Which normal form allows multi-valued dependencies to be removed?
- First Normal Form (1NF)
- Fourth Normal Form (4NF)
- Second Normal Form (2NF)
- Third Normal Form (3NF)
Fourth Normal Form (4NF) is the normal form that allows multi-valued dependencies to be removed. 4NF is an extension of third normal form (3NF) and deals specifically with situations where there are multiple independent multi-valued dependencies between attributes. By decomposing the table into smaller tables and ensuring each table has a single theme, 4NF helps in removing such complex dependencies and reducing data redundancy.
Which data structure is typically used for binary search?
- Array
- Linked List
- Sorted Array
- Stack
Binary search is typically performed on a sorted array. The reason for this is that binary search requires the elements to be in sorted order to efficiently divide and conquer the search space, reducing the time complexity to O(log n) compared to O(n) for linear search in an unsorted array.
In CSS, the ___________ property is used to control the appearance of text decorations such as underline and overline.
- font-style
- font-variant
- text-decoration
- text-transform
The text-decoration property in CSS is used to control the appearance of text decorations such as underline, overline, line-through, and blink. This property is commonly used to style links and text decorations.
The ________ layer of virtualization abstracts physical hardware resources for efficient utilization.
- Hypervisor
- Container
- Application
- Hardware
The correct option is "Hypervisor." The hypervisor layer is responsible for abstracting physical hardware resources such as CPU, memory, and storage, allowing multiple virtual machines (VMs) to share the underlying physical resources efficiently. This abstraction enables better resource utilization and flexibility in managing virtualized environments.
Memory ___________ is a technique used to rearrange memory contents to place all free memory together.
- Allocation
- Compaction
- Fragmentation
- Paging
Memory compaction is a technique used in memory management to reduce fragmentation by rearranging memory contents to place all free memory together in contiguous blocks. This helps in maximizing the available memory for allocating new processes or data structures, especially in systems where memory fragmentation can lead to inefficient memory usage.
Explain the concept of spanning tree protocol (STP) and its role in preventing network loops.
- STP elects a root bridge to serve as a reference point for path calculations and topology stability.
- STP operates at Layer 3 of the OSI model and prioritizes traffic based on VLAN configurations.
- STP uses BPDU messages to exchange information between switches and determine the best path to the root bridge.
- Spanning Tree Protocol (STP) prevents network loops by blocking redundant paths in a switched network.
STP is vital for ensuring network stability and preventing broadcast storms caused by looping paths in Ethernet networks. By intelligently blocking redundant links while maintaining alternative paths, STP maintains a loop-free topology, optimizing network performance and reliability.
In your role as a security analyst, you discover a vulnerability in a web application that allows attackers to execute arbitrary SQL queries. How would you advise the development team to remediate this vulnerability?
- Use parameterized queries or prepared statements to sanitize user input and prevent SQL injection attacks.
- Implement strict input validation on user inputs, perform regular security audits and code reviews.
- Utilize a web application firewall (WAF) to block malicious SQL queries, restrict database permissions to minimize attack surface.
- Educate developers on secure coding practices, use stored procedures to encapsulate database operations.
Option 1 suggests using parameterized queries or prepared statements, which are fundamental to preventing SQL injection attacks by separating user input from SQL commands. Option 3 involves additional security measures like WAF and database permissions, which are beneficial but secondary to fixing the core vulnerability. Option 4 addresses secure coding practices but does not focus specifically on remedying SQL injection vulnerabilities.
Dynamic programming is often used to solve problems related to ___________ optimization.
- Cost
- Resource
- Space
- Time
Dynamic programming is commonly used for resource optimization problems, where the goal is to optimize the allocation of resources such as time, money, or personnel to achieve the best possible outcome. This technique involves breaking down the optimization problem into smaller subproblems and using optimal substructure to find the overall optimal solution.
What is the purpose of a file system in an operating system?
- To control the hardware resources of a computer
- To maintain system logs and error messages
- To manage user permissions and access control
- To organize and manage files and directories efficiently
A file system in an operating system primarily serves to organize and manage files and directories efficiently, enabling users and applications to store, retrieve, and manipulate data effectively. This organization includes managing file metadata such as permissions, timestamps, and file locations. The file system also ensures data integrity and reliability through mechanisms like journaling and redundancy. Overall, it provides a structured approach to data storage and retrieval within an operating system.
The ___________ scheduling algorithm selects the process with the shortest burst time.
- First Come First Serve
- Priority
- Round Robin
- Shortest Job First
Shortest Job First (SJF) scheduling algorithm selects the process with the shortest burst time to execute next. This minimizes the average waiting time and improves system throughput by prioritizing smaller jobs. SJF can be either preemptive or non-preemptive, where in preemptive SJF, a new job with a shorter burst time can interrupt the currently running job.