Tableau vs Power BI comparison - Practice Questions

Challenge - 5 Problems

🧠 Conceptual

intermediate

Key Difference in Data Connectivity

Which statement best describes a key difference in how Tableau and Power BI connect to data sources?

A Tableau primarily uses live connections and requires manual refresh for extracts, while Power BI uses scheduled refreshes for both live and imported data.

B Power BI requires manual refresh of data extracts, while Tableau automatically refreshes all data sources.

C Tableau cannot connect to cloud data sources, but Power BI can connect to both cloud and on-premises sources.

D Power BI only supports live connections, whereas Tableau only supports imported data extracts.

💡 Hint

Think about how each tool handles live data versus imported data.

Tableau supports live connections and extracts that require manual refresh. Power BI supports both live connections and imported data with scheduled refreshes.

❓ visualization

intermediate

Choosing the Best Visualization Tool for Interactive Dashboards

You want to create highly interactive dashboards with custom visualizations and advanced analytics. Which tool is generally better suited for this purpose?

A Power BI, because it has more built-in AI visuals and integrates deeply with Microsoft services.

B Tableau, because it offers more flexibility in custom visualizations and advanced analytics features.

C Power BI, because it supports more data sources than Tableau.

D Tableau, because it is free and open source.

💡 Hint

Consider which tool is known for flexibility and advanced visual options.

Tableau is known for its flexibility and advanced analytics capabilities, making it better for highly interactive and custom dashboards.

❓ dax_lod_result

advanced

DAX Measure Calculation in Power BI

Given a sales table with columns: Product, Region, and SalesAmount, what is the result of this DAX measure?

Sales by Region = CALCULATE(SUM(Sales[SalesAmount]), ALLEXCEPT(Sales, Sales[Region]))

If the sales data is:

• Product A, Region East, 100
• Product B, Region East, 150
• Product A, Region West, 200

What is the value of Sales by Region for Product A in Region East?

A 450

B 100

C 150

D 250

💡 Hint

ALLEXCEPT removes filters except for Region, so sum sales for all products in the same region.

The measure sums sales for all products in the same region. For Region East, total sales are 100 + 150 = 250.

❓ data_modeling

advanced

Handling Many-to-Many Relationships

In Power BI, you have two tables: Customers and Products. Customers can buy multiple products, and products can be bought by multiple customers. What is the best way to model this many-to-many relationship?

A Create a bridge table (fact table) that contains CustomerID and ProductID to link the two tables.

B Create a direct one-to-one relationship between Customers and Products tables.

C Merge Customers and Products tables into one table to avoid relationships.

D Use a calculated column in Customers to list all products bought.

💡 Hint

Think about how to represent many-to-many relationships in relational models.

A bridge table with CustomerID and ProductID allows modeling many-to-many relationships properly.

🎯 Scenario

expert

Optimizing Dashboard Performance with Large Data

You have a Power BI dashboard connected to a large dataset with millions of rows. Users report slow loading times. Which approach will most effectively improve performance?

A Add more visuals to the dashboard to distribute the load evenly.

B Disable all filters and slicers to speed up rendering.

C Import data and create aggregated tables to reduce the amount of data processed in visuals.

D Use DirectQuery mode to query data live without importing, reducing memory usage.

💡 Hint

Think about reducing data volume processed by visuals.

Importing data with aggregated tables reduces data volume and speeds up dashboard performance compared to live queries.