ThoughtWorks Data Engineer Interview Questions and Answers

Normalization is a process of organizing data in a database to reduce redundancy and improve data integrity.

• Normalization involves breaking down a table into smaller tables and establishing relationships between them.

• There are different levels of normalization, with each level having specific rules to follow.

• Normalization helps to prevent data inconsistencies and anomalies.

• Examples of normalization include converting r...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