Unit-4: Data Base Management System Part-1

Concept of Database

A database is a collection of related data which is organized to easy to access, update and manages. Any small portion of information is a data and also called facts and figure is data. Actually a database piece of information is stored and performs various operations.

The basic Building Block of database

1. Bit: the smallest unit of a data. It is either 0 or 1.
2. Byte: A group of 8 bit is called Byte or character which can be letter or numbers etc.
3. Field: In a database the table column is represents as a Field. It is a logical collection of character is called the field.
4. Record: A collection of multiple attributes or field is called record. It is also known as tuple.
5. File: Collection of one or more record is called file.
6. Table: Collection of related multiple records.
7. Database: Collection of interrelated files.

Data vs information

Data	Information
Data is a row fact and figure	The processed form of data is called information
Not organized manner	Organized manner
Not meaningful	Meaningful
Input to the system	Output to the system
It is not used in decision making plan (DMP)	It is used in decision making plan (DMP)

Data Base Management System (DBMS):

DBMS is a collection of interrelated data and set of programs to access those data. This is used to storing and retrieving user’s data with most efficiency and appropriate security.

DBMS is defines as a software system that allows user to define create, maintain and control the access of database.

Features of Database management system

1. Data shared: Data can be share by authorized users easily.
2. Data consistency: it reduced the data redundancy or duplicate data will be removed. It maintenance a data consistency. data inconsistency occurs means it duplicates a data
3. Security: Data should be protected from the unauthorized users.
4. Validity: Data should be correct with real word entity. It is also known as data integrity.
5. Concurrent Access: multiple user’s can be access data simultaneously
6. Non Redundancy: Duplicate data should not be allowed