Amazon Business Analyst Interview Questions and Answers

There are 303 prime numbers between 0 and 2000, including 2, 3, 5, and 1999.

• A prime number is a natural number greater than 1 that cannot be formed by multiplying two smaller natural numbers.

• The first few prime numbers are 2, 3, 5, 7, 11, 13, 17, 19, 23, and 29.

• The largest prime number less than 2000 is 1999.

• To find prime numbers, one can use methods like the Sieve of Eratosthenes.

SQL's GROUP BY clause aggregates data based on specified columns, enabling summary statistics and insights.

• GROUP BY is used to arrange identical data into groups.

• Example: SELECT department, COUNT(*) FROM employees GROUP BY department; - counts employees per department.

• You can use aggregate functions like SUM, AVG, MAX, MIN with GROUP BY.

• Example: SELECT department, AVG(salary) FROM employees GROUP BY department; - ...read more

Using Window Function, Date and Time in a complex SQL query

• Use ROW_NUMBER() to assign a unique number to each row within a partition

• Use PARTITION BY to divide the result set into partitions

• Use ORDER BY to specify the order of rows within each partition

• Utilize functions like LAG(), LEAD(), SUM(), AVG(), etc. within the window frame

Utilized STAR methodology to address a project involving data analysis for improving customer satisfaction.

• Situation: Faced declining customer satisfaction scores in Q1.

• Task: Analyze customer feedback data to identify key pain points.

• Action: Conducted surveys and interviews, then used data visualization tools to present findings.

• Result: Implemented changes based on insights, leading to a 20% increase in satisfacti...read more

SQL window functions allow for advanced data analysis by performing calculations across a set of table rows related to the current row.

• Window functions operate on a set of rows defined by an OVER() clause.

• Common window functions include ROW_NUMBER(), RANK(), DENSE_RANK(), SUM(), AVG(), etc.

• Example: SELECT employee_id, salary, RANK() OVER (ORDER BY salary DESC) AS salary_rank FROM employees;

• Window functions can be ...read more

I rate myself as proficient in SQL with experience in writing complex queries and optimizing database performance.

• Proficient in writing complex SQL queries

• Experience in optimizing database performance

• Familiar with database management systems like MySQL, SQL Server, Oracle

• Ability to work with large datasets and perform data analysis

• Knowledge of SQL functions, joins, subqueries, and indexes

Merging queries involves combining data from multiple sources to create a unified result set.

• Use SQL JOINs (INNER, LEFT, RIGHT) to combine tables based on a common key. Example: SELECT * FROM Orders INNER JOIN Customers ON Orders.CustomerID = Customers.CustomerID.

• Utilize UNION to combine results from two or more SELECT statements. Example: SELECT City FROM Customers UNION SELECT City FROM Suppliers.

• Consider using ...read more