Relational Database Managements Systems (Basic) | Information Technology for Class 10 PDF Download

 Page 1


 
 
SESSION 1: APPRECIATE CONCEPT OF DATABASE 
MANAGEMENT SYSTEM 
 
Relevant Knowledge 
A database is an organized collection of data. You can visualize it as a container of 
information. 
The data is typically organized to model relevant aspects of reality (for example, the 
availability of rooms in hotels), in a way that supports processes requiring this information 
(for example, finding a hotel with facilities such as Laundry, GYM etc…). 
 
Suppose if you own a stationary shop, you need to keep detailed records of the materials 
available in your shop. You also need to store information about pricing, stock levels for 
reordering, old stocks, etc. While in the manual system, you would maintain several files 
with different bits of information; in the computerized system you would use database 
programs such as Microsoft Access, OpenOffice.org Base, and MySQL, to organize the 
data as per your business need. 
The database concept has evolved since the 1960s to ease increasing difficulties in 
designing, building, and maintaining complex information systems (typically with many 
concurrent end-users, and with a large amount of diverse data).  
In this lesson, you will learn database concepts and to work with a Database Management 
System (DBMS). 
 
Database Management System 
 
A database management system is a software package with computer programs that 
controls the creation, maintenance, and use of a database. It allows organizations to 
conveniently develop databases for various applications. A database is an integrated 
collection of data records, files, and other objects. A DBMS allows different user 
application programs to concurrently access the same database. 
Well known DBMSs include Oracle, IBM DB2, Microsoft SQL Server, Microsoft 
Access, PostgreSQL, MySQL, FoxPro, and SQLite. 
 
Data can be organized into two types: 
• Flat File: Data is stored in a single table. Usually suitable for less amount of data. 
• Relational:  Data is stored in multiple tables and the tables are linked using a common 
field. Relational is suitable for medium to large amount of data. 
Page 2


 
 
SESSION 1: APPRECIATE CONCEPT OF DATABASE 
MANAGEMENT SYSTEM 
 
Relevant Knowledge 
A database is an organized collection of data. You can visualize it as a container of 
information. 
The data is typically organized to model relevant aspects of reality (for example, the 
availability of rooms in hotels), in a way that supports processes requiring this information 
(for example, finding a hotel with facilities such as Laundry, GYM etc…). 
 
Suppose if you own a stationary shop, you need to keep detailed records of the materials 
available in your shop. You also need to store information about pricing, stock levels for 
reordering, old stocks, etc. While in the manual system, you would maintain several files 
with different bits of information; in the computerized system you would use database 
programs such as Microsoft Access, OpenOffice.org Base, and MySQL, to organize the 
data as per your business need. 
The database concept has evolved since the 1960s to ease increasing difficulties in 
designing, building, and maintaining complex information systems (typically with many 
concurrent end-users, and with a large amount of diverse data).  
In this lesson, you will learn database concepts and to work with a Database Management 
System (DBMS). 
 
Database Management System 
 
A database management system is a software package with computer programs that 
controls the creation, maintenance, and use of a database. It allows organizations to 
conveniently develop databases for various applications. A database is an integrated 
collection of data records, files, and other objects. A DBMS allows different user 
application programs to concurrently access the same database. 
Well known DBMSs include Oracle, IBM DB2, Microsoft SQL Server, Microsoft 
Access, PostgreSQL, MySQL, FoxPro, and SQLite. 
 
Data can be organized into two types: 
• Flat File: Data is stored in a single table. Usually suitable for less amount of data. 
• Relational:  Data is stored in multiple tables and the tables are linked using a common 
field. Relational is suitable for medium to large amount of data. 
 
 
 
Database Servers 
Database servers are dedicated computers that hold the actual databases and run only the 
DBMS and related software. Typically databases available on the database servers are 
accessed through command line or graphic user interface tools referred to as Frontends; 
database servers are referred to as Back-ends. Such type of data access is referred to as a 
client-server model. 
 
Advantages of Database 
 
? Reduces Data Redundancy 
The database management systems contain multiple files that are to be stored in many 
different locations in a system or even across multiple systems. Because of this, there 
were sometimes multiple copies of the same file which lead to data redundancy.  
This is prevented in a database as there is a single database and any change in it is reflected 
immediately. Because of this, there is no chance of encountering duplicate data. 
? Sharing of Data 
In a database, the users of the database can share the data among themselves. There are 
various levels of authorisation to access the data, and consequently the data can only be 
shared based with the authorized users. 
Many remote users can also access the database simultaneously and share the data 
between themselves. 
? Data Integrity 
Data integrity means that the data is accurate and consistent in the database. Data Integrity 
is very important as there are multiple databases in a DBMS. All of these databases 
contain data that is visible to multiple users. So it is necessary to ensure that the data is 
correct and consistent in all the databases and for all the users.  
? Data Security 
Data Security is an important concept in a database. Only authorised users should be 
allowed to access the database and their identity should be authenticated using a username 
and password. Unauthorised users should not be allowed to access the database under any 
circumstances as it violates the integrity constraints. 
Page 3


 
 
SESSION 1: APPRECIATE CONCEPT OF DATABASE 
MANAGEMENT SYSTEM 
 
Relevant Knowledge 
A database is an organized collection of data. You can visualize it as a container of 
information. 
The data is typically organized to model relevant aspects of reality (for example, the 
availability of rooms in hotels), in a way that supports processes requiring this information 
(for example, finding a hotel with facilities such as Laundry, GYM etc…). 
 
Suppose if you own a stationary shop, you need to keep detailed records of the materials 
available in your shop. You also need to store information about pricing, stock levels for 
reordering, old stocks, etc. While in the manual system, you would maintain several files 
with different bits of information; in the computerized system you would use database 
programs such as Microsoft Access, OpenOffice.org Base, and MySQL, to organize the 
data as per your business need. 
The database concept has evolved since the 1960s to ease increasing difficulties in 
designing, building, and maintaining complex information systems (typically with many 
concurrent end-users, and with a large amount of diverse data).  
In this lesson, you will learn database concepts and to work with a Database Management 
System (DBMS). 
 
Database Management System 
 
A database management system is a software package with computer programs that 
controls the creation, maintenance, and use of a database. It allows organizations to 
conveniently develop databases for various applications. A database is an integrated 
collection of data records, files, and other objects. A DBMS allows different user 
application programs to concurrently access the same database. 
Well known DBMSs include Oracle, IBM DB2, Microsoft SQL Server, Microsoft 
Access, PostgreSQL, MySQL, FoxPro, and SQLite. 
 
Data can be organized into two types: 
• Flat File: Data is stored in a single table. Usually suitable for less amount of data. 
• Relational:  Data is stored in multiple tables and the tables are linked using a common 
field. Relational is suitable for medium to large amount of data. 
 
 
 
Database Servers 
Database servers are dedicated computers that hold the actual databases and run only the 
DBMS and related software. Typically databases available on the database servers are 
accessed through command line or graphic user interface tools referred to as Frontends; 
database servers are referred to as Back-ends. Such type of data access is referred to as a 
client-server model. 
 
Advantages of Database 
 
? Reduces Data Redundancy 
The database management systems contain multiple files that are to be stored in many 
different locations in a system or even across multiple systems. Because of this, there 
were sometimes multiple copies of the same file which lead to data redundancy.  
This is prevented in a database as there is a single database and any change in it is reflected 
immediately. Because of this, there is no chance of encountering duplicate data. 
? Sharing of Data 
In a database, the users of the database can share the data among themselves. There are 
various levels of authorisation to access the data, and consequently the data can only be 
shared based with the authorized users. 
Many remote users can also access the database simultaneously and share the data 
between themselves. 
? Data Integrity 
Data integrity means that the data is accurate and consistent in the database. Data Integrity 
is very important as there are multiple databases in a DBMS. All of these databases 
contain data that is visible to multiple users. So it is necessary to ensure that the data is 
correct and consistent in all the databases and for all the users.  
? Data Security 
Data Security is an important concept in a database. Only authorised users should be 
allowed to access the database and their identity should be authenticated using a username 
and password. Unauthorised users should not be allowed to access the database under any 
circumstances as it violates the integrity constraints. 
 
 
? Privacy 
 
The privacy rule in a database states that only the authorized users can access a database 
according to its privacy constraints. To secure data levels are set in the database and a 
user can only view the data which is allowed to be seen. For example - In social 
networking sites, access constraints are different for different accounts a user may want 
to access. 
? Backup and Recovery 
Database Management System automatically takes care of backup and recovery. The 
users don't need to backup data periodically because this is taken care of by the DBMS. 
Moreover, it also restores the database after a crash or system failure to its previous 
condition.  
? Data Consistency 
Data consistency is ensured in a database because there is no data redundancy. Data 
Consistency means there should be multiple mismatching copies of the same data. All 
data appears consistently across the database and must be same for all the users viewing 
the database. Moreover, any changes made to the database are immediately reflected to 
all the users and there is no data inconsistency. 
 
Features of Database 
 
Let’s look at the example of your address book. What do you store in an address book? 
You may have people’s name, address, phone number and maybe even their birthdays. 
There is a common element here – people. In this example, each person is considered an 
“ITEM”.  
So, database will store information about that person. When you were recording 
information in your address book, what did you ask the people? What is your address? 
What is your phone number? etc. Each question that we ask about our ITEM is a “field”. 
Now, say you make new friends and want to add their information to your address book. 
You will ask questions, get the answers and create a new “record”. So, a record is a set 
of information (made up of fields) stored in your database about one of the items. A 
“value” is the actual text or numerical amount or date that you put in while adding 
Page 4


 
 
SESSION 1: APPRECIATE CONCEPT OF DATABASE 
MANAGEMENT SYSTEM 
 
Relevant Knowledge 
A database is an organized collection of data. You can visualize it as a container of 
information. 
The data is typically organized to model relevant aspects of reality (for example, the 
availability of rooms in hotels), in a way that supports processes requiring this information 
(for example, finding a hotel with facilities such as Laundry, GYM etc…). 
 
Suppose if you own a stationary shop, you need to keep detailed records of the materials 
available in your shop. You also need to store information about pricing, stock levels for 
reordering, old stocks, etc. While in the manual system, you would maintain several files 
with different bits of information; in the computerized system you would use database 
programs such as Microsoft Access, OpenOffice.org Base, and MySQL, to organize the 
data as per your business need. 
The database concept has evolved since the 1960s to ease increasing difficulties in 
designing, building, and maintaining complex information systems (typically with many 
concurrent end-users, and with a large amount of diverse data).  
In this lesson, you will learn database concepts and to work with a Database Management 
System (DBMS). 
 
Database Management System 
 
A database management system is a software package with computer programs that 
controls the creation, maintenance, and use of a database. It allows organizations to 
conveniently develop databases for various applications. A database is an integrated 
collection of data records, files, and other objects. A DBMS allows different user 
application programs to concurrently access the same database. 
Well known DBMSs include Oracle, IBM DB2, Microsoft SQL Server, Microsoft 
Access, PostgreSQL, MySQL, FoxPro, and SQLite. 
 
Data can be organized into two types: 
• Flat File: Data is stored in a single table. Usually suitable for less amount of data. 
• Relational:  Data is stored in multiple tables and the tables are linked using a common 
field. Relational is suitable for medium to large amount of data. 
 
 
 
Database Servers 
Database servers are dedicated computers that hold the actual databases and run only the 
DBMS and related software. Typically databases available on the database servers are 
accessed through command line or graphic user interface tools referred to as Frontends; 
database servers are referred to as Back-ends. Such type of data access is referred to as a 
client-server model. 
 
Advantages of Database 
 
? Reduces Data Redundancy 
The database management systems contain multiple files that are to be stored in many 
different locations in a system or even across multiple systems. Because of this, there 
were sometimes multiple copies of the same file which lead to data redundancy.  
This is prevented in a database as there is a single database and any change in it is reflected 
immediately. Because of this, there is no chance of encountering duplicate data. 
? Sharing of Data 
In a database, the users of the database can share the data among themselves. There are 
various levels of authorisation to access the data, and consequently the data can only be 
shared based with the authorized users. 
Many remote users can also access the database simultaneously and share the data 
between themselves. 
? Data Integrity 
Data integrity means that the data is accurate and consistent in the database. Data Integrity 
is very important as there are multiple databases in a DBMS. All of these databases 
contain data that is visible to multiple users. So it is necessary to ensure that the data is 
correct and consistent in all the databases and for all the users.  
? Data Security 
Data Security is an important concept in a database. Only authorised users should be 
allowed to access the database and their identity should be authenticated using a username 
and password. Unauthorised users should not be allowed to access the database under any 
circumstances as it violates the integrity constraints. 
 
 
? Privacy 
 
The privacy rule in a database states that only the authorized users can access a database 
according to its privacy constraints. To secure data levels are set in the database and a 
user can only view the data which is allowed to be seen. For example - In social 
networking sites, access constraints are different for different accounts a user may want 
to access. 
? Backup and Recovery 
Database Management System automatically takes care of backup and recovery. The 
users don't need to backup data periodically because this is taken care of by the DBMS. 
Moreover, it also restores the database after a crash or system failure to its previous 
condition.  
? Data Consistency 
Data consistency is ensured in a database because there is no data redundancy. Data 
Consistency means there should be multiple mismatching copies of the same data. All 
data appears consistently across the database and must be same for all the users viewing 
the database. Moreover, any changes made to the database are immediately reflected to 
all the users and there is no data inconsistency. 
 
Features of Database 
 
Let’s look at the example of your address book. What do you store in an address book? 
You may have people’s name, address, phone number and maybe even their birthdays. 
There is a common element here – people. In this example, each person is considered an 
“ITEM”.  
So, database will store information about that person. When you were recording 
information in your address book, what did you ask the people? What is your address? 
What is your phone number? etc. Each question that we ask about our ITEM is a “field”. 
Now, say you make new friends and want to add their information to your address book. 
You will ask questions, get the answers and create a new “record”. So, a record is a set 
of information (made up of fields) stored in your database about one of the items. A 
“value” is the actual text or numerical amount or date that you put in while adding 
 
 
information to your database. When you put all the information together in a grid (like 
you do in a spreadsheet), a collection of similar records creates a table. 
There are some key features of a database: 
1. A database can have one or many tables. An address book example is a very simple 
one, in real world there are many more details involved. A big company would have 
in its database, one table for its products, one table for its suppliers, one table for its 
customer details, one for orders received and maybe many others.  
2. Each table in a database contains information about one type of item. So, a database 
is a container that holds tables and other objects and manages how they can be used. 
3. Another very important thing to remember is that when we put in information, we may 
have people with the same name (there can be more than one Charu Arora) or the same 
address (members of a family). But when creating a database an important feature is 
record uniqueness in every table. it is important to be able to distinguish between 
different items having duplicate values. 
Uniqueness helps to avoid accidental duplication of records caused by user or 
computer error. This can be achieved by using some number or value that uniquely 
identifies a record. If such a unique value does not exist in your fields, as the database 
designer, you can create a special additional field in a table where unique numbers or 
values can be assigned for each new entry. Therefore, every table has a key field which 
ensures that there are 100% unique values throughout the database. 
4. Every database table should have one or more fields designated as key.   You can 
assign a unique value to this key for differentiating records that may have similar 
names or addresses. 
 
Look at the following example of student database: 
 
              
 
Page 5


 
 
SESSION 1: APPRECIATE CONCEPT OF DATABASE 
MANAGEMENT SYSTEM 
 
Relevant Knowledge 
A database is an organized collection of data. You can visualize it as a container of 
information. 
The data is typically organized to model relevant aspects of reality (for example, the 
availability of rooms in hotels), in a way that supports processes requiring this information 
(for example, finding a hotel with facilities such as Laundry, GYM etc…). 
 
Suppose if you own a stationary shop, you need to keep detailed records of the materials 
available in your shop. You also need to store information about pricing, stock levels for 
reordering, old stocks, etc. While in the manual system, you would maintain several files 
with different bits of information; in the computerized system you would use database 
programs such as Microsoft Access, OpenOffice.org Base, and MySQL, to organize the 
data as per your business need. 
The database concept has evolved since the 1960s to ease increasing difficulties in 
designing, building, and maintaining complex information systems (typically with many 
concurrent end-users, and with a large amount of diverse data).  
In this lesson, you will learn database concepts and to work with a Database Management 
System (DBMS). 
 
Database Management System 
 
A database management system is a software package with computer programs that 
controls the creation, maintenance, and use of a database. It allows organizations to 
conveniently develop databases for various applications. A database is an integrated 
collection of data records, files, and other objects. A DBMS allows different user 
application programs to concurrently access the same database. 
Well known DBMSs include Oracle, IBM DB2, Microsoft SQL Server, Microsoft 
Access, PostgreSQL, MySQL, FoxPro, and SQLite. 
 
Data can be organized into two types: 
• Flat File: Data is stored in a single table. Usually suitable for less amount of data. 
• Relational:  Data is stored in multiple tables and the tables are linked using a common 
field. Relational is suitable for medium to large amount of data. 
 
 
 
Database Servers 
Database servers are dedicated computers that hold the actual databases and run only the 
DBMS and related software. Typically databases available on the database servers are 
accessed through command line or graphic user interface tools referred to as Frontends; 
database servers are referred to as Back-ends. Such type of data access is referred to as a 
client-server model. 
 
Advantages of Database 
 
? Reduces Data Redundancy 
The database management systems contain multiple files that are to be stored in many 
different locations in a system or even across multiple systems. Because of this, there 
were sometimes multiple copies of the same file which lead to data redundancy.  
This is prevented in a database as there is a single database and any change in it is reflected 
immediately. Because of this, there is no chance of encountering duplicate data. 
? Sharing of Data 
In a database, the users of the database can share the data among themselves. There are 
various levels of authorisation to access the data, and consequently the data can only be 
shared based with the authorized users. 
Many remote users can also access the database simultaneously and share the data 
between themselves. 
? Data Integrity 
Data integrity means that the data is accurate and consistent in the database. Data Integrity 
is very important as there are multiple databases in a DBMS. All of these databases 
contain data that is visible to multiple users. So it is necessary to ensure that the data is 
correct and consistent in all the databases and for all the users.  
? Data Security 
Data Security is an important concept in a database. Only authorised users should be 
allowed to access the database and their identity should be authenticated using a username 
and password. Unauthorised users should not be allowed to access the database under any 
circumstances as it violates the integrity constraints. 
 
 
? Privacy 
 
The privacy rule in a database states that only the authorized users can access a database 
according to its privacy constraints. To secure data levels are set in the database and a 
user can only view the data which is allowed to be seen. For example - In social 
networking sites, access constraints are different for different accounts a user may want 
to access. 
? Backup and Recovery 
Database Management System automatically takes care of backup and recovery. The 
users don't need to backup data periodically because this is taken care of by the DBMS. 
Moreover, it also restores the database after a crash or system failure to its previous 
condition.  
? Data Consistency 
Data consistency is ensured in a database because there is no data redundancy. Data 
Consistency means there should be multiple mismatching copies of the same data. All 
data appears consistently across the database and must be same for all the users viewing 
the database. Moreover, any changes made to the database are immediately reflected to 
all the users and there is no data inconsistency. 
 
Features of Database 
 
Let’s look at the example of your address book. What do you store in an address book? 
You may have people’s name, address, phone number and maybe even their birthdays. 
There is a common element here – people. In this example, each person is considered an 
“ITEM”.  
So, database will store information about that person. When you were recording 
information in your address book, what did you ask the people? What is your address? 
What is your phone number? etc. Each question that we ask about our ITEM is a “field”. 
Now, say you make new friends and want to add their information to your address book. 
You will ask questions, get the answers and create a new “record”. So, a record is a set 
of information (made up of fields) stored in your database about one of the items. A 
“value” is the actual text or numerical amount or date that you put in while adding 
 
 
information to your database. When you put all the information together in a grid (like 
you do in a spreadsheet), a collection of similar records creates a table. 
There are some key features of a database: 
1. A database can have one or many tables. An address book example is a very simple 
one, in real world there are many more details involved. A big company would have 
in its database, one table for its products, one table for its suppliers, one table for its 
customer details, one for orders received and maybe many others.  
2. Each table in a database contains information about one type of item. So, a database 
is a container that holds tables and other objects and manages how they can be used. 
3. Another very important thing to remember is that when we put in information, we may 
have people with the same name (there can be more than one Charu Arora) or the same 
address (members of a family). But when creating a database an important feature is 
record uniqueness in every table. it is important to be able to distinguish between 
different items having duplicate values. 
Uniqueness helps to avoid accidental duplication of records caused by user or 
computer error. This can be achieved by using some number or value that uniquely 
identifies a record. If such a unique value does not exist in your fields, as the database 
designer, you can create a special additional field in a table where unique numbers or 
values can be assigned for each new entry. Therefore, every table has a key field which 
ensures that there are 100% unique values throughout the database. 
4. Every database table should have one or more fields designated as key.   You can 
assign a unique value to this key for differentiating records that may have similar 
names or addresses. 
 
Look at the following example of student database: 
 
              
 
 
 
In this table, it will be extremely difficult to differentiate between student records as they 
have names that are similar. To differentiate, you can add additional field - roll number - 
that will be unique for each record (example below). 
 
 
 
 
EXAMPLE OF RDBMS 
 
You had used the example of an address book in the previous section. An address book 
uses only one table. But look at a different situation. If you are a dealer selling a single 
type of item and want to record details of your sales in the past month and also want the 
details of the client who purchased the item ( name, address, phone, date purchased, 
number of items bought etc), what would you do?.  
You create a table Sales with all the details: 
 
 
Do you see a problem here? Every time you sell an item to Sheela or Vaibhav or any other 
customer (client) you need to store the details again. So, what is the solution? Create one 
table for client details and another for sale details. Since each record has to be unique, 
you can insert a ClientID field to uniquely identify each client in the client table. In the 
Sales table, you would give a point of reference which “points” to a particular record in 
the Client table.