A database is a collection of logically related data sets or files. Each file may contain different type of information and are used for specific purposes. The files may be organized in different ways to meet different processing and retrieval requirements of the users.
A bank may have separate files for the clients as follows:
- Saving Accounts
- Current Accounts
- Automobile Loan
- Personal Loan
- Client Information etc.
The client database of bank will consist of the records from all of the above files. The data of any client can be added, retrieved or updated easily using database programs.
Facilities of Database
A database system normally provides the following facilities to the user:
- Adding new files to database
- Inserting new data in existing files
- Retrieving data from existing files
- Updating data in existing files
- Deleting data from existing files
- Removing existing files from database
Objectives of Database
The main objective of using database are as follows:
- Data Integration
- Data Integrity
- Data Independence
1. Data Integration:
The data in file system is stored in separate files. It is very difficult to access data stored in separate and independent files. An important objective of database is to solve this problem. The data in database may be located at different computers physically but it is connected through data communication links. In this way, data appears centralized logically.
2. Data Integrity:
Data Integrity means the reliability and accuracy of data. Integrity rules are designed to keep the data consistent and correct. These rules act like a check on the incoming data. Enforcing data integrity ensures the quality of data in the database. DBMS provides several methods to enforce integrity of the data in a database.
For example, an integrity rule can make sure that the same. Employee ID is not assigned to multiple employees.
3. Data Independence:
Database approach provides the facility of data independence. It means that the data and the application programs are separate from each other. The user can change data storage structures and operations without changing the application programs. The user can also modify programs without reorganization of data.