tutorialcup@gmail.com

DBMS Tutorial

DBMS Tutorial
Characteristics of a DB
Data Independence
Components of Database
Architecture of Database
Structure of DBMS
File Processing System
Database Management System
Database Schema
Database Instance
Database Languages
Data Definition Language (DDL)
Data Manipulation Language (DML)
Data Control Language (DCL)
Transaction Control Language (TCL)
Database Interface
Data Models
Object based Data Models
Physical Data Models
Record based Data Models
Basic Concepts of ER Data Model
ER Data Model
Convert ER Diagram into Tables
Database Abstraction
Database Users and Administrators
Relational Query Languages
Relational Calculus
File Organization
Sequential File Organization
Heap File Organization
Hash File Organization
Indexed Sequential Access
B+ Tree File Organization
Cluster File Organization
Data Dictionary
Data Dictionary Structure
Data Dictionary Functions
Indexing Basics
B+ Tree
Multiple Key Access
Hashing Concepts
Bitmap Index
Database Index
Relational Models
Database Keys
Database Constraints
Database Integrity
Relational Set Operators
System Catalog
Codd’s Rule
Normalization
First Normal Form (1NF)
Second Normal Form (2NF)
Third Normal Form (3NF)
Boyce-Codd Normal Form (3.5NF)
Fourth Normal Form (4NF)
Fifth Normal Form (5NF)
De-normalization
Normalization Vs De-normalization
Database Transaction
Schedules in DBMS
Concurrency Control
DBMS Deadlock
Data Backup And Recovery
Exceptions in DBMS
Triggers
DataTypes and Variables
Advanced SQL
Select Operation
NULL Values
Sorting

Database

Name itself indicates what it is. Database is a place/container where all the data is stored. But what is data?  In a database, even a smallest piece of information becomes data. For example, Student is a data, course is a data, and Color is a data, height, weight, food everything is data. In short, all the living and non-living objects in this world is a data.

Why we need data?

We need data so that we can perform various actions on them. Say, we do not have any database and we want to record what is the height and weight of a baby in a year. What we do is note it in a piece of paper every month. At the end of the certain period or year, we would check up if he/she is growing correctly. If some entry is wrong or irrelevant, we correct it or strike it off. Same is done using database. We would be storing all these information in the database. If we want to check the growth, we would be pulling the information from the database, if we need to change any information, we can update/delete them. But all the data will be at one place - Database.

What type of data is stored in database?

In a database, we would be grouping only related data together and storing them under one group name called table. This helps in identifying which data is stored where and under what name. It reduces the time to search for a particular data in a whole database. For example, Student, Teacher, Class, Subject, Employee, Department etc form individual tables.

DBMS Tutorial      DBMS Tutorial

And for whom these datas are stored?

We store only related data - related to one particular requirement / application. For example, Student database - it will have all the information of students ranging from his ID, Name, Date of birth, class, to grade, prizes who are studying in a particular College.

How do we determine which data is relevant to be put in a particular database?

It all depends on what database we are developing, and what is the exact requirement/purpose of it. Say, we need to create College database. What could college database contain? First thing is that we need to store college information like its name, address. Next comes courses offered in that college, Staffs and their details, students and their details.  But do we store all these information under one table - College? Will database be quick in getting the data or updating? Certainly Not!  It would become a chaos if everything is stored in a single table. Hence they introduce certain rules to manage the database - relational database management system (RDBMS). RDBMS is a program that guides us how to create and maintain a database. It tells us how to divide related information into different tables and inter-relate them so that we can select/insert/update/delete all the related data easily and efficiently.

SQL Interview Questions


Next >
Scroll to Top