Types and methods of data transmission (3)
Resources |
Revision Questions |
Computer Science
Login to see all questions
Click on a question to view the answer
1.
Question 3
A company needs to track employee attendance. They need to record each employee's clock-in and clock-out times. The data is relatively simple and doesn't require complex relationships. Which method would be most suitable for storing this information? Explain your choice, considering the advantages and disadvantages of each method.
- Relational Database
- Flat File
- Hierarchical Database
- Object-Oriented Database
The most suitable method for storing employee attendance information is a Flat File. Here's why:
- Advantages:
- Simplicity: Flat files are easy to implement and understand. We can store each employee's attendance record in a single line of the file.
- Efficiency: For a relatively simple data structure like this, flat files are very efficient to read and write.
- Low Overhead: Flat files require minimal overhead in terms of system resources.
- Suitable for Simple Data: When the data is simple and doesn't require complex relationships, a flat file is a good choice.
- Disadvantages:
- Data Redundancy: If an employee's information changes (e.g., address), it needs to be updated in multiple records.
- Data Integrity: Flat files do not enforce data integrity. There is no way to ensure that the data is accurate or consistent.
- Searching: Searching for specific attendance records can be inefficient, as it requires reading the entire file.
- Scalability: Flat files are not scalable. As the number of employees grows, the file can become very large and difficult to manage.
Why other options are less suitable:
- Relational Database: A relational database is overkill for this simple scenario. It would require setting up a database schema and managing SQL queries, which is unnecessary.
- Hierarchical Database: Hierarchical databases are not suitable for this type of data, as the relationships between employees and their attendance records are not hierarchical.
- Object-Oriented Database: Object-oriented databases are also overkill for this simple scenario. They are more complex to implement and manage than a flat file.
2.
Question 2
A game developer needs to store information about game levels (e.g., layout, enemies, items). The game levels are complex and involve many different objects with various properties. Which method would be most suitable for storing this information? Explain your choice, considering the advantages and disadvantages of each method.
- Relational Database
- Flat File
- Hierarchical Database
- Object-Oriented Database
The most suitable method for storing game level information is an Object-Oriented Database. Here's why:
- Advantages:
- Data Modeling: Object-oriented databases allow for a natural mapping of game objects (levels, enemies, items) to objects in the database. Each object can have properties (e.g., position, health, type) and methods (e.g., move, attack).
- Complex Relationships: Object-oriented databases can easily represent complex relationships between game objects. For example, an enemy might be located within a specific level.
- Code Reusability: Object-oriented principles like inheritance allow for code reusability. We can create base classes for game objects and derive specialized classes for different types of objects.
- Flexibility: Object-oriented databases are more flexible than relational databases when dealing with evolving data models. We can easily add new properties or methods to game objects without modifying the entire database schema.
- Performance: Object-oriented databases can provide better performance for complex queries involving object relationships.
- Disadvantages:
- Complexity: Setting up and managing an object-oriented database can be more complex than a relational database.
- Maturity: Object-oriented databases are less mature than relational databases, and there are fewer tools and resources available.
Why other options are less suitable:
- Relational Database: While a relational database *could* be used, it would require a complex schema with many tables to represent the game objects and their relationships. This would be less flexible and more difficult to manage than an object-oriented approach.
- Flat File: Flat files are not suitable for representing complex data structures like game levels. They would be difficult to maintain and query.
- Hierarchical Database: Hierarchical databases are not well-suited for representing the complex relationships between game objects. They are also less flexible than object-oriented databases.
3.
Explain the function of the header and trailer in a data packet. Provide examples of information typically found within each.
The header of a data packet is essential for network routing and control. It contains information that allows network devices (like routers) to understand where the packet is coming from and where it needs to go. Typical information in the header includes:
- Source IP Address: Identifies the sender of the packet.
- Destination IP Address: Identifies the intended recipient.
- Protocol (e.g., TCP, UDP): Specifies the protocol used for communication.
- Sequence Number (TCP): Helps in reassembling data in the correct order.
- Checksum: Used for error detection during transmission.
The trailer primarily focuses on error detection. It typically contains a Cyclic Redundancy Check (CRC). A CRC is a mathematical calculation performed on the packet data that generates a checksum value. The receiver performs the same calculation and compares the generated checksum with the checksum in the trailer. If they don't match, it indicates that errors occurred during transmission, and the packet may be discarded or retransmitted.