GATE Computer Science Engineering(CSE) 2027 Test: Database Management System

DBMS is abbreviated as Database Management System. Database Management System stores the data and allows authorized users to manipulate and modify the data.

DBMS is nothing but a storehouse wherein the authorized user can create a database to store, modify or retrieve the organized data in the table. It can be modified or retrieved by users who have access to DBMS only.

The reason for creating the database management system was to store large data and these data can be of any form image, text, audio, or video files, etc. DBMS allows the users to store and access the data of any format.

The important features of a database management system are:
1) Minimum Duplication and Redundancy of Data
2) High Level of Security
3) Mulitple-user Access
4) Support ACID Property

It allows authorized users to update, store, manipulate, or access data. Since data is stored in table format it is easy to access the data and perform the required functions. It also removes duplicate and redundant data.

The components of DBMS are as follows:
1) Hardware: Like a hard drive, monitor, etc.
2) Software: Provides a user interface
3) Data Manager: Manages operations of DBMS.
4) Data: The collection of information on the DB is known as data.
5) Data Languages: Languages like DDL, DML, DAL, and DCL allow to perform operations like creating, modifying, storing, or retrieving data.

Information about data is known as Metadata. Metadata describes the data in detail by providing additional information like type, length of the data, etc. Metadata helps the user to understand the data.

Consider 2 relations r1 and r2. r1 may include among its attributes the primary key of relation r2. This attribute is called a foreign key from r1, referencing r2. The relation r1 is also called the referencing relation of the foreign key dependency, and r2 is called the referenced relation of the foreign key.

A database management system is an application that acts as an interface between the user and the database. The user interacts with the application to access data.

Foreign key creates a relationship between two relations. Super key is the superset of all the keys in a relation. A candidate key is used to identify tuples in a relation.