Databases and Database Users
Lecture 1
Topics covered
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Database concept
DBMS
University database
Query
Characteristics of DB
Advantage
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Database: Traditional Database Application
Banking
Online Shopping
Airline Reservation
In which most of the information that’s
stored and accessed is either textual or
numeric
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Multimedia Database Application
Stored Video
Thumb Print
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Different Applications of Database
• Geographic Information System (GIS): Store and analyze maps,
weather data and satellite images
• Online Analytical Processing (OLAP): Extract and analysis business
information to support decision making
OLAP
GIS
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Different Applications of Database: Internet
Popular Web Sites
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Use of Database
• Almost all areas where computer is used:
Business
Electronic Commerce (E-commerce)
Engineering
Medicine
Genetics
Law
Education
Library Science etc...
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Database
• Collection of related data.
• Data: Known facts that can be recorded and have implicit
meaning i.e. name, address, telephone numbers.
• So, Collection of related data with an implicit meaning is a
database.
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Database Properties
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Represent some aspects of real world (miniworld or universe of discourse -UoD).
[Source]
Changes in miniworld reflected in DB (Database) i.e. got promotion.
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Logically coherent collection of data with inherent meaning. [Interaction With Real
World]
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Designed, build and populated with data for a specific purpose for intended group
of users. [Audience]
Large Commercial Database: Amazon.com
• Contains: 20 million books, CDs, videos, games, electronic and other items
• Database Size: 2 terabytes
• Server: 200
• Visitors: 15 million/day
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Database Management System
• Collection of programs that enables user to create and maintain database
Purpose
Defining, Constructing, Manipulating, Sharing among users
• Defining or meta-data: Specifying data types, structure, length, field,
column and etc.
• Constructing: Process of storing data
• Manipulating: Querying data to retrieve, updating and generating reports.
• Sharing: Allows multiple users and programs
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Application Program
• Access database by sending queries or request for data to the DBMS
• Application terms
Query: Cause some data to be retrieve
Transaction: Cause some data to be read and written into DB
• Protection
System Protection: Against Hardware and Software crash
Security Protection: Against unauthorized and malicious access
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Database System: DB and DBMS
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Example: UNIVERSITY Database Tables
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UNIVERSITY Database
• Data Records: Records of same type i.e. STUDENT table stores data on
each student
• Data Elements: Represent the incident i.e. STUDENT table stores data
to represent name, Student_number, class and major
• Data Types: Represent the type of data i.e. Name of student is a String
of alphabetic characters or Grade can be a single Character such as A,
B, C.
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Relationship Concept
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Relationship Concept
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Querying and Updating Concept
Query
• Retrieve the transcript – a list of all courses and grades of “Smith” of Fall 08
Name
Student_number
Course_name
Course_code
Section_identifier
Grade
Smith
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Discrete
Mathametics
MATH2410
112
B
Smith
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Intro to
Commputer
Science
CS1310
119
C
• List the names of students who took the section of the “Database” course
offered in fall 2008 and their grades in that section
Name
Student_number
Course_name
Course_code
Section_identifier
Grade
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Querying and Updating Concept
Query
• List the names of students who took the section of the “Data Structure”
course offered in spring 2008 and their grades in that section
Name
Student_number
Course_name
Course_code
Section_identifier
Grade
Course_name
Course_code
Section_identifier
Grade
• Transcript of Fall 2008
Name
Student_number
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Querying and Updating Concept
Update
• Create new section for the Database course for this semester
• Enter a grade of “A” for Smith in “Database” section of Fall’09
Solution
Enter the course info in SECTION table
Than, enter grade on GRADE_REPORT table
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Phases: Designing A Database
• Requirement specification and analysis
– Requirements are documented
• Conceptual design
– Using tools for maintain, modify and transform into DB [ER]
• Logical design
– Using data model (RDMS)
• Physical design
– Storing and accessing DB
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Characteristics of DB
• Self describing nature
– Meta data or Database catalog
• Insulation between programs and data, and data abstraction
– Program data independence
• Support for multiple views
– Virtual data
• Sharing and multiuser transaction
– Multi user access at a time
– Transaction: executing program through reading, updating
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Actors
• Database administrator
– Oversee and manage the recourse
– Authorising access, coordinating
– Prevent security breaches
• Database designer
– Design and choose appropriate structure
– Identifying data and relationships
• Software engineer
– Analyse end user requirements
– Develop application program
• End user
– Querying, updating and generating reports
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Advantages
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Controlling redundancy
Restricting unauthorised access
Efficient query processing
Backup and recovery
Multiple user interface
Representing complex relationship
Flexibility
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Homework
Think and write about another database and that’s table
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Meta Data
BACK
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Multi view: Different from one another
BACK
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