Database Management System And Components of Database Environment
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Database
The database is an organized collection of related data that is stored in an efficient and compact manner. The word organized means that data is stored in such a way that the user can use his data easily. The word relate means that a database is normally created to store the data about a particular topic.
For example, if a database is created for students, it will contain data about the students such as roll no, name address, etc. Similarly, if the database is about the employees of an organization, it will contain the data of employees ID, grade and salary, etc. All data in the database is arranged in tables.
The word efficient means that the user can search the required data quickly. The word compact means that the stored data occupies as little space as possible in a computer.
Table
The table is the fundamental object of the database structure. The basic purpose of a table is to store data. A table consists of rows and columns. A table is a very convenient way to store data. The data in tables can be manipulated easily.
|
Serial No |
Name |
Qualification |
|
|
1 |
Usman |
B.Sc. |
usman@itseries.com.pk |
|
2 |
Abdullah |
M.Sc. |
abdullah@itseries.com.pk |
|
3 |
Ejaz |
M.Sc. |
Ejaz@itseris.com.pk |
Table: Record table
Rows/Record
Rows are the horizontal part of the table. It is a collection of related fields. For example, the above table has three rows. Each row contains a record of a different person.
|
2 |
Usman |
B.Sc. |
Usman@itseries.com.pk |
Columns / Field
Columns are the vertical part of the table. For example, all values in the above table under the “Name” field make a column.
|
Name |
|
Usman |
|
Abdullah |
|
Ejaz |
A single column
Examples of Database
Following are some important examples of databases:
1. Phone Directory
The phone directory is a simple example of a database. A phone directory stores the phone numbers of different persons. Searching a phone number from a phone directory is very easy as all phone numbers are stored in an organized way.
2. Library
A library contains thousands of books. It is very difficult to handle the records of all these books without a database. The system can be used to store the records of books, members of the library, issuance, and recovery of books, etc. The database can be used to search the required books easily. This database can help for doing research work.
3. Accounts
A database is used to control the accounts system of an organization. The accounts database keeps the record of all financial transactions of the organization. It can be used to perform different calculations to find information about the business such as annual profit, trail balance, and ledger, etc.
4. College
A college has many students in different classes. A database may be used to keep the records of the student, fee transactions, examination information, and other data of the college. It can also store the attendance of the students.
Database Management System
A database management system (DBMS) is a collection of programs that are used to create and maintain a database. DBMS is general-purpose software that provides the following facilities:
- It provides the facility to define the structure of the database. The user can specify data types, formal and constraints for the data to be stored in a database.
- It provides the facility to store data on some storage medium controlled by DBMS.
- It provides the facility to insert, delete, update and retrieve specific data to generate reports, etc.
Components of database Environment
The important components of the database environment are as follows:
1. Repository
A repository is a collection of all data definitions, data relationships, output styles, and reports, etc. All this information is the metadata that is important to manage the database.
2. Database management System
A Database management system (DBMS) is a collection of programs that are used to create and maintain a database.
3. Database
The database can be defined as an organized collection of related data. The work “organized” means that data is stored in such a way that the user can store, manipulate and retrieve data easily. The word means that a database is normally created to store the data about a particular topic.
4. Application program
An application program is a program that is used commands to the database management system to manipulate the database. These commands are sent to the DBMS through the graphical user interface. The user interacts with the application program and the application program further interacts with the database management system. Two important application programs are Developer2000 and Power Builder.
5. User Interface
The user interface is a visual environment that is used by the user to communicate with the computer. It consists of menus, buttons, and other components. All windows based software uses a graphical user interface. The user interface consists of the following components:
- Forms: the forms are used to enter data in the database. A form consists of text boxes, labels, and buttons that are used by the users for entering data easily. The user can also retrieve, change, and update data by using forms.
- Menus: menus are a list of commands for performing different operations. Menus are frequently used in windows-based applications. The user can use them easily for manipulating the database.
- Reports: Reports are the output of the database. The user can generate different types of reports by manipulating the database. The information on the reports is arranged in different forms and may contain graphs, charts, and tables, etc.
6. Data Administrators
Data administrators are the persons who are responsible for the whole information system they authorize access to the database as well as coordinate and monitor the usage of the database.
7. System
System analysts determine the requirements of end-users and develop specifications for transactions. Application programmers implement these specifications and programs.
8. End-User
End users are those persons who interact with the application directly. They are responsible to insert, delete and update data in the database. They get information from the system as and when required.
