Phenom Product Development Engineer Interview Questions and Answers

DBMS locking is a mechanism to manage concurrent access to data in a database to prevent data corruption.

• Locking is used to ensure data integrity and consistency in a multi-user environment.

• Types of locks include shared locks, exclusive locks, and update locks.

• Example scenario: Two users trying to update the same record simultaneously - one user gets an exclusive lock while the other waits.

• Deadlocks can occur when...read more

LRU cache program is a data structure that stores the most recently used items.

• LRU cache is typically implemented using a doubly linked list and a hashmap.

• When a new item is accessed, it is moved to the front of the list.

• If the cache is full, the least recently used item is removed from the end of the list.

• Example: If the cache has a capacity of 3 and items A, B, C are accessed in that order, the cache will store ...read more

To swap numbers without using a third variable, use arithmetic operations.

• Add the two numbers to get the first number

• Subtract the second number from the sum to get the second number

• Subtract the original first number from the sum to get the original second number

Async and threading offer advantages in improving performance and responsiveness in software development.

• Async allows for non-blocking operations, improving responsiveness by allowing other tasks to continue while waiting for a response.

• Threading enables parallel execution of tasks, utilizing multiple CPU cores to improve performance.

• Async is more suitable for I/O-bound operations, while threading is better for CP...read more

Global Interpreter Lock (GIL) is a mutex that protects access to Python objects, preventing multiple threads from executing Python bytecodes simultaneously.

• GIL is a mechanism used in CPython to ensure that only one thread executes Python bytecode at a time.

• It prevents multiple threads from executing Python code concurrently, which can cause issues with thread safety.

• GIL can impact the performance of multi-threaded...read more

Given an array of integers, return indices of the two numbers such that they add up to a specific target.

• Use a hashmap to store the difference between the target and each element as keys and their indices as values.

• Iterate through the array and check if the current element's complement exists in the hashmap.

• Return the indices of the two numbers that add up to the target.

A queue can be implemented using arrays or linked lists. It follows the FIFO principle.

• Create an empty array or linked list

• Enqueue elements at the end of the queue

• Dequeue elements from the front of the queue

• Implement methods like isEmpty, isFull, peek, etc.

• Example: Queue implemented using an array - https://www.geeksforgeeks.org/queue-set-1introduction-and-array-implementation/

Use two pointers to swap 0s to the beginning and 2s to the end while keeping 1s in the middle.

• Initialize two pointers, one for 0s (left) and one for 2s (right).

• Iterate through the array and swap 0s to the left pointer and 2s to the right pointer.

• Example: Input array = ['2', '1', '0', '2', '1', '0'], Output array = ['0', '0', '1', '1', '2', '2']