RWS Group Power BI Developer Interview Questions and Answers

Common data connectivity modes include DirectQuery, Import, Live Connection, and Composite models.

• DirectQuery allows querying data directly from the data source in real-time.

• Import mode imports data into Power BI for faster performance but may not reflect real-time data.

• Live Connection connects Power BI to a data source without importing data.

• Composite models combine DirectQuery and Import modes for flexibility.

Power BI components include Power Query, Power Pivot, Power View, and Power Map.

• Power Query: Used for data extraction, transformation, and loading (ETL)

• Power Pivot: Used for data modeling and analysis

• Power View: Used for data visualization and interactive reports

• Power Map: Used for geospatial data visualization

Power Query is used for data transformation and Power View is used for data visualization in Power BI.

• Power Query is used to extract, transform, and load data from different sources.

• Power View is used to create interactive visualizations and reports based on the transformed data.

• Power Query is more focused on data preparation and cleaning, while Power View is focused on data visualization.

• Power Query can be used to mer...read more

Relationship cardinality defines the number of instances of one entity that can be associated with the number of instances of another entity.

• One-to-One: Each record in the first entity is associated with only one record in the second entity.

• One-to-Many: Each record in the first entity can be associated with multiple records in the second entity.

• Many-to-Many: Multiple records in the first entity can be associated with m

Having clause is used with aggregate functions while where clause is used to filter rows

• Having clause is used with GROUP BY to filter groups based on conditions

• Where clause is used to filter rows based on conditions

• Having clause is applied after grouping while where clause is applied before grouping

• Example: SELECT department, AVG(salary) FROM employees GROUP BY department HAVING AVG(salary) > 50000

• Example: SELECT * FRO

Use SQL query with ORDER BY and LIMIT to find the 4th highest salary

• Use ORDER BY clause to sort salaries in descending order

• Use LIMIT 3,1 to skip the first 3 highest salaries and get the 4th highest salary

RLS stands for Row-Level Security, a feature in Power BI that restricts data access based on user roles.

• RLS allows you to control which rows of data a user can access in a Power BI report or dashboard

• You can define security roles and rules to filter data based on user attributes or roles

• RLS helps in ensuring data privacy and compliance with regulations

• For example, you can use RLS to restrict a sales manager to only see

Use SUMX function in DAX to calculate total sales of a product

• Use SUMX function to iterate over each row in the sales table

• Filter the table to include only the specific product

• Sum up the sales amount for each row to get the total sales

CI-CD pipeline best practices ensure faster and reliable software delivery.

• Automate the entire pipeline

• Use version control for code and configuration

• Perform continuous testing and integration

• Ensure security and compliance

• Monitor and measure performance

• Implement feedback loops for continuous improvement