Power BI Interview Questions and Answers
1. What is filled formatting, and when is it applied?
Ans: Filled formatting is used to adjust the fill color in visuals like maps, highlighting regions or areas based on a value. For example, in a sales dashboard, regions with higher sales can be shaded darker than regions with lower sales.
3. What are the relationship types in Power BI, and how do you avoid many-to-many?
Ans: Power BI supports one-to-one, one-to-many, and many-to-many relationships. To avoid many-to-many, introduce a bridge table or remove duplicates to maintain a one-to-many relationship.
4. How do you handle missing or dirty data in Power BI?
Ans: Use Power Query for data cleansing—apply transformations like removing null values, filling missing values, or replacing errors.
5. What is Clustered Column Chart?
Ans: A Clustered Column Chart in Power BI displays data in vertical bars, grouping different categories side by side for easy comparison. Each bar represents a category, and the bars are placed next to each other, allowing you to compare multiple values across categories within the same axis.
For example, you can compare sales figures for different products across different regions in a single view.
6. Difference between Pie Chart and Donut Chart in Power BI?
Ans: Both charts show parts of a whole. A pie chart is fully filled, while a donut chart has a hole in the center, often used to display total values.
7. Can you explain measures and text functions used in your projects?
Ans: Measures: Used for dynamic calculations like total sales, average revenue.
Text Functions: Examples include CONCATENATE for combining fields,
LEFT/RIGHT for extracting text, Replace, Trim, Search etc.
8. Power BI Licenses and Paginated Reports?
Ans: Worked with Power BI Pro for collaboration and Power BI Premium for handling large datasets.
Paginated reports offer pixel-perfect formatting, typically for printing or exporting.
9. How do you troubleshoot performance issues in Power BI reports?
Ans: Techniques include optimizing data models, using fewer visuals, reducing the number of columns in datasets, and enabling Aggregations for large datasets.
10. What types of filters are available in Power BI, and how do they impact data analysis?
Ans: Filters include visual-level, page-level, report-level, and drill through filters. Filters refine data shown in visuals, providing more control over the insights.
11. Can you explain bookmarks and their use cases in Power BI?
Ans: Bookmarks save the state of a report, useful for creating interactive reports, navigation between views, or highlighting specific insights in presentations.
12. How do you manage large datasets in Power BI?
Ans: Implement strategies like data aggregation, query folding, and incremental refresh to optimize performance.
Goldman Sachs data analyst interview experience(2+year)
SQL
1 -find avg of salaries department wise from table
2 -Write a SQL query to see employee name and manager name using a self-join on ’employees’ table with columns ’emp_id’, ‘name’, and ‘manager_id’.
3 -newest joinee for every department (solved using lead lag)
4-Write a query to find the nth highest salary from a table Employees with columns EmployeeID, Name, and Salary.
POWER BI
1. What does Filter context in DAX mean?
2. Explain how to implement Row-Level Security (RLS) in Power BI.
3. Describe different types of filters in Power BI.
4. Explain the difference between ‘ALL’ and ‘ALLSELECTED’ in DAX.
5. How do you calculate the total sales for a specific product using DAX?
PYTHON
1. Create a dictionary, add elements to it, modify an element, and then print the dictionary in alphabetical order of keys.
2. Find unique values in a list of assorted numbers and print the count of how many times each value is repeated.
3. Find and print duplicate values in a list of assorted numbers, along with the number of times each value is repeated.
