This lecture introduced databases and database management systems. It discussed how databases are used to organize address books, household budgets, book libraries, inventory, HR/payroll, and dynamic websites. The lecture covered flat-file and relational databases, and how relational databases improve performance over flat files. It also described database management systems, their functions like data housekeeping and querying, and the SQL language. Popular database examples like MySQL were listed. Finally, the lecture defined data mining as the process of extracting useful information from data, and discussed its uses in recommender systems and pattern mining.

1. Lecture 11
Introduction to Databases

2. Today’s lecture outline

3. Databases1

4. Where are databases used?
1) Maintaining address-books
2) Managing household budgets
3) Maintaining a home book-library
a.

5. Where are databases used?
b.
1) Inventory tracking system
2) Human resources/ payroll
3) Discipline specific databases

6. Where are databases used?
c.
1) Police
2) Vehicle Registery
3) Banks
4) Tax records/ National IDs
5) All dynamic websites

7. Where are databases used?
d.
1) Google
2) Amazon
3) Youtube
4) Websites having search facility

8. Databases Types2

9. Flat-file Databases2.a

10. Flat file tables
Student Reg. No.
ICT marks
Student Reg. No.
ECA marks
Student Reg. No.
Student Name
Home City
City
Province
Rural/ Urban

11. Student Reg. No. ICT marks
001 84
002 80
003 86
004 67
005 72
006 88
ICT instructor’s table
A record, row or a tuple
An attribute or a column

12. Student Reg. No. ECA marks
001 72
002 83
003 66
004 87
005 82
006 91
ECA instructor’s table

13. Student Reg. No. Student’s Name Home City
001 Ahmad Karachi
002 Mustafa Lahore
003 Hassan Sukhur
004 Qasim Peshawar
005 Tayyib Swat
006 Tahir Zhob
Training Branch’s table1
This column is shared between all tables till now

14. City Province
Rural/
Urban
Karachi Sindh Urban
Lahore Punjab Urban
Sukhur Sindh Rural
Peshawar NWFP Urban
Swat NWFP Rural
Zhob Balochistan Rural
Training Branch’s table2
This column is shared with the table before

15. One flat file database
Student Reg. No.
ICT marks
ECA marks
Student Name
Home City
Home Province
City—Rural/ Urban

16. 16
Q. Who’s the best student?
Suppose, we are interested to find
the highest scoring urban student.
Problem: Searching a text file will not be
efficient for large sizes of text file.
Reason: One has to search sequentially
through the entire file to gather desired info.
How can performance be improved?

17. Relational Databases2.b

18. Relational databases
Student
Reg. No.
ICT marks
Student
Reg. No.
ECA marks
Student
Reg. No.
Student
Name
Home City
City
Province
Rural/ Urban

19. Student
Reg. No.
ICT
marks
ECA
marks
001 84 72
002 80 83
004 67 87
New table generated
Total
marks
156
163
154
It’s easy to find the highest-scoring
rural student in the generated table

20. Relational Database Schema
Student
Reg. No.
ICT marks
Student
Reg. No.
ECA marks
Student
Reg. No.
Student
Name
Home City
City
Province
Rural/
Urban
In a relational database, the schema defines:
1) the tables,
2) the fields in each table, and
3) the relationships between fields and tables.

21. Databases
Management System3

22. What is a DBMS?
A database management system is a
software system that manages databases.
:
1) Data Housekeeping
(e.g., creating/ deleting/ backing up tables; data entry)
2) Data Sorting
3) Data Searching
4) Data Query Response and Report Generation

23. What is a DBMS?
A DBMS ensures the following:
1) Data Integrity (correctness and consistency)
 Type Integrity (e.g., char input instead of numeric)
 Limit Integrity (e.g., age cannot be negative)
 Referential Integrity (e.g., referred item must exist)
2) Data Accessibility (support for concurrency)
3) Data Security (proper access control)

24. Data querying: SQL
SQL is the standard database query language
SQL is a 4G Computer language (non-
procedural query specification language)
:
1) Database schema creation/ modification
2) Retrieving/ manipulating database data

25. SQL example
SELECT isbn, title, price, date
FROM Book
WHERE price > 100.00 AND (date = '2004-04-16' OR date =
'2005-04-16') ORDER BY title;
ISBN Title Author Edition InStock Price Date
… … … … … … …
… … … … … … …
… … … … … … …
… … … … … … …
… … … … … … …
… … … … … … …
… … … … … … …
The database table: Book

26. Popular DBMS4

27. Example DBMS: MySQL

28. Data Mining5

29. What is Data Mining?
Data mining is the process of (automatically)
extracting useful information from data
Also known as Knowledge Discovery in
Databases (KDD)
Data mining is used in:
1) Recommender systems
2) Pattern mining

30. Recommender Systems
Youtube Amazon

31. Pattern Mining
NZ team uses SAS data
mining software for making
team strategy

32. Today’s lecture summary

33. http://tinyurl.com/5hb8pp