DataBase Engineer - DBA

Oracle

You are given an m x n grid where each cell can have one of three values: 0 representing an empty cell, 1 representing a fresh orange, or 2 representing a rotten orange. Every minute, any fresh orange that is 4-directionally adjacent to a rotten orange becomes rotten. Return the minimum number of minutes that must elapse until no cell has a fresh orange. If it is impossible, return -1. For example, consider the following grid: [[2,1,1], [1,1,0], [0,1,1]] In this case, the function should return 4 because it takes 4 minutes for all the fresh oranges to rot. As another example, consider the following grid: [[2,1,1], [0,1,1], [1,0,1]] In this case, the function should return -1 because the orange in the bottom left will never rot. Here's how the rotting process would proceed in the first example: Initial state: [[2,1,1], [1,1,0], [0,1,1]] After 1 minute: [[2,2,1], [2,1,0], [0,1,1]] After 2 minutes: [[2,2,2], [2,2,0], [0,1,1]] After 3 minutes: [[2,2,2], [2,2,0], [0,2,1]] After 4 minutes: [[2,2,2], [2,2,0], [0,2,2]] All fresh oranges are now rotten after 4 minutes. Write a function to solve this problem efficiently. Consider edge cases such as an empty grid or a grid with no fresh oranges initially.

Oracle

Let's design a URL shortening service like bit.ly. Consider the following: Functional Requirements: The service should accept a long URL and generate a unique short URL. Users should be able to access the original URL by visiting the shortened URL. The service should track click statistics for each shortened URL. Non-Functional Requirements: The service should be highly available and scalable to handle a large number of URL shortening and redirection requests. Shortened URLs should be generated quickly. The system should be fault-tolerant. Considerations: How would you handle URL collisions (when the same short URL is generated for different long URLs)? How would you design the data storage? How would you optimize the system for read-heavy traffic (redirections)? How would you implement analytics and track clicks? Explain the architectural components, data model, algorithms, and scaling strategies you would use to build such a system. Provide specific examples for URL encoding and decoding. For example, how would you encode https://www.example.com/very/long/url/path into something like bit.ly/xyz123?

Oracle

Let's discuss your strengths and weaknesses. Could you provide specific examples that highlight both your key strengths and areas where you are actively working to improve? Think about situations where your strengths significantly contributed to a positive outcome, and conversely, instances where your weaknesses presented a challenge. For instance, perhaps you excel at quickly learning new technologies, as demonstrated by your successful implementation of a novel machine learning algorithm for a recent project, resulting in a 15% performance improvement. On the other hand, you might find public speaking challenging, and you are addressing this by joining a Toastmasters club and practicing presentations regularly. Providing concrete examples like these will give me a better understanding of your capabilities and your commitment to continuous self-improvement.