Iris Software Data Engineer 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

CTE and temp tables are used to store intermediate results in SQL queries.

• CTE stands for Common Table Expression and is defined within a query.

• Temp tables are created in the tempdb database and can be accessed across sessions.

• CTEs are generally faster and more readable than temp tables.

• Temp tables are useful for complex queries with multiple steps or when data needs to be manipulated.

• CTEs are useful for recursive queri

Asynchronous programming in .NET allows for non-blocking execution of code, improving performance and responsiveness.

• Async and Await keywords used to implement asynchronous programming

• Allows for parallel execution of multiple tasks

• Improves performance and responsiveness of applications

• Examples include web applications, file I/O operations, and database queries

Threading in .NET allows for concurrent execution of code, improving performance and responsiveness.

• Threading allows for multiple threads of execution to run concurrently

• Thread class is used to create and manage threads

• Thread synchronization is important to prevent race conditions and deadlocks

• Async/await is a newer approach to concurrency in .NET

• TPL (Task Parallel Library) provides higher-level abstractions for concur

Performance tuning of SQL stored procedure involves optimizing query execution time and reducing resource usage.

• Identify and optimize the most resource-intensive queries

• Use appropriate indexing and partitioning techniques

• Minimize network round trips and data transfers

• Avoid using cursors and temporary tables

• Use query hints and plan guides to influence query execution plan

• Regularly monitor and analyze query performance u...read more