Database_Models objectives of DBMS .pptx

Database models and DBMS
Types of Database models and objectives of data base management system
Database Model
A set of rules and standards that define how data is organized.
Hierarchical Model
Network Model
Relational Model
DBMS
Collection of programs to create, maintain, and access databases.
Objectives of DBMS
Sharebility
Availability
Evolvability
Database Integrity

1. Database models and DBMS Types of Database models and objectives of data base management system

2. Objectives Define what a database model is. Describe the different types of database models. Define what a database management system (DBMS) is. Discuss the objectives of a DBMS.

3. Define Database Model A set of rules and standards that define how data is organized. Defines how users view the organization of data.

4. Types of Database Models Hierarchical Model Network Model Relational Model

5. Hierarchical Model Arranges records in a hierarchy like an organizational chart. Each record is called a node or segment . Nodes represent entities. Top-most node is called root . Higher level node: Parent Lower level node: Child Each child has one parent. Structure is often called an inverted tree .

6. Hierarchical Model diagram

7. Network Model Similar to hierarchical model. Child nodes can have more than one parent. Child nodes are represented by arrows. More complex diagrams. Provides more flexibility.

8. Network Model Diagram

9. Relational Model Most commonly used database model. More flexible than hierarchical and network models. Consists of simple relations (tables). Relations represent entities. Used to store information about entities. Relationships based on data of entities.

10. Relational Model Diagram

11. What is DBMS? Collection of programs to create, maintain, and access databases. Uses database manager software. Controls the overall structure of a database. Used by different organizations for various purposes.

12. Database management system

13. Objectives of DBMS Shareability Availability Evolvability Database Integrity

14. Shareability Fundamental objective of DBMS. Allows data to be shared by different people simultaneously. Data is stored centrally. Accessible from different locations. Reduces storage cost and ensures consistency.

15. Availability Users must be able to access data and DBMS easily. Data should be available when and where required.

16. Evolvability DBMS should facilitate changes due to increasing user requirements or technology changes. Changes may occur by contents or structure. Example: Structure change if an organization expands.

17. Database Integrity Ensures data entered is accurate and consistent. Data is shared among different users. Measures must be maintained to ensure integrity.

18. Conclusion Database models organize data efficiently. Different models offer various structures and flexibilities. Hierarchical, Network, and Relational models serve different needs. DBMS efficiently manages data. Objectives ensure data is shareable, available, adaptable, and consistent.