Most Frequently Asked DBMS Interview Questions

Q1. What is a data?

Database is a collection of information organized for easy access, management and


  • Telephone directory
  • Customer data
  • Product inventory
  • Visitors’ register
  • Weather records

Q2. Types Of Data Model ?

Record based logical model

  • Hierarchical data model
  • Network data model
  • Relational data model
  • Entity relationship model

Object based logical model

  • Entity relationship model

Q3. Operations in DBMS?

  1. Adding new files
  2. Inserting data
  3. Retrieving data
  4. Modifying data
  5. Removing data
  6. Removing files

Q4. Advantages Of Database?

  • Sharing of data across applications
  • Enhanced security mechanism
  • Enforce integrity constraints
  • Better transaction support
  • Backup and recovery features

Q5. What is a RDBMS?

  • RDBMS stands for “Relational DataBase Management System.
  • A relational database refers to a database that stores data in a structured format, using
    rows and columns.
  • This makes it easier to locate and access specific values within the database.
  • It is “relational” because the values within each table are related to each other. Tables may also be related to other tables.
  • The relational structure makes it possible to run queries across multiple tables at once.

Q6. Some Features of RDBMS?

  • Features of RDBMS
  • Every piece of information is stored in the form of tables
  • Has primary keys for unique identification of rows
  • Has foreign keys to ensure data integrity
  • Provides SQL for data access
  • Uses indexes for faster data retrieval
  • Gives access privileges to ensure data security

Q7. Difference Between RDBMS and Traditional Approach?

RDBMS applications store data in a tabular form.
Tradition Approach, applications store data as files.
In RDBMS Table Represent “Relation” between the tables.In traditional approach, data is generally stored in either a Hierarchical form/navigational form.

Q8. What is a Normalization ?

Normalization is a method to remove all these anomalies and bring the database to a consistent state
Mainly there are three types of anomalies:- 1)Update anomalies 2) Deletion anomalies 3) Insert anomalies

  • Decompose larger, complex table into simpler and smaller ones.
  • Moves from lower normal forms to higher normal forms.

Q9. Need Of Normalization ?

  • Try to remove all types of anomalies.
  • In order to produce good database design.
  • To ensure all database operations to be efficiently performed.
  • Avoid any expensive DBMS operations.
  • Avoid unnecessary replication Of information

Q10. What is a Functional Dependency ?

Functional dependency (FD) is a set of constraints between two attributes in a relation. Functional dependency says that if two tuples have same values for attributes A1, A2,…, An, then those two tuples must have to have same values for attributes B1, B2, …, Bn.

Functional dependency is represented by an arrow sign () that is, X→Y, where X functionally determines Y. The left-hand side attributes determine the values of attributes on the right-hand side.