Database 

                  

• Database is a collection of organized interrelated data items.
  
• It represents some aspects of the real world which is also known as miniworld.
  
• Database is developed for a specific purpose such as a company may develop a database to keep track of employees and generate reports

Why Use a Database 

• We like to keep collections of various things such as stamps, photos, feathers etc.
  
• If you collect anything, there should be a way to manage the collection.
  
• One way to keep track of a collection is to create a database.
  
• So that it is easy to manipulate a large collection of data by creating frequently using queries and reports.  

Database Management System (DBMS) 

• DBMS is a software package that organizes data into records in one or more databases.
  
• It acts as a software interface between users and databases. This helps users to easily access the data in a database.
  Eg: Microsoft Access, Oracle, SQL Server.
  
• The Relational Database Management System is the most common type of DBMS.
  
• More over it allows organizing data in a variety of formats for displaying purposes.
  Eg: Same data can be viewed as a graph or in tabular format.

• From the use of computers to perform business functions, companies have used the traditional approach to process their functions.
  
• In this approach, everything was recorded on paper, enclosed in separate files according to the application and stored in filing cabinets.
  Eg: Filling an employee application form and putting it in the employee file.
  
• Problems of the traditional approach were; Data
  Redundancy 
  Lack of Data Integration
  Data Dependence

• When an organization used to maintain independent data files for each department, it caused duplication of data which is called redundancy.
  Eg: Customer’s name and address can be recorded and stored in several files within the organization.
  
• Practical difficulties arose, when updating, deleting or inserting data. Same data had to be changed in several files.
  
• Inconsistency of data, occurred among data that has been stored in separate files

• Having data in independent files made it difficult to provide direct information to end users that require accessing data stored in several different files.
  
• Special computer programs had to be written to retrieve data from each independent file.
  
• End users had to extract the required information manually, from various reports produced by each separate application and prepare customized reports for the management.
  
• This was a difficult time consuming, costly task for organizations which made it impossible to provide end users or management with such information.

• Major components of a file processing system depended on one another in significant ways. (The organization of files, their physical locations on storage hardware, and the application software used to access those files)
  Eg: Application programs typically contain references to the specific format of the data stored in the files they use.
  
• Changes in the format and structure of data and records in a file required that changes be made to all of the programs that used that file.
  
• This program maintenance effort was a major burden of file processing systems. It proved difficult to do properly.
  
• It resulted in a lot of inconsistency in the data files.