceptual simplicity entity relationship(ER) modelling and support for relational data modelling.
6. Fourth Generation from Mid 1980s to present.The model is Object-Oriented and Extended Relational.Examples,Versant,FastObjects.net,Objectivity/DB.It supports complex data and extended relational products,supports objects and data warehousing.
7. Next Generation from present to future.The model is XML.Examples,dbXML,Tamino,DB2 UDB,Oracle 10g,MS SQL Server.
8. Three Scheme Architechture of DBMS
9. External / View Level
10. Conceptual / Logical Level
11. Internal / Physical Level
12. Server Database : Offer organizations the ability to manage large amounts of data efficiently and enables many users to access and update the data simultaneously.Although its pricey, a server-based database can provide a comprehensive data management solution
13. Benefits Of Desktop Database : Easy management , Low running cost , Easy to use
14. Benefits Of Server Database : Flexibility , Powerful performance , Scalability
15. Desktop Database : Database system that is made to run on a single computer or PC.These simpler solutions for data storage are much more limited and constrained than larger data center or data warehouse systems, where primitive database software is replaced by sophisticated hardware and networking setups.
16. Define Data Model
17. an abstract model that organizes elements of data and standardizes how they relate to one another and to properties of the real world entities.
18. Object Based Logical Model : E-R Model
19. The entity-relationship model is based on a perception of the world as consisting of a collection of basic objecrs (entities) and relationships among these objects
20. The overall logical structure of a database can be expressed graphically by an E-R diagram
21. Record-Based Logical Models : The Hierarchical Data Model, The Netwrok Data Model, Relational Data Model.
22. The Hierarchical Data Model : the entities are represented in a hierarchicak fashion. Identify a parent entity and its child entity. This model can be imagined as folders inside a folder.
23. The Network Data Models : the enhanced version of hierarchical data model. It is designed to address the drawbacks of the hierarchical models. This model is also represented as hierarchicak, but this model will not have single parent concept.
24. The Relational Data Models : Designed to overcome the drawbacks of hierarchical and networks model. Its designed completely different from those two models. Those models define how they are structured in the database physically and how they are inter-related.
25. Client Server Architechture Of DBMS
26. the system functionality is distributed between two types of modules.1 A client module is typically designed so that it will run on a user workstation or personal computer. Typically, application programs and user interfaces that access the database run in the client module
27. User Of DBMS
28. End User : the people who interact with database management system to perform different operations on database.
29. Application Programmer : the people who write application programs in programming languages (such as Visual Basic , Java or C++)to interact with databases.
30. Database Administrators : person who is responsible for managing the overall database management system.
