(SEM V) THEORY EXAMINATION 2020-21 DATABASE MANAGEMENT SYSTEM

SECTION A (Any 2 Questions Explained Briefly)
 

What is Data Independence in DBMS?
Data independence refers to the ability to change the database schema at one level without affecting the schema at the next higher level. It allows modifications in physical storage or logical structure without changing application programs, which makes the system flexible and easy to maintain.
 

What are ACID properties of a transaction?
ACID properties ensure reliable database transactions. Atomicity ensures all operations of a transaction are completed or none at all, Consistency maintains database correctness, Isolation ensures concurrent transactions do not interfere with each other, and Durability guarantees that committed data is not lost even after system failure.
 

SECTION B (Any 2 Questions Explained)
 

What is an ER Diagram? Explain its components.
An Entity Relationship diagram is a conceptual model used to represent the structure of a database. It consists of entities, attributes, and relationships. Entities represent real-world objects, attributes describe entity properties, and relationships show how entities are connected. ER diagrams help in designing databases clearly before implementation.
 

Explain Relational Algebra and its operations.
Relational algebra is a procedural query language used to retrieve data from relational databases. It includes operations such as selection, projection, union, set difference, Cartesian product, and join. These operations form the foundation of SQL and help in database query processing.
 

SECTION C (Any 2 Questions Explained)
 

What is Data Abstraction in DBMS?
Data abstraction hides unnecessary details from users and shows only relevant information. It is achieved using three levels: physical level, logical level, and view level. This approach simplifies database interaction and improves security and efficiency.
 

Explain Functional Dependency.
Functional dependency describes the relationship between attributes in a relation, where one attribute determines another. It is a key concept in normalization and helps reduce redundancy and improve data integrity by organizing data efficiently.
 

Most Questions in This PDF Are Related To
 

Most questions in the Database Management System (KCS-501) paper are related to ER modeling, relational algebra, normalization and functional dependency, SQL and PL/SQL, transaction management, concurrency control techniques, recovery methods, and database design concepts. The paper mainly focuses on designing reliable, consistent, and efficient database systems.