What are the different types of NoSQL databases, and how do they differ from each other?

  • Document-oriented, Key-value, Columnar, Graph
  • In-memory, Cache-based, Distributed, Indexed
  • Relational, Hierarchical, Wide-column, Time-series
  • Tabular, Spatial, Structured, Semi-structured
NoSQL databases come in various types, each designed for specific data handling needs. Document-oriented databases like MongoDB store data in flexible, JSON-like documents, while key-value stores like Redis use simple key-value pairs. Columnar databases such as Cassandra organize data in columns rather than rows. Graph databases like Neo4j focus on relationships between data entities. Understanding these differences helps in choosing the right database for specific use cases.

In a scenario where a website's DNS records are incorrect, causing it to be unreachable, how would you troubleshoot and resolve this issue?

  • Check DNS configuration on the server
  • Flush DNS cache on client
  • Test connectivity using nslookup
  • Update DNS records with correct information
Updating DNS records with the correct information is crucial for resolving DNS-related issues that make a website unreachable. This involves accessing the domain registrar or DNS provider's control panel and ensuring that the DNS records (such as A records, CNAME records) are correctly configured to point to the website's hosting server. Checking the DNS configuration on the server helps identify any misconfigurations or discrepancies. Flushing the DNS cache on the client can resolve cached DNS issues but doesn't address incorrect DNS records directly. Testing connectivity using nslookup is a diagnostic step to verify DNS resolution, but it alone does not fix the incorrect records.

You're tasked with ensuring secure file transfers within your organization. Which protocol(s) would you recommend and why?

  • AS2 (Applicability Statement 2)
  • FTPS (File Transfer Protocol Secure)
  • HTTPS (Hypertext Transfer Protocol Secure)
  • SFTP (SSH File Transfer Protocol)
SFTP (SSH File Transfer Protocol) is recommended for secure file transfers because it encrypts both authentication information and data being transferred. This ensures that sensitive files are protected from unauthorized access during transmission. FTPS also provides secure file transfer, but it requires additional configurations such as SSL certificates, making it more complex to set up and maintain compared to SFTP. HTTPS is primarily used for secure web communications, not file transfers. AS2 is a protocol specifically designed for secure and reliable data interchange over the Internet, but it may not be as commonly implemented as SFTP for general file transfers within an organization.

What is the main advantage of using NoSQL databases over traditional relational databases?

  • ACID Compliance
  • Data Consistency
  • Scalability
  • Schema Flexibility
NoSQL databases offer schema flexibility, allowing developers to store and manage unstructured or semi-structured data without predefined schemas. This flexibility is advantageous in scenarios where the data model is evolving or where dealing with highly variable data types. Unlike traditional relational databases that enforce a strict schema, NoSQL databases can adapt to changing data requirements, making them more scalable and agile in certain use cases.

The ________ layer of the OSI Model is concerned with establishing, maintaining, and terminating sessions between devices.

  • Data Link
  • Network
  • Session
  • Transport
The Session layer manages session establishment, maintenance, and termination to enable communication between devices in a network.

You're developing a scheduling algorithm for a project with time constraints. How would you apply dynamic programming to optimize the schedule?

  • Apply a random search algorithm to explore different scheduling options and select the one with the lowest total duration.
  • Implement a greedy algorithm that prioritizes tasks based on their deadlines and durations to optimize the schedule.
  • Use a brute-force approach to generate all possible schedules and select the one with the least number of conflicts.
  • Utilize dynamic programming to break down the scheduling problem into smaller subproblems and store the solutions to these subproblems in a table for efficient retrieval and reuse.
Dynamic programming involves breaking down a complex problem into smaller subproblems, solving each subproblem only once, and storing the solutions to avoid redundant computations. In scheduling, this can be applied by defining the optimal schedule for smaller time intervals and then combining them to obtain the overall optimal schedule. It optimizes the schedule by considering dependencies, resource availability, and time constraints effectively.

The process of one thread waiting for another thread to finish its execution is known as ___________.

  • Blocking
  • Suspension
  • Synchronization
  • Threading
When one thread waits for another to complete its execution, it's termed synchronization. This can involve mechanisms like joining threads or using synchronization primitives like mutexes or semaphores. Suspension refers to temporarily halting a thread's execution, threading is a general term for working with threads, and blocking describes a state where a thread is waiting for an event or resource to become available.

In React, ___________ is used to manage component-level state.

  • Redux
  • useState
  • Context API
  • Lifecycle Methods
useState is a React hook that allows functional components to manage state locally. It simplifies state management within a component without the need for class-based components or external libraries like Redux. The other options are also valid for state management, but useState is specifically designed for component-level state management and is a fundamental part of React's modern approach to state handling.

Which type of redundancy does database normalization aim to eliminate?

  • Data Redundancy
  • Functional Redundancy
  • Indexing Redundancy
  • Structural Redundancy
Database normalization aims to eliminate Functional Redundancy, where the same piece of data is stored in multiple places, leading to inconsistencies and potential data integrity issues.

Which operation in queues removes an element from the front?

  • Dequeue
  • Enqueue
  • Peek
  • Push
The operation in queues that removes an element from the front is called dequeue. Dequeue removes the element that has been in the queue the longest, following the First In, First Out (FIFO) principle. This operation is essential for processing data in the order it was received, such as handling tasks in a computer's task queue or managing requests in a web server's request queue.

___________ is a popular React feature that enables seamless integration with existing JavaScript codebases.

  • Babel
  • JSX
  • TypeScript
  • Webpack
JSX (JavaScript XML) is a syntax extension used in React for writing HTML-like code within JavaScript. It allows developers to create React components more elegantly and expressively. While TypeScript, Webpack, and Babel are all crucial tools in the React ecosystem, JSX stands out as the correct answer because it directly relates to React's unique approach to building user interfaces with a blend of JavaScript and HTML-like syntax.

The ___________ time is the maximum amount of time a process can execute before being interrupted in preemptive scheduling.

  • Arrival
  • Burst
  • Quantum
  • Response
The quantum time, also known as time slice or time quantum, is the maximum amount of time a process can execute before being interrupted in preemptive scheduling algorithms like Round Robin. It defines the length of each time slot during which a process can run before the scheduler switches to another process.