JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD
JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD MCA II DATABASE MANAGEMENT SYSTEMS Previous Question Paper (June/July - 2018 - R13)
Part A is compulsory which carries 20 marks. Answer all questions in Part A. Part B consists of 5 Units. Answer any one full question from each unit.
Part A
For what reasons database management system is preferred over file system?
Answer
A database management system (DBMS) is preferred over a traditional file system for several key reasons:
- Data Redundancy and Inconsistency: DBMS minimizes duplicate data, ensuring consistency across the system.
- Data Isolation: Data is stored in a structured format, making it easier to retrieve and manipulate compared to scattered files.
- Concurrent Access: DBMS allows multiple users to access data simultaneously while maintaining integrity through locking mechanisms.
- Security and Integrity: DBMS provides centralized control, enabling fine-grained access rights and enforcement of integrity constraints that are difficult to manage in file systems.
What is the use of outer join? Give its types.
Answer
An outer join is used to retrieve rows from tables even when there is no matching record in the joined table. Unlike inner joins, which only return matching rows, outer joins preserve unmatched data by filling missing columns with NULL values. Its types are:
- Left Outer Join: Returns all records from the left table and the matched records from the right table.
- Right Outer Join: Returns all records from the right table and the matched records from the left table.
- Full Outer Join: Returns all records when there is a match in either the left or right table.
Define multi valued dependency.
Answer
Sign in to view the complete answer paper.
Suggest any one mechanism for media recovery.
Answer
Sign in to view the complete answer paper.
Define track, sector, cylinder of disk.
Answer
Sign in to view the complete answer paper.
Part B
How does database management system provide data abstraction? Explain with illustrations.
Answer
Sign in to view the complete answer paper.
Construct an ER diagram to design a database for online movie ticket booking application such as bookmyshow.com.
Answer
Sign in to view the complete answer paper.
Consider the following database schema to write queries in Relational Algebra. Student ( Sid, Sname, total_credits), Course( Cno, Ctitle, Number_of_credits), Enroll(Sid, Cno, Grade)
Find the students’ names who secured “A” grade in DBMS course.
Answer
Sign in to view the complete answer paper.
Find the titles of the courses which do not have enrollment of any student.
Answer
Sign in to view the complete answer paper.
What is an assertion? How to define assertion in SQL? Explain with suitable example.
Answer
Sign in to view the complete answer paper.
Describe the need of schema refinement. What is the effect on database if this phase is skipped by the designers?
Answer
Sign in to view the complete answer paper.
How to compute the attribute closure?
Answer
Sign in to view the complete answer paper.
What is meant by partially functional dependent?
Answer
Sign in to view the complete answer paper.
What is a transaction? What is a schedule? What is meant by serializability? Quote examples for all these.
Answer
Sign in to view the complete answer paper.
List the different types of failures and explain log based recovery for concurrent transactions.
Answer
Sign in to view the complete answer paper.
Make a comparison of the three file organizations- heap, sorted, hash.
Answer
Sign in to view the complete answer paper.
Demonstrate bulk loading of B+ tree. Consider suitable student data records and construct B+ tree structure.
Answer
Sign in to view the complete answer paper.