1. Lecture 1 Introduction to Database
(updated 04/09/2016)

2. Objectives In this chapter, you will learn: Data vs information
What a database is?
Database Management System
File Systems and Databases

3. Data vs Information

4. Data vs. Information Data (singular or plural) are raw facts
Raw data - Not yet been processed to reveal the meaning
Building blocks of information
Information requires context to reveal meaning
Eg, 123° 43' " W
Raw data must be formatted for storage, processing, and presentation
Data are the foundation of information, which is the bedrock of knowledge

5. Data vs. Information (cont’d.)
Information produced by processing data
Information used to reveal meaning in data
Accurate, relevant, timely information is the key to good decision making
Good decision making is the key to organizational survival
Data management: focuses on proper generation, storage, and retrieval of data

6. Why do I care about databases?
Good decisions require good information derived from raw facts
Data is managed most efficiently when stored in a database
Databases solve many of the problems encountered in data management
Used in almost all modern settings involving data management:
Business
Research
Administration
Important to understand how databases work and interact with other applications

7. What a database is?

8. What a Database is?
A database is a collection of organized data which are collected over time. The data contains both user data and metadata.
User data: raw facts of interest to end user
They are student names, grades, salary etc.
Metadata: data about data
They are data type, relationship, date created, data modified, and file size and etc.
Metadata also known as system catalog and data dictionary
Database management system (DBMS)
Is a collection of software
Manages the database structure
Controls access to data stored in the database
More on this later

9. Database Management System

10. What is a Database Management System (DBMS)?
An integrated database environment
DBMS controls the access to the databases
DBMS eliminates most of file system’s problems
Current generation DBMS software:
Stores data structures, relationships between structures, and access paths
Defines, stores, and manages all access paths and components
Logically related data stored in a single logical data repository
Physically distributed among multiple storage facilities

12. Role of the DBMS Serve data to end user
Interact DBMS directly or indirectly
Use SQL to retrieve the data from the DBMS
Allow writing applications for other users
Java, C, C++, C# …
Allow designing, creating and maintaining the database with ease
Carry out the task by database administrator (DBA)

13. The Database System Environment

14. Advantages of Database Systems (1)
Allow sharing of data
Control of redundancy
Ensure data consistency
Improve data standards
More control over concurrency

15. Advantages of Database Systems (2)
Better data security
Improved data integrity
Better backup and recovery procedures
Fast development of new applications
Better data accessibility

16. Disadvantages of Database Systems
Increased costs
Management complexity
Maintaining currency
Vendor dependence
Frequent upgrade/replacement cycles

17. File Systems and Databases

18. A Simple Database Everyone Can Do – Flat File

19. Flat file When data grow, processing may be difficult
A dedicated program may create to read the flat file database
Read line by line, fields are separated using a separator
However, flat file database is subjected to structural, data dependence and data redundancy.

20. A Conventional File System

21. File System (1) Contents of each file folder are logically related
Manual file systems
Served as a data repository for small data collections
Cumbersome for large collections
Computerized file systems
Data processing (DP) specialist converted computer file structure from manual system
Wrote software that managed the data
Designed the application programs

22. File System (2)
Initially, computer file systems resembled manual systems
As number of files increased, file systems evolved
Each file used its own application program to store, retrieve, and modify data
Each file was owned by individual or department that commissioned its creation

23. Computerized File Systems

25. A Simple File System

27. File System Redux: Spreadsheet
Ubiquitous use of personal productivity tools can introduce the same problems as the old file systems
Microsoft Excel
Widely used by business users
Users have become so adept at working with spreadsheets, they tend to use them to complete tasks for which spreadsheets are not appropriate – database substitute

28. Problems with File System Data Processing
Lengthy development times
Difficulty of getting quick answers
Complex system administration
Lack of security and limited data sharing
Extensive programming

30. Contrasting Database and File Systems

31. Preparing for Your Database Professional Career

32. Question?

33. Which is the following businesses require database?
An ice-cream store
A tuition center
A computer hardware and repair store
A pharmacy
A car spare-part store
A florist store
A Real estate corporation
A clinic
A second hand car dealer
A furniture store