1. Datab ase Systems
Week 1 by
Zohaib Jan

2. About the course

3. About the course Ref Text Book:
Fundamentals of Database Systems 6th Edition by PEARSON PUBLISHERS

4. What is a data base ? A database is a collection of related data.
What is Data ?
Collection of records that have known meaning and are either facts or figures or have some meaning (ie Information)

5. What is DBMS
Database Management System is collection of programs that enable users to maintain and create databases.
The DBMS is a general-purpose software systemthat facilitates the processes of defining, constructing, manipulating, and sharing databases among various users and applications

6. DBMS
Defines
Creates
Manipulates

7. DBMS Provides Efficient, Reliable, Convenient, Safe, Multi User,
Storage to MASSIVE amounts of PERSISTENT data
What’s missing ?

8. DBMS
Access ?
How do you access data ?

9. What is most important to DBMS

10. DBMS

11. DBMS DBMS may be developed by using Frameworks…
DBMS may be used with Middlewares
Lastly may not be dependent on DBMS at all

12. Data Model How is your data stored ? Can be in forms of records
Can be in form of XML / JSON
Can be in form of Graph

13. Schema Structure of the Data and Data Base
Data will adhere to the Schema
Schema doesn’t change over time data does

14. DDL
Data Definition Language
Is used to define the schema

15. DML Data Manipulation Language
The language used to interact with your data

16. DBMS users Database Administrator Database Designer
Database Application Developer
Database Implementer

17. Advantages of USING DBMS
Controlling redundancy
Restricting Unauthorized Access
Providing Persistent
Providing Storage Structures and Search Techniques for Efficient Query Processing Storage for Program Objects
Providing Backup and Recovery
Providing Multiple User Interfaces
Representing Complex Relationships among Data
Enforcing Integrity Constraints

18. Further Reading
Chapter 1 of reference book

19. Data Model
A data model—a collection of concepts that can be used to describe the structure of a database

20. Categories of Data Model
High level or Conceptual data models – concept of data
Physical or low level models – how data is stored

21. High level / Conceptual data models
Entities
Attributes
Relationships

22. Entities
An entity represents a real-world object or concept, such as an employee or a project

23. Attributes
An attribute represents some property of interest that further describes an entity, such as the employee’s name or salary.

24. Relationship
A relationship among two or more entities represents an association among the entities, for example, a works-on relationship between an employee and a project

25. Entity Relationship Model
A high level conceptual data model

26. Relational Data Model
How data is represented in the DBMS
SQL

27. Object Data Model
A standard for object databases called the ODMG object model has been proposed by the Object Data Management Group (ODMG)

28. Schema

29. Three schema architecture
The internal level schema
The conceptual level schema
The view level schema

30. Data independence
The capacity to change the schema at one level of a database system without having to change the schema at the next higher level
2 types of data independence
Logical data independence is the capacity to change the conceptual schema without having to change external schemas or application programs
Physical data independence is the capacity to change the internal schema without having to change the conceptual schema. Hence, the external schemas need not be changed as well

31. Further Reading
Chapter 2 of reference book