1. Universita’ di Milano Bicocca Carlo Batini Course in Data Base Design
Part 1 – Introduction to Data Bases

2. © Carlo Batini, 2015
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3. High level conceptual map

4. Low-level conceptual map

5. A thermometer

6. Organizational system and Information System
Input: Goods or
requests of Services
Output: Goods or
delivered Services
Processes
Human Resources
Infor-
mation
ICT Technologies
Hardware
Software
Network
Data
Information System

7. Computer structure

8. Two tables

9. Two tables

10. Two software applications using data
Courses of Professors
Salaries of Professors
Course Assignment
Salary Management

11. The new set of tables

12. The data base approach Courses Course Assignment Professors
Salaries
Course Assignment
Salary Management
Professors

13. Database Management Systems allow concurrent and efficient access to the data base
Courses
Salaries
Course Assignment
Salary Management
Professors
Database
Management
System

14. The new set of tables Salaries Professors Courses Level Yearly Salary1
20.000 2
25.000 3
30.000 4
35.000
Course #
Prof Id
Prof. Surname
Level 37 1 Xu 4 29 16 2
Smith 3
Courses
Student Id
Prof Id
Grade 37 1 80 29 95 16 2 85

15. The new set of tables

16. Database Management System and its relationship with a computer
Software applications
Users
DBMS
Secondary Memory
Computer

17. Hierarchical and relational models of data
Student Id
Course Id
Grade
12127 37 80 29 90 18 85
23344 95
Student Id
Course Id
Grade
12127 37 80 29 95 18 85
23344

18. Hierarchical Relational Student Id Course Id Grade 12127 37 A 29 C 18B
23344
Student Id
Course Id
Grade
12127 37 A 29 C 18 B
23344

19. Databases as representation of a piece of reality using a data model

20. A relation (or table)

21. Reality, database, schema and instance
Representation
Model
Database
Concepts
Schema
Values of
concepts
Instance

22. Exercise 1.1 - Given the following database, reply to the following questions

23. Design phase of the Database life cycle
Database schema
Schema Design
Students, with
Student Id and Surname
Relational model
Student (Student Id, Surname)

24. Instance update phase

25. Student Data Schema Data Values Student Id Course Id Grade 12127 37 8029 95 18 85
23344
Data Values

26. DB Design LC Conceptual design Conceptual schema Logical design
Logical schema
Relational model
Conceptual design
Requirements
Entity Relationship Model
DB Design LC

27. Assume we are in a Chinese University (where grades are among 0 and 100). You want to represent:
three exams passed by a student with Student Id = referring to:
1. Course with Course Id = 37 and exam passed with grade 80.
2. Course with Course Id = 29 and exam passed with grade 90.
3. Course with Course Id 18 and exam passed with grade 85.
one exam passed by a student with Student Id = referring to:
1. Course with Course Id = 29 and Exam passed with grade 95.

28. Query phase Database instance Query Query language
E.g. Which surname has the Student
with StudentId = 29?
Table result of query
E.g. Xu

29. Databases as representation of a piece of reality using a data model

30. Central Processing Secondary Memory Unit Channels Main memory Input
10-8/10-9
seconds
10-2
External
World
Input
Output
Devices

31. Conceptual design and Logical design
Conceptual schema
Logical design
Logical schema
Relational model
(closer to the DBMS)
Conceptual design
Requirements
Entity Relationship Model
(closer to the user)
Conceptual design and Logical design

32. Concepts introduced in Part 1

33. Resti

34. Student Schema Data Student Id Course Id Grade 12127 37 80 29 95 18 85
23344
Data

35. Student Data Schema Data Values Student Id Course Id Grade 12127 37 8029 95 18 85
23344
Data Values

36. Design phase of the Database life cycle

37. Instance Update phase Database schema Create and update
Relational instances
Manipulation language
Relation instance
(e.g.
Student Id = 37, Surname = Wang
Student Id = 29, Surnaqme = Xu
Database Instance

38. three exams passed by a student with Student Id = 12127 referring to:
Assume we are in a Chinese University (where grades are among 0 and 100). You want to represent:
three exams passed by a student with Student Id = referring to:
1. Course with Course Id = 37 and exam passed with grade 80.
2. Course with Course Id = 29 and exam passed with grade 90.
3. Course with Course Id 18 and exam passed with grade 85.
one exam passed by a student with Student Id = referring to:
1. Course with Course Id = 29 and Exam passed with grade 95.
Assume we are in a Chinese University (where grades are between 0 and 100). You want to represent:
three exams passed by a student with Student Id = referring to:
1. Course with Course Id = 37 and exam passed with grade 80.
2. Course with Course Id = 29 and exam passed with grade 90.
3. Course with Course Id 18 and exam passed with grade 85.
one exam passed by a student with Student Id = referring to:
1. Course with Course Id = 29 and Exam passed with grade 95.

39. Modeling Relational Model Student Student Id Course Id Grade 12127 37
Assume we are in a Chinese University (where grades are between 0 and 100). You want to represent:
three exams passed by a student with Student Id = referring to:
1. Course with Course Id = 37 and exam passed with grade 80.
2. Course with Course Id = 29 and exam passed with grade 90.
3. Course with Course Id 18 and exam passed with grade 85.
one exam passed by a student with Student Id = referring to:
1. Course with Course Id = 29 and Exam passed with grade 95.
Relational
Model
Modeling
Student
Student Id
Course Id
Grade
12127 37 80 29 95 18 85
23344

40. Courses
Course Assignment
Professors
Salary Management
Salaries

41. Hierarchical and relational models of data
Student
Student
Student Id
Course Id
Grade
12127 37 80 29 90 18 85
23344 95
Student Id
Course Id
Grade
12127 37 80 29 90 18 85
23344 95
Hierarchical Model
Relational Model