JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD
JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD MCA 2019 DATABASE MANAGEMENT SYSTEMS Previous Question Paper (April/May - 2019 - 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
Define types of data models and explain briefly in one line each.
Answer
Data models are conceptual tools used to describe data, data relationships, and constraints. The primary types are:
- Relational Model: Represents data in the form of tables consisting of rows and columns.
- Entity-Relationship Model: Uses entities, attributes, and relationships to represent real-world objects.
- Object-Oriented Model: Organizes data as objects containing both data and methods.
- Hierarchical/Network Models: Represent data using tree-like or graph-like structures respectively.
What are set operations?
Answer
Set operations are relational algebra operations used to combine the results of two compatible relations into a single result set. The fundamental set operations include:
- Union (∪): Combines all tuples from two relations, removing duplicates.
- Intersection (∩): Returns only the tuples that are present in both relations.
- Set Difference (−): Returns tuples that exist in the first relation but not in the second.
- Cartesian Product (×): Combines every tuple of the first relation with every tuple of the second.
Explain BCNF.
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Discuss on Lock based concurrency control.
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What are primary and secondary indexes?
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PART - B
What is meant by ER model? Explain how an ER diagram can be converted into relations.
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Explain how to destroy/alter Tables and views?
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Write a note on database architecture.
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Explain the role of file manager and buffer manager in DBMS.
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Explain Division in relational algebra.
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Explain about nested queries and correlated nested queries in the SQL.
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What are aggregate operators in SQL? Explain them with suitable examples.
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Discuss the need for schema refinement. Explain the third and fifth normal form and inclusion dependencies.
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Describe about the Multi-Valued Dependencies and Fourth normal form with suitable examples.
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Define these terms: atomicity, consistency, isolation, durability, schedule, blind write, dirty read, unrepeatable read, serializable schedule, recoverable schedule, avoids-cascading-aborts schedule.
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Explain about Concurrent execution of transactions.
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Explain Dead lock prevention policies employed in databases.
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Briefly discuss write ahead log protocol.
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Define the Tree structured Indexing Hash based indexing with simple illustrations.
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Explain the File organization types and its techniques.
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