CMS IT Services Oracle Database Administrator Interview Questions and Answers

Hashtable is synchronized while hashmap is not.

• Hashtable is thread-safe while hashmap is not.

• Hashtable does not allow null keys or values while hashmap allows one null key and multiple null values.

• Hashtable is slower than hashmap due to synchronization.

• Hashtable is a legacy class while hashmap is a newer implementation.

Hashmap is not thread-safe while Concurrent Hashmap is thread-safe.

• Hashmap is not suitable for multi-threaded environments as it can lead to race conditions and data inconsistencies.

• Concurrent Hashmap allows multiple threads to access and modify the map concurrently without any data inconsistencies.

• Concurrent Hashmap uses a technique called lock striping to achieve thread-safety.

• Concurrent Hashmap is slower than Hashma...read more

To compile all Java files inside a folder using Cmd, navigate to the folder and run 'javac *.java'

• Open Command Prompt and navigate to the folder containing the Java files

• Run the command 'javac *.java' to compile all Java files in the folder

• Check for any errors or warnings in the output

Hashmap is a data structure that stores key-value pairs. Concurrent Hashmap is a thread-safe version of Hashmap.

• Hashmap uses hashing to store and retrieve elements based on their keys.

• Concurrent Hashmap allows multiple threads to access and modify the map concurrently.

• Hashmap has a load factor that determines when the map needs to be resized.

• Concurrent Hashmap uses a technique called lock striping to allow concurrent a...read more

Deadlock is a situation where two or more processes are unable to proceed because each is waiting for the other to release a resource.

• Deadlock occurs when two or more processes are stuck in a circular wait, where each process is waiting for a resource held by another process.

• Four necessary conditions for deadlock are mutual exclusion, hold and wait, no preemption, and circular wait.

• Example: Process A holds resource X a...read more

I have experience with various technologies including Java, Python, HTML/CSS, JavaScript, and SQL.

• Java

• Python

• HTML/CSS

• JavaScript

• SQL

I am looking for a change to explore new opportunities and challenges. My notice period is 30 days.

• Seeking new opportunities and challenges

• Want to learn and grow in a different environment

• Exploring better career prospects

• Seeking a company with a better work-life balance

• Notice period is 30 days

I am proficient in Java, Python, and C++. I have 2 years of experience in software development. I have excellent communication skills for client interaction.

• Proficient in Java, Python, and C++

• 2 years of software development experience

• Excellent communication skills for client interaction

To find the shortest path in a graph stored in SQL, use algorithms like Dijkstra's or A* with SQL queries for traversal.

• Use Dijkstra's algorithm for weighted graphs to find the shortest path efficiently.

• For unweighted graphs, consider using Breadth-First Search (BFS).

• Store graph edges in a table with columns for source, destination, and weight.

• Example SQL query: SELECT * FROM edges WHERE source = 'A' AND destination = ...read more