Chapter 01 Fundamental of Database Management System (DBMS)

Fundamental of Database System
Chapter One:
Introduction to Database System
PreparedBy:-Mr.AbdurehmanM.(MSC.)
Gmail:-abdure288@gmail.com
Mettu University
Mr. Abdurehman M. , MeU 1

Contents of the Chapter
Mr. Abdurehman M. MeU 2
❖ Introduction of Database system
❖ Data management approaches
❖ DBMS and Components of DBMS
❖ Database development life cycles
❖ Users of the database system (DBA,
DBD & user )
❖ The ANSI-SPARC Architecture
❖ Database Languages (DDL, DML,DCL)

Terminologies of Database
System
❖ Data
➢ Data is a collection of raw facts, figures& events but has no
meaning for making decisions
➢ Data can be number, Characters, Symbols, pictures, sounds
etc..
➢ Types of data: Numeric data, Alphabetic data and
Alphanumeric data
❖ Information
➢ Processed data is called information
➢ Data is used as input for the processing and information is
output for the processing.
➢ It is more meaningful than data and is used for making
decisions.

Terminologies of Database System..
❖ Database
➢ Database is an organized collection of logically related
data.
❖ Database Management System(DBMS)
➢ The DBMS is a general-purpose software system/program
package that facilitates the processes of Defining,
Constructing, Manipulating, and Sharing databases among
various users and applications.
❖ Database system
➢ Is the combination of database management system
(DBMS) software , Database and other applications .

Database System Environment….

Data management
approaches
1. Manual approaches
➢ Before the advent of computerized file handling systems, a
manual method of file handling system which is dependent
on the use of file cabinets, drawers, pens, paper and pencil
were used.
➢ The data storage and retrieval will be performed using
human labor.
➢ The limitation of the manual file handling system includes:
✓ Prone to error
✓ Less secured
✓ Not sharable
✓ Difficultto update, retrieve, integrate
✓ You have the data but it is difficultto compile the
information

Data management
approaches…
2. Traditional file Based approaches
➢ File based systems were an early attempt to computerize
the manual filing system
➢ This approach is the decentralized computerized data
handling method.
➢ A collection of application programs perform services for
the end-users based on their own data separately.
➢ Such systems have number of programs for each of the
different applications in the organization. So, subjected to
serious data duplication problem.
➢ File, in traditional file based approach, is a collection of
records which containslogically related data.

Data management
approaches
Traditional file Based approaches view

Limitation of File Based Approach
➢ Redundancy or duplication of data
➢ Data inconsistency
➢ Difficult data Isolation
➢ Integrity Problems
➢ Security Problems/No authorized and
authentication facilities
➢ Data dependency on the application or file
➢ Limited data sharing
➢ Lengthy development and maintenance time
➢ Incompatible file formats between different
applications and programs.

3. Database approaches
➢ To become more effective computerized record keeping
system, a new approach was required by the name
database approach.
➢ This approach is the centralized computerized data
handling method.
➢ Database is a collection of logically related data where
these logically related data comprises entities, attributes,
relationships, and constraints or business rules of an
organization's information
➢ In addition to containing data required by an organization,
database also contains a description of the data which
called as “Metadata” or “Data Dictionary” or “Systems
Catalogue” or “Data about Data” or

3. Database approaches ….
➢ The purpose of database is to:-
▪ Store information and
▪ To allow users to retrieve and update that information
on demand.
➢ Each database application will perform the combination of:
▪ Creating database
▪ Reading
▪ Updating and Deleting data.
➢ Unlike the traditional file based approach in database
approach there is program data independence.
➢ Database is designed once and used simultaneously by
many users.

3. Database approaches ….

Benefit of Database
approach
➢ Data can be shared: two or more users can access and
use same data instead of storing data in redundant
manner for each user.
➢ Improved accessibility of data: by using structured
query languages, the users can easily access data
without programming experience.
➢ Redundancy can be reduced: isolated data is integrated
in database to decrease the redundant data stored at
different applications.
➢ Inconsistency can be avoided: controlled data
redundancy will avoid inconsistency of the data in the
database to some extent.

Benefit of Database
approach…
➢ Integrity can be maintained: data at different applications
will be integrated together with additional constraints to
facilitate shared data resource.
➢ Security measures can be enforced: the shared data can
be secured by having different levels of clearance and
other data security mechanisms.
➢ Centralized information control: it can be controlled and
managed at the central level
❖ Some common application area of Database system
➢ University , Bank
➢ Airline , Human resources
➢ Library , Sales
➢ Credit and transaction

Limitations and risk of Database Approach
➢ Introduction of new professional and
specialized personnel.
➢ Complexity in designing and managing data
➢ High cost to be incurred to develop and maintain
the system
➢ Complex backup and recovery services from the
users perspective
➢ Reduced performance due to centralization and
data independence
➢ High impact on the system when failure occurs
to the central system.

DBMS and Components
DBMS is a general-purpose software system that
facilitates the processes of
➢ Defining database :-involves specifying the structures, data types
and constraints of the data to be stored in the data-base.
➢ The database definition or descriptive information is also stored
by the DBMS in the form of a database catalog or dictionary; it is
called meta-data.
➢ Constructing the database is the process of storing the data on
some storage medium that is controlled by the DBMS.
➢ Manipulating a database includes functions such as retrieving
and updating specific data from database and generating reports
from the data.
➢ Sharing a database allows multiple users and programs to access
the database simultaneously

A Various Common of DBMS
❖ Server DBMS
❖Oracle
❖ SQL Server
❖DB2
❖MySQL, Firebird, PostgreSQL (Significant
open source DBMSs)
❖ Desktop DBMS
➢ Microsoft Access
➢ FoxPro, Paradox, Approach, FileMaker Pro

Database development life
cycles
As it is one component in most information system
development tasks, there are several steps in designing a
database system.
1. Planning: that is identifying information gap in an
organization and propose a database solution to solve
the problem.
2. Analysis: that concentrates more on fact finding about
the problem or the opportunity. Feasibility analysis,
requirement determination and structuring, and
selection of best design method are also performed at
this phase.

cycles…
3. Design: in database designing more emphasis is given
to this phase. The phase is further divided into three sub-
phases.
A. Conceptual Design: concise description of the data,
data type, relationship between data and constraints
on the data. There is no implementation or physical
detail consideration. Used to elicit and structure all
information requirements
B. Logical Design: a higher level conceptual abstraction
with selected specific data model to implement the
data structure. It is particular DBMS independent and
with no other physical considerations.

cycles…
C. Physical Design: physical implementation of the lower
level design of the database with respect to internal
storage and file structure of the database for the selected
DBMS.
• To develop all technology and organizational
specification.
4. Implementation: the testing and deployment of the
designed database for use.
5. Operation and Support: administering and maintaining
the operation of the database system and providing
support to users.

Users of the database system
Users of data bases system may be divided into:
➢ Those who actually use and control the content (called
“Actors on the Scene”) and
➢ Those who enable the database to be developed and
the DBMS software to be designed and implemented
(called “Workers Behind the Scene”).
1) Database administrators: responsible for authorizing
access to the database, for co-ordinating and
monitoring its use, acquiring software, and hardware
resources, controlling its use and monitoring efficiency
of operations

Users of the database system…
2) Database Designers: responsible to define the
content, the structure, the constraints, and functions
or transactions against the database. They must
communicate with the end-users and understand
their needs.
3. Application developer: are software programmers
that designs and implements the application
programs to be used as an interface for the database
system and for manipulating the data in the
database.

Users of the database system…
4) End-users: they use the data for , reports and some of them actually
update the database content
▪ Casual : access database occasionally when needed
▪ Naïve or Parametric: they make up a large section of the end-user
population. They use previously well-defined functions in the form
of “canned transactions” against the database. Examples are bank-
tellers or reservation clerks who do this activity for an entire shift of
operations.
▪ Sophisticated : these include business analysts, scientists,
engineers, others thoroughly familiar with the system capabilities.
Many use tools in the form of software packages that work closely
with the stored database.
▪Stand-alone : mostly maintain personal databases using ready-to-
use packaged applications.An example is a tax program user that
creates his or her own internal database.

The ANSI-SPARC Architecture
❖The major purpose of a database system is to provide
users with an abstract view of the system which some
time referred as architecture of the system
❖The main purpose is:
▪ To hide the complicity from the database users (
how to design and store) and
▪ To enable data independence among
development phases
❖There are three schema/levels of abstraction of the
database architecture:
➢ External/View level
➢ Logical or Conceptual level
➢ Physical/ internal level

The ANSI-SPARC Architecture of DB
❖External Level: Users' view of the database. Describes
that part of database that is relevant to a particular
user. Different users have their own customized view
of the database independent of other users.
❖Conceptual Level: Community view of the database.
Describes what data is stored in database and
relationships among the data.
❖Internal Level: Physical representation of the
database on the computer. Describes how the data is
stored in the database.

Three-level ANSI-SPARC Architecture of a Database
❖ Mappings among schema levels are needed to transform
requestsand data.
❖ Programs refer to an external schema, and are mapped by the
DBMS to the internal schema for execution.

Differences between Three Levels of ANSI-SPARC Architecture

Database Languages (DDL,
DML,DCL)
❖ SQL (Structured Query Language) is the most widely
used non-procedural language query language to
communicates with Relational Database.
❖ Can be divided into more specific language
I) Database Definition language (DDL)
DDL is Used to define the database structure or schema
• CREATE - to create objects in the database
• ALTER - alters the structure of the database
• DROP - delete objects from the database
• TRUNCATE - remove all records from a table
• COMMENT - add comments to the data dictionary
• RENAME - rename an object

Database Languages (DDL, DML,DCL)
II) Database Manipulation language(DML)
DML is a language that enables users to access or
manipulate data from database
• SELECT - retrieve data from the a database
• INSERT - insert data into a table
• UPDATE - updates existing data within a table
• DELETE - deletes all records from a table
III) Database Control language(DCL)
DCL is used to define roles and permissions to access
database
• GRANT - gives user's access privileges to database
• REVOKE - withdraw access privileges given with the GRANT

Review Questions
❖ Differences between data, database, information and metadata
❖ What are the disadvantagesof file processing?
❖ What is the database approach?
❖ What are the advantagesof the database approach?
❖ What are the costs and risks of the database approach?
❖ What are the componentsof the database environment?
❖ What are the database development life cycle?
❖ What are the users (actors and workers) and their roles in DB?
❖ What are The three-level Architecture of database)
❖ What are the databaseLanguages?

Chapter 01 Fundamental of Database Management System (DBMS)

More Related Content

What's hot (20)

Similar to Chapter 01 Fundamental of Database Management System (DBMS) (20)

Recently uploaded (20)

Chapter 01 Fundamental of Database Management System (DBMS)