RDBMS Exam – Paper 1

Part A (10 × 1.5 = 15 marks)

1. What is Object-Oriented Modeling, and why is it used in databases?
2. Define Generalization and Specialization in the E-R model.
3. What is Encapsulation, and how is it implemented in Object-Oriented Databases?
4. What are the key components of Distributed Database Design?
5. Explain the concept of Data Placement in DDBMS.
6. Define Two-Phase Locking in concurrency control.
7. What is the difference between Heuristic and Cost-Based Query Optimization?
8. Explain the need for Temporal Databases with an example.
9. What is Public Key Cryptography, and why is it important in database security?
10. What are Security Specifications in SQL?

Part B (5 × 3 = 15 marks)

11. How does Inheritance work in Object-Oriented Database Models?
12. Explain the architecture of Distributed Processing Systems.
13. What is Concurrency Control, and why is it necessary?
14. What are the different types of Encryption Techniques used in databases?
15. Explain the DTD Schema in XML with an example.

Part C (3 × (7+7+6) = 20 marks)

16. (a) Explain in detail the Architecture of a Distributed Database System. (7)
    OR
    (b) Describe the different types of attributes in Object-Oriented Modeling. (7)

17. (a) Explain the algorithm for External Sorting used in query processing. (7)
    OR
    (b) Describe the importance of Query Optimization and different techniques. (7)

18. (a) What is Data Mining? Explain Association Rules and their applications. (6)
    OR
    (b) Explain Security and Integrity Constraints in Databases. (6)

Part A (10 × 1.5 = 15 Marks)

1. What is Object-Oriented Modeling and why is it used in databases?

Answer:
Object-Oriented Modeling (OOM) is a database design method where data is stored as objects and classes. It includes concepts like Encapsulation, Inheritance, Polymorphism, and Abstraction.
Reasons for its use:

• Data can be stored and managed well.
• No need for repetitive writing, making system management easier.
• Even complex data can be understood and used in a simple form.

2. What are Generalization and Specialization?

Answer:

• Generalization: In this, more than one entity is combined to form a general entity.
  Example: "Car" and "Bike" can be combined to form "Vehicle".
• Specialization: In this, an entity is divided into smaller parts.
  Example: "Employee" can be divided into "Manager" and "Clerk".

3. What is Encapsulation and how is it implemented in Object-Oriented Databases?

Answer:
Encapsulation means keeping data and its related functions (methods) together.
It is implemented in Object-Oriented Databases through Classes and Objects, where

• Data fields (attributes) and
• Methods (functions)
  are kept together.

Example:

class Student {
private int rollNo;
public void setRollNo(int r) { rollNo = r; }
public int getRollNo() { return rollNo; }
}

This prevents data from being changed without permission.

4. What are the main parts of Distributed Database Design?

Answer:
The main parts of a Distributed Database System (DDBMS) are:

1. Data Fragmentation – Dividing data into smaller parts.
2. Data Replication – Keeping multiple copies of data.
3. Data Allocation – Storing data in the right place.
4. Concurrency Control – Controlling data access by multiple users.
5. Recovery Mechanism – Restoring data after a system failure.

5. What is Data Placement and why is it important in DDBMS?

Answer:
Data Placement means placing data in the right location to ensure good system speed.
There are three types of Data Placement in DDBMS:

1. Centralized Placement – All data is kept in one place.
2. Partitioned Placement – Data is divided into smaller parts and stored on different servers.
3. Replicated Placement – Multiple copies of data are created.

It is important because:

• The system works faster.
• It reduces pressure on the network.
• Data remains secure.

6. What is Two-Phase Locking?

Answer:
Two-Phase Locking (2PL) is a method to control multiple concurrent tasks in a database to prevent data corruption.
It has two phases:

1. Growing Phase – Locks can be acquired but not released.
2. Shrinking Phase – Locks can be released but not acquired.

Example:
If a bank account is being updated, no other user can access it until the entire process is complete.

7. What is the difference between Heuristic and Cost-Based Query Optimization?

Answer:

8. Why is a Temporal Database needed? Give an example.

Answer:
A Temporal Database is a database that stores changes to data over time.
Example:

• If an employee's salary was ₹20,000 in 2015 and became ₹50,000 in 2023, the Temporal Database will store both pieces of data.
• Keeping a patient's medical records in a hospital.

9. What is Public Key Cryptography and why is it important for Database Security?

Answer:
Public Key Cryptography uses two keys:

1. Public Key – Known to everyone.
2. Private Key – Only the receiver has it.

It is important for Database Security because:

• Data is kept secure.
• Unauthorized Access is prevented.
• Secure communication can be established.

10. What are Security Specifications in SQL?

Answer:
In SQL, these are the methods for database security:

1. Access Control – Deciding who can access the data.
2. Flow Control – Controlling how data is sent and received.
3. Encryption – Storing data in a secure format.
4. User Authentication – Verifying user identity with a Password and Login System.

Example:

GRANT SELECT ON employees TO user1;
REVOKE INSERT ON employees FROM user2;

Part B (5 × 3 = 15 Marks)

11. How does Inheritance work in Object-Oriented Databases?

Answer:
Inheritance means that one class can use the properties and methods of another class.
Example:

class Animal {
void eat() { System.out.println("Eating..."); }
}
class Dog extends Animal {
void bark() { System.out.println("Barking..."); }
}

Here, "Dog" inherits the properties of "Animal".

12. Explain the Architecture of a Distributed Processing System.

Answer:
In a Distributed Processing System, data and processing are distributed across multiple computers for better performance.
Its main types:

1. Client-Server Architecture – The client requests data, the server provides it.
2. Peer-to-Peer Architecture – All systems are directly connected to each other.
3. Multi-Tier Architecture – Data is managed at different levels.

13. What is Concurrency Control and why is it necessary?

Answer:
Concurrency Control is a method that allows multiple users to use the same data correctly at the same time.
Why is it necessary?

• It prevents data from getting corrupted.
• It reduces the problem of Deadlock.
• It maintains good system performance.

Part C (3 × (7+7+6) = 20 Marks)

1 (a) Explain the Architecture of a Distributed Database System in detail. (7 Marks)

Answer:
A Distributed Database System (DDBMS) is a system where data is distributed across multiple computers or servers, and all systems work together as one.

Main parts of DDBMS Architecture:

1. Centralized Architecture:

   • It has a main server that controls all the data.
   • All clients connect to this server to access data.

2. Client-Server Architecture:

   • In this, clients send requests for data, and the server processes them and sends back a response.
   • Example: In a banking system, when a customer (Client) checks their account, the data comes from the server.

3. Peer-to-Peer Architecture:

   • In this, all systems connect directly to each other without needing a server.
   • Example: Bitcoin and Torrent systems are of this type.

4. Multi-Tier Architecture:

   • In this, data is processed at different levels (Layers).
   • Example: An e-commerce website works in three layers: UI (front-end), server (back-end), and database.

OR

1 (b) Explain the different types of Attributes in Object-Oriented Modeling. (7 Marks)

Answer:
In Object-Oriented Modeling (OOM), Attributes are used to store data.

Main types of Attributes:

1. Simple Attribute:

   • It stores only a single value.
   • Example: In a Student entity, "Roll No" is a Simple Attribute.

2. Composite Attribute:

   • It has more than one sub-attribute.
   • Example: "Name" is a Composite Attribute, which can have "First Name" and "Last Name".

3. Derived Attribute:

   • It is data derived from the value of another attribute.
   • Example: "Age" can be derived from "Date of Birth".

4. Multivalued Attribute:

   • It can store more than one value.
   • Example: "Phone Numbers" is a Multivalued Attribute because a person can have more than one number.

5. Key Attribute:

   • It is a Unique Identifier that distinguishes an entity.
   • Example: "Aadhar Number" or "Roll No" can be a Key Attribute.

2 (a) Explain the Algorithm used for External Sorting in Query Processing. (7 Marks)

Answer:
External Sorting is the process of sorting a large database using Secondary Storage (like a hard disk).

Algorithm for External Sorting:

1. Merge Sort Algorithm:

   • In this, data is sorted by dividing it into smaller parts and then merging them to create the complete dataset.

2. Multiway Merge Sort:

   • This is different from Traditional Merge Sort because it merges multiple sequences at once.

3. Replacement Selection Sort:

   • In this, data is stored in some parts, and the data that is used more frequently is accessed quickly.

OR

2 (b) Explain the importance of Query Optimization and describe different Techniques. (7 Marks)

Answer:
Query Optimization means executing a query in such a way that it is completed in the least amount of time and with the fewest resources.

Why is Query Optimization needed?

• Reduces Execution Time.
• Reduces Server Load.
• Improves Database Performance.

Query Optimization Techniques:

1. Heuristic-Based Optimization:

   • In this, the query is optimized according to Predefined Rules.
   • Example: Using *"SELECT column_name" instead of "SELECT " in SQL.

2. Cost-Based Optimization:

   • In this, the Query Execution Plan is analyzed, and the query with the lowest cost is chosen.

3. Join Optimization:

   • In this, the most efficient way to join tables is chosen.
   • Example: Nested Loop Join, Hash Join, Merge Join.

3 (a) What is Data Mining? Explain Association Rules and their uses. (6 Marks)

Answer:
Data Mining is the process of extracting important information from a database and using it for decision-making.

What are Association Rules?

Association Rules are rules that tell us which items are used together most often.

Example:

If 80% of customers who buy "Bread" also buy "Butter", this becomes an Association Rule.

Uses of Association Rules:

1. Market Basket Analysis:
   • Companies use this to find out which products are bought together most often.
2. Fraud Detection:
   • Banks and credit card companies use this technique to detect fraud.
3. Recommendation Systems:
   • Companies like Amazon and Netflix suggest Products and Movies based on user preferences.

OR

3 (b) Explain Security and Integrity Constraints in a Database. (6 Marks)

Answer:
Database Security means protecting data from Unauthorized Access, and Integrity Constraints mean maintaining the accuracy of data.

Important parts of Database Security:

1. Authentication:
   • Verifying a User's identity with a Username and Password.
2. Authorization:
   • Deciding which User can view or change which data.
3. Encryption:
   • Converting data into a Code Format to keep it secure.

Types of Integrity Constraints:

1. Primary Key Constraint:

   • Each Row must have a Unique ID.
   • Example: In a Student Table, the Roll No will always be Unique.

2. Foreign Key Constraint:

   • One Table is linked to another Table, and it is necessary to maintain a relationship in the data.

3. Not Null Constraint:

   • Some data Fields cannot be left empty.
   • Example: In an Employee Table, "Employee ID" cannot be empty.

4. Check Constraint:

   • Used to keep the value of a Column within a certain range.
   • Example: Salary must be > 5000.

RDBMS Exam – Paper 2

Part A (10 × 1.5 = 15 marks)

1. What is a Relational Database?
   Answer: A Relational Database is a type of database where data is stored in Tables (Relations). Each table has Rows (Records) and Columns (Attributes). Tables are linked together using Primary Keys and Foreign Keys, which allows for efficient storage, access, and management of data. Examples of Relational Databases are MySQL, PostgreSQL, and Oracle.

2. Define Aggregation in the E-R model.
   Answer: Aggregation is a concept in the E-R model where a relation is considered part of another relation. It is useful when we need to combine two or more Entities and their relationships into a Higher-Level Entity.

3. What is the role of Data Communication in DDBMS?
   Answer: The main function of Data Communication in a Distributed Database System (DDBMS) is to transfer data between different locations (servers). It helps to conduct data exchange quickly and securely.

4. Explain the Need for Transaction Recovery.
   Answer: Transaction Recovery is needed when a transaction remains incomplete due to a system crash, network failure, or other technical problems. It is necessary to bring the data back to a consistent state.

5. What is the difference between Data Warehousing and Database Views?
   Answer:

   • Data Warehousing: It is a technique for storing and analyzing large amounts of data.
   • Database Views: It is a virtual table of a database, which accesses data from the actual table but does not store data itself.

6. What is Serializability in Transactions?
   Answer: Serializability means that multiple transactions are executed in such a way that their effect is like a Sequential Execution. It helps in maintaining data consistency.

7. Define Multi-Media Databases with an example.
   Answer: A Multi-Media Database is a database that stores text, images, videos, audio, graphics, etc.
   Example: Platforms like YouTube and Facebook use multimedia databases.

8. Explain the XML Tree Data Model.
   Answer: In the XML Tree Data Model, data is organized in a Tree Structure.

   • The Root Element is at the top.
   • Below it are Sub-elements and Attributes.
     Example:

   
   Rahul
   22
   
   

9. What is the difference between Access Control and Flow Control in Database Security?
   Answer:

   • Access Control: It determines which user can access which data.
   • Flow Control: It ensures that data flows correctly and securely from one place to another.

10. What is a Data Layer in Data Warehousing?
    Answer: The Data Layer is the layer where data is stored, processed, and analyzed. It is an important layer of Data Warehousing.

Part B (5 × 3 = 15 marks)

1. Explain Object and Set Operations in Query Processing.
   Answer:

   • Object Operations: These are based on Objects, such as Insert, Update, and Delete.
   • Set Operations: This includes operations like Union, Intersection, Difference, and Cartesian Product.

2. What is Classification in Data Mining? Give an example.
   Answer: Classification is a Data Mining Technique in which data is divided into different categories.
   Example: Classifying bank customers as "Low Risk" and "High Risk".

3. Describe the Placement of DDBMS Components.
   Answer: DDBMS Components are placed to optimize data usage and resources.

   • Centralized Placement: Data is kept in one location.
   • Fragmented Placement: Data is divided and kept in different locations.
   • Replicated Placement: Multiple Copies of data are stored in different locations.

4. What are the Recovery Techniques used in RDBMS?
   Answer:

   • Deferred Update: Data is not updated immediately but is stored as a backup.
   • Shadow Paging: Data is stored in Shadow Pages and kept as a Backup.
   • Write-Ahead Logging (WAL): All updates are first stored in a Log and then applied to the database.

5. How does XML Query Processing work?
   Answer: In XML Query Processing, techniques like XPath, XQuery, and SQL/XML are used to extract necessary information from XML data.

Part C (3 × (7+7+6) = 20 marks)

J.K. Rowling
500

RDBMS Exam – Paper 3

Part A (10 × 1.5 = 15 marks)

1. What is Distributed Database Design, and why is it important?
2. Explain Encapsulation in Object-Oriented Modeling.
3. What are the challenges of Data Placement in DDBMS?
4. Define Temporal Databases and give an example.
5. What is Two-Phase Locking, and how does it help concurrency control?
6. Explain the role of External Sorting in Query Processing.
7. What is the importance of Multimedia Databases?
8. What is a Data Warehouse, and why is it needed?
9. Define Access Control in database security.
10. What is a Digital Signature, and how is it used in databases?

Part B (5 × 3 = 15 marks)

11. Explain the difference between Data Warehousing and Data Mining.
12. How does Query Optimization improve database performance?
13. What is Concurrency Control, and why is it necessary in DDBMS?
14. Explain the concept of Flow Control in Database Security.
15. What is the XML Tree Data Model, and how is it structured?

Part C (3 × (7+7+6) = 20 marks)

16. (a) Explain the placement of components in a Distributed Database System. (7)
    OR
    (b) Describe different types of attributes in Object-Oriented Modeling. (7)

17. (a) Discuss Transaction Recovery techniques in detail. (7)
    OR
    (b) Explain Classification Techniques in Data Mining with examples. (7)

18. (a) What is Public Key Cryptography, and how does it secure databases? (6)
    OR
    (b) Explain the concept of DTD Schema in XML with an example. (6)

RDBMS Exam – Paper 4

Part A (10 × 1.5 = 15 marks)

1. Define Generalization and Specialization in databases.
2. What is the purpose of Distributed Database Management Systems (DDBMS)?
3. What are the benefits of Data Warehousing?
4. Explain Serializability in Transactions.
5. What is Query Optimization, and why is it needed?
6. Explain the concept of a Multimedia Database.
7. What is the role of Encryption in database security?
8. Define Association Rule Mining in Data Mining.
9. What is a Query Execution Plan, and how is it created?
10. Explain the differences between SQL and XML Query Processing.

Part B (5 × 3 = 15 marks)

11. Describe Distributed Database System Architectures.
12. What is the importance of Transaction Management?
13. Explain the role of Data Communication in DDBMS.
14. What are Object and Set Operations in Query Processing?
15. Explain the key characteristics of a Data Warehouse.

Part C (3 × (7+7+6) = 20 marks)

16. (a) Explain the need and architecture of Data Warehousing. (7)
    OR
    (b) Describe the different types of Data Models in RDBMS. (7)

17. (a) Explain Temporal Database Concepts with an example. (7)
    OR
    (b) Discuss Security Specifications in SQL and their importance. (7)

18. (a) What is the role of Flow Control in Database Security? (6)
    OR
    (b) Explain how XML Schema is used in database systems. (6)

RDBMS Exam – Paper 5

Part A (10 × 1.5 = 15 marks)

1. Define Object-Oriented Database Models.
2. What is Inheritance, and how is it implemented in databases?
3. Explain Data Placement Strategies in DDBMS.
4. What is Two-Phase Locking, and how does it ensure consistency?
5. What is the importance of Query Processing Algorithms?
6. What are the key differences between Data Mining and Data Warehousing?
7. Explain how XML Queries work in database systems.
8. What is Cryptography, and why is it used in database security?
9. Explain the importance of Encryption Techniques in SQL Databases.
10. Define Heuristic Query Optimization and give an example.

Part B (5 × 3 = 15 marks)

11. Describe the types of Distributed Database System Architectures.
12. What is the impact of Concurrency Control on transactions?
13. Explain the need for Recovery Techniques in RDBMS.
14. Describe how Classification in Data Mining helps in decision-making.
15. What is a Digital Signature, and how does it ensure database security?

Part C (3 × (7+7+6) = 20 marks)

16. (a) Explain how Data Warehousing is different from Database Views. (7)
    OR
    (b) Describe the role of Public Key Infrastructure in database security. (7)

17. (a) Explain the need and applications of Temporal Databases. (7)
    OR
    (b) Discuss the impact of Query Optimization on database performance. (7)

18. (a) What is Flow Control in Databases, and how does it ensure security? (6)
    OR
    (b) Explain the importance of DTD Schema in XML Query Processing. (6)