12th Class Computer Chapter 8 Introduction to Database Short Questions Answer

Most of us encounter several activities that involve some interaction with a database. For example if we go to the bank to deposit or withdraw money, if we make a hotel or airline reservation or if we access a computerized library catalogue to search for a book.

Duplication of data in many different files is known as data redundancy. For example details of a salesperson’s name address and pay rate might be held on a payroll file for calculating the payroll.

Having different values for the same data items in different files is known as data inconsistency. The payroll department i.e. may change the commissions rates paid to sales staff but the sales Department file may fail to update its files and so be producing reports calculated with out-of-date figures.

In such a system when information of a non-routine nature is needed, it can take weeks to assemble the data from the various files and writes new programs to produce the required reports.

In order to solve the problems of traditional file approach the concept of a database was introduced.

A database is a collection of related data.

All the data belonging to the entire organization is centralized in a common pool of data, accessible by all applications. This solved the problem of redundancy and inconsistency.

1. A database can be of any size and complexity.
2. A database may be generated and maintained manually or it may be computerized.

DBA stands for Database Administrator. It defines as a person for supervising both the database and the use of DBMS.

A group responsible for supervising both the database and the use of DBMS.

A database management system (DBMS) is a collection of programs that enables users to create and maintain a database.

The DBMS is a general-purpose software system that facilitates the process of defining, constructing and manipulating databases for various applications.

Constructing a database is the process of storing the data itself on same storage medium that is controlled by the DBMS.

Manipulating a database includes such functions as querying the database to retrieve specific data, updating the database to reflect changes and generating reports from the data.

An effective DBMS provides users with timely, accurate and relevant information is stored in computer files, which need to be suitably organized and properly maintained to that users can easily access the information they need.

All data is stored in a computer’s memory or storage devices in the form of binary digits orbits. A bit can be either ‘ON’ or ‘OFF’ representing 1 or 0.

Bits are grouped together, with a group of eight bits forming a byte. One byte can represent one character or in different content, other data such as sound, part of a picture etc.

ASCII is the abbreviation of American Standard code for Information Interchange. Using 8 bits to make it is possible to represent 256(28) different characters.

Characters are grouped together to for fields. Data held about a person, for example, may be split into many fields including ID Number, Surname, Initials, Title, Street, Village, Town, Date of Birth and so on.

All the information about one person or item is held in a record when records are stored in a table rows represent records and columns represent fields.