SlideShare ist ein Scribd-Unternehmen logo
1 von 21
Downloaden Sie, um offline zu lesen
COMPONENTS AND ADVANTAGES OF DBMS
BY: SHUBHAM JOON
ASSIGNMENT 1
WHAT IS DBMS??!!
• A database-management system (DBMS) is a computer-software application that interacts
with end-users, other applications, and the database itself to capture and analyse data. A
general-purpose DBMS allows the definition, creation, querying, update, and administration of
databases. Well-known DBMSs include MySQL, PostgreSQL, MongoDB, MariaDB, Microsoft SQL
Server, Oracle, Sybase, SAP HANA, MemSQL, SQLite and IBM DB2.
FILE BASED SYSTEM V/S DBMS
COMPONENTS OF DBMS
A database management system (DBMS) consists of several components. Each component plays very
important role in the database management system environment. The major components of database
management system are:
• Software
• Hardware
• Data
• Procedures
• Users (or people)
1. SOFTWARE
• The main component of a DBMS is the software. It is the set of programs used to handle the database
and to control and manage the overall computerized database
• DBMS software itself, is the most important software component in the overall system
• Operating system including network software being used in network, to share the data of database
among multiple users.
• Application programs developed in programming languages such as C++, Visual Basic that are used to to
access database in database management system. Each program contains statements that request the
DBMS to perform operation on database. The operations may include retrieving, updating, deleting
data etc . The application program may be conventional or online workstations or terminals.
2. HARDWARE
Hardware consists of a set of physical electronic devices such as computers (together with associated I/O
devices like disk drives), storage devices, I/O channels, electromechanical devices that make interface
between computers and the real world systems etc, and so on. It is impossible to implement the DBMS
without the hardware devices, In a network, a powerful computer with high data processing speed and a
storage device with large storage capacity is required as database server.
3.DATA
Data is the most important component of the DBMS.
The main purpose of DBMS is to process the data. In DBMS,
databases are defined, constructed and then data is stored,
updated and retrieved to and from the databases. The database
contains both the actual (or operational) data and the metadata
(data about data or description about data).
4. PROCEDURES
• Procedures refer to the instructions and rules that help to design the database and to use the DBMS.
The users that operate and manage the DBMS require documented procedures on hot use or run the
database management system. These may include.
• Procedure to install the new DBMS.
• To log on to the DBMS.
• To use the DBMS or application program.
• To make backup copies of database.
• To change the structure of database.
• To generate the reports of data retrieved
• from database.
5. USERS (OR PEOPLE)
The users are the people who manage the databases and perform different operations on the databases in
the database system. There are three kinds of people who play different roles in database systems:-
1. Application Programmer
2. Database Administrators
3. End-Users
1. Naïve Users: These are the users who are constantly querying and updating the database. E.g. Bank
clerk, Railway clerk.
2. Casual Users: These are the people who use the database occasionally. E.g. ATM users.
3. Sophisticated Users: People who use for their complex requirements. E.g. Business and Financial
analyst.
4. Standalone Users: These are the users who maintain and use the database for their personal queries.
End Users:
Application Programmers
The people who write application programs in programming languages (such as Visual Basic, Java, or C++) to
interact with databases are called Application Programmer.
Database Administrators
A person who is responsible for managing the overall database management system is called database
administrator or simply DBA.
End-Users
The end-users are the people who interact with database management system to perform different
operations on database such as retrieving, updating, inserting, deleting data etc.
1. CONTROLLING DATA REDUNDANCY
In non-database systems (traditional computer file
processing), each application program has its own
files. In this case, the duplicated copies of the same
data are created at many places. In DBMS, all the
data of an organization is integrated into a single
database. The data is recorded at only one place in
the database and it is not duplicated.
For example, the General Office file and the account file contains several items that are identical. When they are
converted into database, the data is integrated into a single database so that multiple copies of the same data are
reduced to-single copy.
In DBMS, the data redundancy can be controlled or reduced but is not removed completely. Sometimes, it is
necessary to create duplicate copies of the same data items in order to relate tables with each other.
By controlling the data redundancy, you can save storage space. Similarly, it is useful for retrieving data from
database using queries.
2. DATA CONSISTENCY
By controlling the data redundancy, the data
consistency is obtained. If a data item appears
only once, any update to its value has to be
performed only once and the updated value
(new value of item) is immediately available to
all users.
If the DBMS has reduced redundancy to a
minimum level, the database system enforces
consistency. It means that when a data item
appears more than once in the database and is
updated, the DBMS automatically updates each
occurrence of a data item in the database.
3. DATA SHARING
In DBMS, data can be shared by authorized users
of the organization. The DBA manages the data
and gives rights to users to access the data. Many
users can be authorized to access the same set of
information simultaneously. The remote users can
also share same data. Similarly, the data of same
database can be shared between different
application programs.
4. DATA INTEGERATION
In DBMS, data in database is stored in tables.
A single database contains multiple tables
and relationships can be created between
tables (or associated data entities). This
makes easy to retrieve and update data.
5. INTEGRITY CONSTRAINTS
Integrity constraints or consistency rules can
be applied to database so that the correct
data can be entered into database. The
constraints may be applied to data item
within a single record or they may be applied
to relationships between records.
6. DATA SECURITY
It is the protection of the database from unauthorized users.
Only the authorized persons are allowed to access the database.
Some of the users may be allowed to access only a part of database
i.e., the data that is related to them or related to their department.
Mostly, the DBA or head of a department can access all the data in
the database. Some users may be permitted only to retrieve data,
whereas others are allowed to retrieve as well as to update data. The
database access is controlled by the DBA. He creates the accounts of
users and gives rights to access the database. Typically, users or group
of users are given usernames protected by passwords.
For example,
If you have an account of e-mail in the "hotmail.com" (a popular website),
then you have to give your correct username and password to access your
account of e-mail. Similarly, when you insert your ATM card into the Auto
Teller Machine (ATM) in a bank, the machine reads your ID number printed
on the card and then asks you to enter your pin code (or password).
In this way, you can access your account.
7. DATA ATOMICITY
A transaction in commercial databases is
referred to as atomic unit of work. For
example, when you purchase something
from a point of sale (POS) terminal, a
number of tasks are performed such as;
a) Company stock is updated.
b) Amount is added in company's account.
c) Sales person's commission increases etc.
All these tasks collectively are called an atomic
unit of work or transaction. These tasks must be
completed in all; otherwise partially completed
tasks are rolled back. Thus through DBMS, it is
ensured that only consistent data exists within
the database.
8. DATABASE ACCESS LANGUAGE
Most of the DBMSs provide SQL as standard database access
language. It is used to access data from multiple tables of a
database.
9. DEVELOPMENT OF APPLICATION
The cost and time for developing new applications is also
reduced. The DBMS provides tools that can be used to develop
application programs. For example, some wizards are available
to generate Forms and Reports. Stored procedures
(stored on server side) also reduce the size of application
programs.
10. CREATING FORMS
Form is very important object of DBMS. You can create Forms
very easily and quickly in DBMS, once a Form is created, it can
be used many times and it can be modified very easily. The
created Forms are also saved along with database and behave
like a software component. A Form provides very easy way
(user-friendly interface) to enter data into database, edit data, and display data from
database. The non-technical users can also perform various operations on databases
through Forms without going into the technical details of a database.
11. REPORT WRITERS
Most of the DBMSs provide the report writer tools used to create
reports. The users can create reports very easily and quickly.
Once a report is created, it can be used many times and it can be
modified very easily. The created reports are also saved along
with database and behave like a software component.
12. CONTROL OVER CONCURRENCY
In a computer file-based system, if two users are allowed to access
data simultaneously, it is possible that they will interfere with each
other. For example, if both users attempt to perform update
operation on the same record, then one may overwrite the values
recorded by the other. Most DBMSs have sub-systems to control the
concurrency so that transactions are always recorded" with
accuracy.
13. BACKUP AND RECOVERY PROCEDURES
In a computer file-based system, the user creates the backup of data regularly to
protect the valuable data from damaging due to failures to the computer system or
application program. It is a time consuming method, if volume of data is large. Most
of the DBMSs provide the 'backup and recovery' sub-systems that automatically
create the backup of data and restore data if required. For example, if the computer
system fails in the middle (or end) of an update operation of the program, the
recovery sub-system is responsible for making sure that the database is restored to
the state it was in before the program started executing.
14. DATA INDEPENDENCE
The separation of data structure of database from
the application program that is used to access data
from database is called data independence. In DBMS,
database and application programs are separated
from each other. The DBMS sits in between them.
You can easily change the structure of database
without modifying the application program. For
example you can modify the size or data type of a
data items (fields of a database table).
On the other hand, in computer file-based system,
the structure of data items are built into the
individual application programs. Thus the data is
dependent on the data file and vice versa.
ADVANCED CAPABILITIES OF DBMS
DBMS also provides advance capabilities for online access
and reporting of data through Internet. Today, most of the
database systems are online. The database technology is
used in conjunction with Internet technology to access data
on the web servers.
DBMS Components and Advantages

Weitere ähnliche Inhalte

Was ist angesagt?

Was ist angesagt? (20)

Types Of Keys in DBMS
Types Of Keys in DBMSTypes Of Keys in DBMS
Types Of Keys in DBMS
 
Dbms architecture
Dbms architectureDbms architecture
Dbms architecture
 
database language ppt.pptx
database language ppt.pptxdatabase language ppt.pptx
database language ppt.pptx
 
Distributed database
Distributed databaseDistributed database
Distributed database
 
File systems versus a dbms
File systems versus a dbmsFile systems versus a dbms
File systems versus a dbms
 
SQL(DDL & DML)
SQL(DDL & DML)SQL(DDL & DML)
SQL(DDL & DML)
 
Integrity Constraints
Integrity ConstraintsIntegrity Constraints
Integrity Constraints
 
Database Management System
Database Management SystemDatabase Management System
Database Management System
 
Database Design Slide 1
Database Design Slide 1Database Design Slide 1
Database Design Slide 1
 
Characteristic of dabase approach
Characteristic of dabase approachCharacteristic of dabase approach
Characteristic of dabase approach
 
SQL Views
SQL ViewsSQL Views
SQL Views
 
Database-Management-System-PPT.pptx
Database-Management-System-PPT.pptxDatabase-Management-System-PPT.pptx
Database-Management-System-PPT.pptx
 
Distributed database management system
Distributed database management  systemDistributed database management  system
Distributed database management system
 
Structure of dbms
Structure of dbmsStructure of dbms
Structure of dbms
 
Dbms and rdbms ppt
Dbms and rdbms pptDbms and rdbms ppt
Dbms and rdbms ppt
 
Database Presentation
Database PresentationDatabase Presentation
Database Presentation
 
Introduction to Database
Introduction to DatabaseIntroduction to Database
Introduction to Database
 
Data Base Management System
Data Base Management SystemData Base Management System
Data Base Management System
 
ER-Model-ER Diagram
ER-Model-ER DiagramER-Model-ER Diagram
ER-Model-ER Diagram
 
1.4 data independence
1.4 data independence1.4 data independence
1.4 data independence
 

Ähnlich wie DBMS Components and Advantages

Advantages of database management system
Advantages of database management system Advantages of database management system
Advantages of database management system Nafeesa Naeem
 
DBMS-INTRODUCTION.pptx
DBMS-INTRODUCTION.pptxDBMS-INTRODUCTION.pptx
DBMS-INTRODUCTION.pptxDivyaKS12
 
Chap1-Introduction to database systems.ppt
Chap1-Introduction to database systems.pptChap1-Introduction to database systems.ppt
Chap1-Introduction to database systems.pptLisaMalar
 
data base management report
data base management report data base management report
data base management report shivam tripathi
 
Cp 121 lecture 01
Cp 121 lecture 01Cp 121 lecture 01
Cp 121 lecture 01ITNet
 
We presented a list of capabilities that should be provided by the DB.pdf
We presented a list of capabilities that should be provided by the DB.pdfWe presented a list of capabilities that should be provided by the DB.pdf
We presented a list of capabilities that should be provided by the DB.pdfarchanacomputers1
 
Introduction to DBMS.pptx
Introduction to DBMS.pptxIntroduction to DBMS.pptx
Introduction to DBMS.pptxChandanHegde13
 
Database Management Systems (Mcom Ecommerce)
Database Management Systems (Mcom Ecommerce)Database Management Systems (Mcom Ecommerce)
Database Management Systems (Mcom Ecommerce)Rupen Parte
 
Dbms environment and components ppt.pptx
Dbms environment and components ppt.pptxDbms environment and components ppt.pptx
Dbms environment and components ppt.pptxRITIKRAJ437758
 
dbms Lesson for the Engineering students.pdf
dbms Lesson for the Engineering students.pdfdbms Lesson for the Engineering students.pdf
dbms Lesson for the Engineering students.pdfhpndegreecollegesklm
 

Ähnlich wie DBMS Components and Advantages (20)

Advantages of database management system
Advantages of database management system Advantages of database management system
Advantages of database management system
 
Database & dbms
Database & dbmsDatabase & dbms
Database & dbms
 
DBMS-INTRODUCTION.pptx
DBMS-INTRODUCTION.pptxDBMS-INTRODUCTION.pptx
DBMS-INTRODUCTION.pptx
 
Chap1-Introduction to database systems.ppt
Chap1-Introduction to database systems.pptChap1-Introduction to database systems.ppt
Chap1-Introduction to database systems.ppt
 
Dbms
DbmsDbms
Dbms
 
DBMS_UNIT_1.pdf
DBMS_UNIT_1.pdfDBMS_UNIT_1.pdf
DBMS_UNIT_1.pdf
 
data base management report
data base management report data base management report
data base management report
 
Database management system
Database management systemDatabase management system
Database management system
 
Assign 1
Assign 1Assign 1
Assign 1
 
Intro to dbms
Intro to dbmsIntro to dbms
Intro to dbms
 
Introduction DBMS.pptx
Introduction DBMS.pptxIntroduction DBMS.pptx
Introduction DBMS.pptx
 
Cp 121 lecture 01
Cp 121 lecture 01Cp 121 lecture 01
Cp 121 lecture 01
 
Unit1 dbms
Unit1 dbmsUnit1 dbms
Unit1 dbms
 
ms-11.pdf
ms-11.pdfms-11.pdf
ms-11.pdf
 
We presented a list of capabilities that should be provided by the DB.pdf
We presented a list of capabilities that should be provided by the DB.pdfWe presented a list of capabilities that should be provided by the DB.pdf
We presented a list of capabilities that should be provided by the DB.pdf
 
Introduction to DBMS.pptx
Introduction to DBMS.pptxIntroduction to DBMS.pptx
Introduction to DBMS.pptx
 
DBMS NOTES.pdf
DBMS  NOTES.pdfDBMS  NOTES.pdf
DBMS NOTES.pdf
 
Database Management Systems (Mcom Ecommerce)
Database Management Systems (Mcom Ecommerce)Database Management Systems (Mcom Ecommerce)
Database Management Systems (Mcom Ecommerce)
 
Dbms environment and components ppt.pptx
Dbms environment and components ppt.pptxDbms environment and components ppt.pptx
Dbms environment and components ppt.pptx
 
dbms Lesson for the Engineering students.pdf
dbms Lesson for the Engineering students.pdfdbms Lesson for the Engineering students.pdf
dbms Lesson for the Engineering students.pdf
 

Kürzlich hochgeladen

Digital Indonesia Report 2024 by We Are Social .pdf
Digital Indonesia Report 2024 by We Are Social .pdfDigital Indonesia Report 2024 by We Are Social .pdf
Digital Indonesia Report 2024 by We Are Social .pdfNicoChristianSunaryo
 
Data Analysis Project Presentation: Unveiling Your Ideal Customer, Bank Custo...
Data Analysis Project Presentation: Unveiling Your Ideal Customer, Bank Custo...Data Analysis Project Presentation: Unveiling Your Ideal Customer, Bank Custo...
Data Analysis Project Presentation: Unveiling Your Ideal Customer, Bank Custo...Boston Institute of Analytics
 
Statistics For Management by Richard I. Levin 8ed.pdf
Statistics For Management by Richard I. Levin 8ed.pdfStatistics For Management by Richard I. Levin 8ed.pdf
Statistics For Management by Richard I. Levin 8ed.pdfnikeshsingh56
 
DATA ANALYSIS using various data sets like shoping data set etc
DATA ANALYSIS using various data sets like shoping data set etcDATA ANALYSIS using various data sets like shoping data set etc
DATA ANALYSIS using various data sets like shoping data set etclalithasri22
 
Decoding Movie Sentiments: Analyzing Reviews with Data Analysis model
Decoding Movie Sentiments: Analyzing Reviews with Data Analysis modelDecoding Movie Sentiments: Analyzing Reviews with Data Analysis model
Decoding Movie Sentiments: Analyzing Reviews with Data Analysis modelBoston Institute of Analytics
 
English-8-Q4-W3-Synthesizing-Essential-Information-From-Various-Sources-1.pdf
English-8-Q4-W3-Synthesizing-Essential-Information-From-Various-Sources-1.pdfEnglish-8-Q4-W3-Synthesizing-Essential-Information-From-Various-Sources-1.pdf
English-8-Q4-W3-Synthesizing-Essential-Information-From-Various-Sources-1.pdfblazblazml
 
6 Tips for Interpretable Topic Models _ by Nicha Ruchirawat _ Towards Data Sc...
6 Tips for Interpretable Topic Models _ by Nicha Ruchirawat _ Towards Data Sc...6 Tips for Interpretable Topic Models _ by Nicha Ruchirawat _ Towards Data Sc...
6 Tips for Interpretable Topic Models _ by Nicha Ruchirawat _ Towards Data Sc...Dr Arash Najmaei ( Phd., MBA, BSc)
 
Digital Marketing Plan, how digital marketing works
Digital Marketing Plan, how digital marketing worksDigital Marketing Plan, how digital marketing works
Digital Marketing Plan, how digital marketing worksdeepakthakur548787
 
why-transparency-and-traceability-are-essential-for-sustainable-supply-chains...
why-transparency-and-traceability-are-essential-for-sustainable-supply-chains...why-transparency-and-traceability-are-essential-for-sustainable-supply-chains...
why-transparency-and-traceability-are-essential-for-sustainable-supply-chains...Jack Cole
 
Role of Consumer Insights in business transformation
Role of Consumer Insights in business transformationRole of Consumer Insights in business transformation
Role of Consumer Insights in business transformationAnnie Melnic
 
Bank Loan Approval Analysis: A Comprehensive Data Analysis Project
Bank Loan Approval Analysis: A Comprehensive Data Analysis ProjectBank Loan Approval Analysis: A Comprehensive Data Analysis Project
Bank Loan Approval Analysis: A Comprehensive Data Analysis ProjectBoston Institute of Analytics
 
Non Text Magic Studio Magic Design for Presentations L&P.pdf
Non Text Magic Studio Magic Design for Presentations L&P.pdfNon Text Magic Studio Magic Design for Presentations L&P.pdf
Non Text Magic Studio Magic Design for Presentations L&P.pdfPratikPatil591646
 
Presentation of project of business person who are success
Presentation of project of business person who are successPresentation of project of business person who are success
Presentation of project of business person who are successPratikSingh115843
 
IBEF report on the Insurance market in India
IBEF report on the Insurance market in IndiaIBEF report on the Insurance market in India
IBEF report on the Insurance market in IndiaManalVerma4
 

Kürzlich hochgeladen (17)

2023 Survey Shows Dip in High School E-Cigarette Use
2023 Survey Shows Dip in High School E-Cigarette Use2023 Survey Shows Dip in High School E-Cigarette Use
2023 Survey Shows Dip in High School E-Cigarette Use
 
Digital Indonesia Report 2024 by We Are Social .pdf
Digital Indonesia Report 2024 by We Are Social .pdfDigital Indonesia Report 2024 by We Are Social .pdf
Digital Indonesia Report 2024 by We Are Social .pdf
 
Data Analysis Project Presentation: Unveiling Your Ideal Customer, Bank Custo...
Data Analysis Project Presentation: Unveiling Your Ideal Customer, Bank Custo...Data Analysis Project Presentation: Unveiling Your Ideal Customer, Bank Custo...
Data Analysis Project Presentation: Unveiling Your Ideal Customer, Bank Custo...
 
Statistics For Management by Richard I. Levin 8ed.pdf
Statistics For Management by Richard I. Levin 8ed.pdfStatistics For Management by Richard I. Levin 8ed.pdf
Statistics For Management by Richard I. Levin 8ed.pdf
 
DATA ANALYSIS using various data sets like shoping data set etc
DATA ANALYSIS using various data sets like shoping data set etcDATA ANALYSIS using various data sets like shoping data set etc
DATA ANALYSIS using various data sets like shoping data set etc
 
Decoding Movie Sentiments: Analyzing Reviews with Data Analysis model
Decoding Movie Sentiments: Analyzing Reviews with Data Analysis modelDecoding Movie Sentiments: Analyzing Reviews with Data Analysis model
Decoding Movie Sentiments: Analyzing Reviews with Data Analysis model
 
English-8-Q4-W3-Synthesizing-Essential-Information-From-Various-Sources-1.pdf
English-8-Q4-W3-Synthesizing-Essential-Information-From-Various-Sources-1.pdfEnglish-8-Q4-W3-Synthesizing-Essential-Information-From-Various-Sources-1.pdf
English-8-Q4-W3-Synthesizing-Essential-Information-From-Various-Sources-1.pdf
 
6 Tips for Interpretable Topic Models _ by Nicha Ruchirawat _ Towards Data Sc...
6 Tips for Interpretable Topic Models _ by Nicha Ruchirawat _ Towards Data Sc...6 Tips for Interpretable Topic Models _ by Nicha Ruchirawat _ Towards Data Sc...
6 Tips for Interpretable Topic Models _ by Nicha Ruchirawat _ Towards Data Sc...
 
Digital Marketing Plan, how digital marketing works
Digital Marketing Plan, how digital marketing worksDigital Marketing Plan, how digital marketing works
Digital Marketing Plan, how digital marketing works
 
why-transparency-and-traceability-are-essential-for-sustainable-supply-chains...
why-transparency-and-traceability-are-essential-for-sustainable-supply-chains...why-transparency-and-traceability-are-essential-for-sustainable-supply-chains...
why-transparency-and-traceability-are-essential-for-sustainable-supply-chains...
 
Role of Consumer Insights in business transformation
Role of Consumer Insights in business transformationRole of Consumer Insights in business transformation
Role of Consumer Insights in business transformation
 
Bank Loan Approval Analysis: A Comprehensive Data Analysis Project
Bank Loan Approval Analysis: A Comprehensive Data Analysis ProjectBank Loan Approval Analysis: A Comprehensive Data Analysis Project
Bank Loan Approval Analysis: A Comprehensive Data Analysis Project
 
Non Text Magic Studio Magic Design for Presentations L&P.pdf
Non Text Magic Studio Magic Design for Presentations L&P.pdfNon Text Magic Studio Magic Design for Presentations L&P.pdf
Non Text Magic Studio Magic Design for Presentations L&P.pdf
 
Data Analysis Project: Stroke Prediction
Data Analysis Project: Stroke PredictionData Analysis Project: Stroke Prediction
Data Analysis Project: Stroke Prediction
 
Insurance Churn Prediction Data Analysis Project
Insurance Churn Prediction Data Analysis ProjectInsurance Churn Prediction Data Analysis Project
Insurance Churn Prediction Data Analysis Project
 
Presentation of project of business person who are success
Presentation of project of business person who are successPresentation of project of business person who are success
Presentation of project of business person who are success
 
IBEF report on the Insurance market in India
IBEF report on the Insurance market in IndiaIBEF report on the Insurance market in India
IBEF report on the Insurance market in India
 

DBMS Components and Advantages

  • 1. COMPONENTS AND ADVANTAGES OF DBMS BY: SHUBHAM JOON ASSIGNMENT 1
  • 2. WHAT IS DBMS??!! • A database-management system (DBMS) is a computer-software application that interacts with end-users, other applications, and the database itself to capture and analyse data. A general-purpose DBMS allows the definition, creation, querying, update, and administration of databases. Well-known DBMSs include MySQL, PostgreSQL, MongoDB, MariaDB, Microsoft SQL Server, Oracle, Sybase, SAP HANA, MemSQL, SQLite and IBM DB2.
  • 3. FILE BASED SYSTEM V/S DBMS
  • 4. COMPONENTS OF DBMS A database management system (DBMS) consists of several components. Each component plays very important role in the database management system environment. The major components of database management system are: • Software • Hardware • Data • Procedures • Users (or people)
  • 5. 1. SOFTWARE • The main component of a DBMS is the software. It is the set of programs used to handle the database and to control and manage the overall computerized database • DBMS software itself, is the most important software component in the overall system • Operating system including network software being used in network, to share the data of database among multiple users. • Application programs developed in programming languages such as C++, Visual Basic that are used to to access database in database management system. Each program contains statements that request the DBMS to perform operation on database. The operations may include retrieving, updating, deleting data etc . The application program may be conventional or online workstations or terminals.
  • 6. 2. HARDWARE Hardware consists of a set of physical electronic devices such as computers (together with associated I/O devices like disk drives), storage devices, I/O channels, electromechanical devices that make interface between computers and the real world systems etc, and so on. It is impossible to implement the DBMS without the hardware devices, In a network, a powerful computer with high data processing speed and a storage device with large storage capacity is required as database server.
  • 7. 3.DATA Data is the most important component of the DBMS. The main purpose of DBMS is to process the data. In DBMS, databases are defined, constructed and then data is stored, updated and retrieved to and from the databases. The database contains both the actual (or operational) data and the metadata (data about data or description about data).
  • 8. 4. PROCEDURES • Procedures refer to the instructions and rules that help to design the database and to use the DBMS. The users that operate and manage the DBMS require documented procedures on hot use or run the database management system. These may include. • Procedure to install the new DBMS. • To log on to the DBMS. • To use the DBMS or application program. • To make backup copies of database. • To change the structure of database. • To generate the reports of data retrieved • from database.
  • 9. 5. USERS (OR PEOPLE) The users are the people who manage the databases and perform different operations on the databases in the database system. There are three kinds of people who play different roles in database systems:- 1. Application Programmer 2. Database Administrators 3. End-Users
  • 10. 1. Naïve Users: These are the users who are constantly querying and updating the database. E.g. Bank clerk, Railway clerk. 2. Casual Users: These are the people who use the database occasionally. E.g. ATM users. 3. Sophisticated Users: People who use for their complex requirements. E.g. Business and Financial analyst. 4. Standalone Users: These are the users who maintain and use the database for their personal queries. End Users: Application Programmers The people who write application programs in programming languages (such as Visual Basic, Java, or C++) to interact with databases are called Application Programmer. Database Administrators A person who is responsible for managing the overall database management system is called database administrator or simply DBA. End-Users The end-users are the people who interact with database management system to perform different operations on database such as retrieving, updating, inserting, deleting data etc.
  • 11. 1. CONTROLLING DATA REDUNDANCY In non-database systems (traditional computer file processing), each application program has its own files. In this case, the duplicated copies of the same data are created at many places. In DBMS, all the data of an organization is integrated into a single database. The data is recorded at only one place in the database and it is not duplicated. For example, the General Office file and the account file contains several items that are identical. When they are converted into database, the data is integrated into a single database so that multiple copies of the same data are reduced to-single copy. In DBMS, the data redundancy can be controlled or reduced but is not removed completely. Sometimes, it is necessary to create duplicate copies of the same data items in order to relate tables with each other. By controlling the data redundancy, you can save storage space. Similarly, it is useful for retrieving data from database using queries.
  • 12. 2. DATA CONSISTENCY By controlling the data redundancy, the data consistency is obtained. If a data item appears only once, any update to its value has to be performed only once and the updated value (new value of item) is immediately available to all users. If the DBMS has reduced redundancy to a minimum level, the database system enforces consistency. It means that when a data item appears more than once in the database and is updated, the DBMS automatically updates each occurrence of a data item in the database.
  • 13. 3. DATA SHARING In DBMS, data can be shared by authorized users of the organization. The DBA manages the data and gives rights to users to access the data. Many users can be authorized to access the same set of information simultaneously. The remote users can also share same data. Similarly, the data of same database can be shared between different application programs.
  • 14. 4. DATA INTEGERATION In DBMS, data in database is stored in tables. A single database contains multiple tables and relationships can be created between tables (or associated data entities). This makes easy to retrieve and update data. 5. INTEGRITY CONSTRAINTS Integrity constraints or consistency rules can be applied to database so that the correct data can be entered into database. The constraints may be applied to data item within a single record or they may be applied to relationships between records.
  • 15. 6. DATA SECURITY It is the protection of the database from unauthorized users. Only the authorized persons are allowed to access the database. Some of the users may be allowed to access only a part of database i.e., the data that is related to them or related to their department. Mostly, the DBA or head of a department can access all the data in the database. Some users may be permitted only to retrieve data, whereas others are allowed to retrieve as well as to update data. The database access is controlled by the DBA. He creates the accounts of users and gives rights to access the database. Typically, users or group of users are given usernames protected by passwords. For example, If you have an account of e-mail in the "hotmail.com" (a popular website), then you have to give your correct username and password to access your account of e-mail. Similarly, when you insert your ATM card into the Auto Teller Machine (ATM) in a bank, the machine reads your ID number printed on the card and then asks you to enter your pin code (or password). In this way, you can access your account.
  • 16. 7. DATA ATOMICITY A transaction in commercial databases is referred to as atomic unit of work. For example, when you purchase something from a point of sale (POS) terminal, a number of tasks are performed such as; a) Company stock is updated. b) Amount is added in company's account. c) Sales person's commission increases etc. All these tasks collectively are called an atomic unit of work or transaction. These tasks must be completed in all; otherwise partially completed tasks are rolled back. Thus through DBMS, it is ensured that only consistent data exists within the database.
  • 17. 8. DATABASE ACCESS LANGUAGE Most of the DBMSs provide SQL as standard database access language. It is used to access data from multiple tables of a database. 9. DEVELOPMENT OF APPLICATION The cost and time for developing new applications is also reduced. The DBMS provides tools that can be used to develop application programs. For example, some wizards are available to generate Forms and Reports. Stored procedures (stored on server side) also reduce the size of application programs. 10. CREATING FORMS Form is very important object of DBMS. You can create Forms very easily and quickly in DBMS, once a Form is created, it can be used many times and it can be modified very easily. The created Forms are also saved along with database and behave like a software component. A Form provides very easy way (user-friendly interface) to enter data into database, edit data, and display data from database. The non-technical users can also perform various operations on databases through Forms without going into the technical details of a database.
  • 18. 11. REPORT WRITERS Most of the DBMSs provide the report writer tools used to create reports. The users can create reports very easily and quickly. Once a report is created, it can be used many times and it can be modified very easily. The created reports are also saved along with database and behave like a software component. 12. CONTROL OVER CONCURRENCY In a computer file-based system, if two users are allowed to access data simultaneously, it is possible that they will interfere with each other. For example, if both users attempt to perform update operation on the same record, then one may overwrite the values recorded by the other. Most DBMSs have sub-systems to control the concurrency so that transactions are always recorded" with accuracy.
  • 19. 13. BACKUP AND RECOVERY PROCEDURES In a computer file-based system, the user creates the backup of data regularly to protect the valuable data from damaging due to failures to the computer system or application program. It is a time consuming method, if volume of data is large. Most of the DBMSs provide the 'backup and recovery' sub-systems that automatically create the backup of data and restore data if required. For example, if the computer system fails in the middle (or end) of an update operation of the program, the recovery sub-system is responsible for making sure that the database is restored to the state it was in before the program started executing.
  • 20. 14. DATA INDEPENDENCE The separation of data structure of database from the application program that is used to access data from database is called data independence. In DBMS, database and application programs are separated from each other. The DBMS sits in between them. You can easily change the structure of database without modifying the application program. For example you can modify the size or data type of a data items (fields of a database table). On the other hand, in computer file-based system, the structure of data items are built into the individual application programs. Thus the data is dependent on the data file and vice versa. ADVANCED CAPABILITIES OF DBMS DBMS also provides advance capabilities for online access and reporting of data through Internet. Today, most of the database systems are online. The database technology is used in conjunction with Internet technology to access data on the web servers.