Understand how the database approach is Understand how the database approach is different and superior to earlier data systems different and superior to earlier data systems

Examine how information demand and Examine how information demand and technology explosion drive database systems technology explosion drive database systems Trace the evolution of data systems and note Trace the evolution of data systems and note how we have arrive at the database approach how we have arrive at the database approach

Comprehend the benefits of database systems Comprehend the benefits of database systems and perceive the need for them and perceive the need for them

Survey briefly various data models, types of Survey briefly various data models, types of databases, and the database industry

1. Introduction to Data
and Information Management
(Database Management Systems IS331)
Lecture 1
Abdisalam Issa-Salwe
Taibah University
College of Computer Science & Engineering
Information Systems Department
Jeffrey A. Hoffer, et al: Modern Database Management, 8th Edition, 2007, Prentice Hall
2
ObjectivesObjectives
Understand how the database approach isUnderstand how the database approach is
different and superior to earlier data systemsdifferent and superior to earlier data systems
Examine how information demand andExamine how information demand and
technology explosion drive database systemstechnology explosion drive database systems
Trace the evolution of data systems and noteTrace the evolution of data systems and note
how we have arrive at the database approachhow we have arrive at the database approach
Comprehend the benefits of database systemsComprehend the benefits of database systems
and perceive the need for themand perceive the need for them
Survey briefly various data models, types ofSurvey briefly various data models, types of
databases, and the database industrydatabases, and the database industry

2. 3
About databaseAbout database
Today, almost all organizations depend on theirToday, almost all organizations depend on their
database systems for the crucial information theydatabase systems for the crucial information they
need to run their business.need to run their business.
In every industry across the board, from retail chainIn every industry across the board, from retail chain
stores to financial institutions, from manufacturingstores to financial institutions, from manufacturing
enterprises to government departments, and fromenterprises to government departments, and from
airline companies to utility businesses, databaseairline companies to utility businesses, database
systems have become the norm for informationsystems have become the norm for information
storage and retrieval.storage and retrieval.
Database systems form the centerpiece of theDatabase systems form the centerpiece of the
growing and maturing electronic commerce.growing and maturing electronic commerce.
Database and Web technologies have merged.Database and Web technologies have merged.
4
About database (contAbout database (cont……))
How were companies running their business beforeHow were companies running their business before
computers came into use?computers came into use?
Organizations needed information to execute theOrganizations needed information to execute the
business processes, sell goods and services, andbusiness processes, sell goods and services, and
satisfy the needs of customers.satisfy the needs of customers.
Manual files supported business operations.Manual files supported business operations.
Accounting personnel performed manualAccounting personnel performed manual
calculations and prepared invoices.calculations and prepared invoices.
Payroll departments manually wrote the checks.Payroll departments manually wrote the checks.

3. 5
About database (contAbout database (cont……))
From the 1970s onward, two striking and remarkableFrom the 1970s onward, two striking and remarkable
phenomena were distinctly observed. (Refer to Figure 1phenomena were distinctly observed. (Refer to Figure 1--11
indicating these two major developments).indicating these two major developments).
First, demand for information has escalated in everyFirst, demand for information has escalated in every
organization.organization.
Organizations have steadily become global and widespread.Organizations have steadily become global and widespread.
Organizations have to contend with fierce competitiveOrganizations have to contend with fierce competitive
pressures.pressures.
They need vast and complex information to stay in businessThey need vast and complex information to stay in business
and make a profit.and make a profit.
Second, the past three decades have witnessed a huge,Second, the past three decades have witnessed a huge,
explosive growth in information technology. Processors haveexplosive growth in information technology. Processors have
become faster, cheaper, and smaller.become faster, cheaper, and smaller.
6
About databaseAbout database
Information, as we know it today, includes bothInformation, as we know it today, includes both
electronic and physical information.electronic and physical information.
The organizational structure must be capable ofThe organizational structure must be capable of
managing this information throughout themanaging this information throughout the
information lifecycle regardless of source or formatinformation lifecycle regardless of source or format
(data, paper documents, electronic documents,(data, paper documents, electronic documents,
audio, video, etc.) for delivery through multipleaudio, video, etc.) for delivery through multiple
channels that may include cell phones and webchannels that may include cell phones and web
interfaces.interfaces.

4. 7
Information ManagementInformation Management
Information management is the collection andInformation management is the collection and
management of information from one or more sourcesmanagement of information from one or more sources
and the distribution of that information to one or moreand the distribution of that information to one or more
audiences.audiences.
Management means the organization of and control overManagement means the organization of and control over
the structure, processing and delivery of information.the structure, processing and delivery of information.
The organizational structure must be capable ofThe organizational structure must be capable of
managing this information throughout the informationmanaging this information throughout the information
lifecycle regardless of source or format (data, paperlifecycle regardless of source or format (data, paper
documents, electronic documents, audio, socialdocuments, electronic documents, audio, social
business, video, etc.) for delivery through multiplebusiness, video, etc.) for delivery through multiple
channels that may include cell phones and webchannels that may include cell phones and web
interfaces.interfaces.

5. 9
About databaseAbout database
Information assets are corporate assets. This principle
should be acknowledged or agreed upon across the
organization otherwise any business case and support
for IM will be weak.
Information must be made available and shared. Of
course not all information is open to anyone, but in
principle the sharing of information helps the use and
exploitation of corporate knowledge
Information the organisation needs to keep is managed
and retained corporately. In other words the retention
and archiving, of information.
If you save a document today, you expect it to be
secured and still available to you tomorrow
What a Database Is and Is Not
l your personal address book in a Word document
l a collection of Word documents
l a collection of Excel Spreadsheets
l a very large flat file on which you run some
statistical analysis functions
l data collected, maintained, and used in airline
reservation
l data used to support the launch of a space shuttle
The word database is commonly used to refer to any of
the following:
10

6. Models of Reality
REALITY
• structures
• processes
DATABASE SYSTEM
DATABASE
DML
DDL
l A database is a model of structures of reality
l The use of a database reflect processes of reality
l A database system is a software system which supports the
definition and use of a database
l DDL: Data Definition Language
l DML: Data Manipulation Language
11
Why Use Models?
Models can be useful when we want to examine or
manage part of the real world
The costs of using a model are often considerably
lower than the costs of using or experimenting with
the real world itself
Examples:
airplane simulator
nuclear power plant simulator
flood warning system
model of US economy
model of a heat reservoir
map
12

7. A Message to Map Makers
A model is a means of communication
Users of a model must have a certain amount of
knowledge in common
A model on emphasized selected aspects
A model is described in some language
A model can be erroneous
A message to map makers: “Highways are not
painted red, rivers don’t have county lines running
down the middle, and you can’t see contour lines on
a mountain” [Kent 78]
13
Use a DBMS when
this is important
persistent storage of data
centralized control of data
control of redundancy
control of consistency and
integrity
multiple user support
sharing of data
data documentation
data independence
control of access and
security
backup and recovery
Do not use a
DBMS when
l the initial investment in
hardware, software, and
training is too high
l the generality a DBMS
provides is not needed
l the overhead for security,
concurrency control, and
recovery is too high
l data and applications are
simple and stable
l real-time requirements
cannot be met by it
l multiple user access is not
needed
14

8. Data Modeling
REALITY
• structures
• processes
DATABASE SYSTEM
MODELdata modeling
l The model represents a perception of structures of
reality
l The data modeling process is to fix a perception of
structures of reality and represent this perception
l In the data modeling process we select aspects and
we abstract
15
Process Modeling
REALITY
• structures
• processes
DATABASE SYSTEM
MODELprocess modeling
l The use of the model reflects processes of reality
l Processes may be represented by programs with
embedded database queries and updates
l Processes may be represented by ad-hoc database
queries and updates at run-time
DML DML
PROG
16

9. Database Design
is a model of structures of reality
supports queries and updates
modeling processes of reality
runs efficiently
The purpose of database design is to create a database
which
17
Database Capabilities
Data Storage
Queries
Optimization
Indexing
Concurrency Control
Recovery
Security
18

10. Data Storage
Disk management
File management
Buffer management
Garbage collection
Compression
19
Queries
Selection
Point
Range
Conjunction
Disjunction
Join
Natural join
Equi join
Theta join
Outer join
Projection
Set operations
Cartesian Product
Union
Intersection
Set Difference
Other
Duplicate elimination
Sorting
Built-in functions:
count, sum, avg, min,
max
Recursive (not in SQL)
SQL queries are composed from the following:
20

11. People that Work With Databases
System Analysts
Database Designers
Application Developers
Database Administrators
End Users
21
System Analysts
Communicate with each prospective database
user group in order to understand its
information needs
processing needs
Develop a specification of each user group’s
information and processing needs
Develop a specification integrating the
information and processing needs of the user
groups
Document the specification
22

12. Database Designers
Choose appropriate structures to
represent the information specified by the
system analysts
Choose appropriate structures to store the
information in a normalized manner in
order to guarantee integrity and
consistency of data
Choose appropriate structures to
guarantee an efficient system
Document the database design
23
Application Developers
Implement the database design
Implement the application programs to
meet the program specifications
Test and debug the database
implementation and the application
programs
Document the database implementation
and the application programs
24

13. Database Administrators
Manage the database structure
participate in database and application development
assist in requirement analysis
participate in database design and creation
develop procedures for integrity and quality of data
facilitate changes to database structure
seek communitywide solutions
assess impact on all users
provide configuration control
be prepared for problems after changes are made
maintain documentation
25
Database Administrators (cont.)
Manage data activity
establish database standards consistent with
data administration standards
establish and maintain data dictionary
establish data proponencies
work with data proponents to develop data
access and modification rights
develop, document, and train staff on backup
and recovery procedures
publish and maintain data activity standards
documentation
26

14. Database Administrators (cont.)
Manage the database management system
generate database application performance reports
investigate user performance complaints
assess need for changes in database structure or
application design
modify database structure
evaluate and implement new DBMS features
tune the database
Establish the database data dictionary
data names, formats, relationships
cross-references between data and application
programs
(see metadata slide)
27
End Users
Parametric end users constantly query and update
the database.
They use canned transactions to support standard queries
and updates.
Casual end users occasional access the database,
but may need different information each time.
They use sophisticated query languages and browsers.
Sophisticated end users have complex
requirement and need different information each
time.
They are thoroughly familiar with the capabilities of the
DBMS.
28

15. 29
References
Jeffrey A. Hoffer, et al: Modern Database Management,
8th Edition, 2007, Prentice Hall