Hexaware Technologies Power BI Developer Interview Questions and Answers for Experienced

Star schema has a single fact table connected to multiple dimension tables, while snowflake schema has normalized dimension tables.

• Star schema denormalizes dimension tables, making it easier to query but potentially less efficient for storage.

• Snowflake schema normalizes dimension tables, reducing redundancy but potentially making queries more complex.

• Star schema is commonly used for data warehouses with denormalized da...read more

The GROUP BY clause is used in SQL to group rows that have the same values into summary rows.

• It is used with aggregate functions like COUNT, SUM, AVG, etc.

• It helps in summarizing data and generating reports.

• It is often used in conjunction with the HAVING clause to filter grouped data.

• Example: SELECT department, COUNT(employee_id) FROM employees GROUP BY department;