The Sleep Company Interview Questions and Answers

AS is used to assign an alias to a column or table in SQL, while IS is used to compare values or check for null values.

• AS is used in SELECT statements to assign a temporary name to a column or table

• AS can also be used in JOIN statements to assign aliases to tables

• IS is used in WHERE clauses to compare values or check for null values

• IS NULL is used to check if a value is null

• IS NOT NULL is used to check if a value is not null

Designing an APIGateway and 3 Microservices involves defining endpoints, communication protocols, and service interactions.

• Define the endpoints for the APIGateway to route requests to the appropriate microservices.

• Choose communication protocols such as REST or gRPC for interactions between services.

• Implement service discovery and load balancing for efficient communication.

• Ensure security measures like authentication and authorization are in place.

• Use tools like Swagger for AP...read more

Implemented Singleton design pattern in a project to ensure only one instance of a class is created.

• Used a private constructor to prevent instantiation of the class from outside.

• Created a static method to provide a single point of access to the instance.

• Stored the single instance as a private static variable within the class.

• Ensured thread safety by using synchronized keyword or double-checked locking.

WITH clause is used to define a temporary result set that can be used in a subsequent SQL statement.

• WITH clause is also known as Common Table Expression (CTE)

• It improves the readability and maintainability of complex SQL queries

• It can be used to simplify complex queries by breaking them down into smaller, more manageable parts

• It can be used to create recursive queries

• Example: WITH sales AS (SELECT * FROM sales_data) SELECT * FROM sales WHERE amount > 1000;

• Example: WITH recurs...read more

Case condition is used to perform conditional logic in SQL queries.

• It allows for conditional statements in SELECT, WHERE, and ORDER BY clauses.

• Syntax: CASE WHEN condition THEN result ELSE alternative END

• Can be nested for complex logic

• Useful for data transformation and reporting

NTILE is a SQL function used to divide a result set into a specified number of groups.

• NTILE requires an integer argument that specifies the number of groups to divide the result set into.

• It assigns a group number to each row in the result set based on the specified number of groups.

• NTILE is often used in conjunction with the ORDER BY clause to divide the result set based on a specific column.

• NTILE can be used to calculate percentiles by dividing the result set into 100 groups...read more

Network teaming can be checked using tools like ethtool, nmcli, and ifconfig.

• Use ethtool to check the status of network interfaces and teaming configuration

• Use nmcli to view and manage network teaming settings

• Check the output of ifconfig to verify the network teaming configuration