Power BI Interview Questions (2026): 22 Questions With Answers

Last updated: 13 October 2026 · By the Asuraa Team

Quick answer: Power BI interviews for freshers test Power Query cleaning, star schema modelling, DAX and publishing with row-level security. Expect to explain measures vs calculated columns, write CALCULATE, SUMX and year-over-year measures, and compare storage modes. Microsoft Learn documents that Import allows up to 8 scheduled refreshes a day on Pro and 48 on Premium, and that RLS applies only to workspace Viewers.

Key takeaways

• Microsoft's star schema guidance treats the one side of a one-to-many relationship as the dimension and the many side as the fact table.
• Microsoft Learn lists up to 8 scheduled refreshes a day for Import models on Pro and up to 48 on Premium or Premium Per User.
• DirectQuery queries the source on every interaction, and any query returning more than 1,000,000 intermediate rows fails.
• CALCULATE evaluates an expression in a modified filter context, adding new filters and overwriting existing filters on the same column.
• Row-level security in Power BI applies only to users with the workspace Viewer role, not to Admins, Members or Contributors.

Power BI interviews for fresher data analyst and BI roles in India test four areas: Power Query for cleaning, data modelling, DAX, and publishing securely in the Power BI service. Below are 22 questions with model answers you can say aloud, with DAX where it helps, plus a weighting table and a 7-day plan. For other subjects, see the interview questions by subject guide.

Which Power BI topics carry the most weight in interviews?

DAX and data modelling carry the most weight, because they separate people who can build a correct report from people who can only drag visuals.

What Power BI basics are asked first?

Openers check that you have used the tool end to end, not only watched videos.

1. What is Power BI and what are its main components?

Power BI is Microsoft's business intelligence platform for connecting to data, modelling it and building interactive reports. Power BI Desktop is the free Windows application where you build reports, the Power BI service is the cloud platform where you publish, share and schedule refresh, Power BI Mobile shows reports on phones, and the on-premises data gateway lets the service refresh data from sources inside a company network.

2. Walk me through how you build a report.

I connect to the source, such as Excel, CSV or SQL Server, and clean the data in Power Query: fixing types, removing duplicates and splitting columns. Then I build a star schema model with relationships and a date table, write DAX measures for the KPIs, and design visuals around the questions the business asked. Finally I publish to a workspace, set scheduled refresh and apply row-level security if different users should see different data.

3. What is the difference between a report, a dashboard and an app?

A report is a multi-page, interactive set of visuals built on one semantic model. A dashboard is a single page in the service made of tiles pinned from one or more reports, used for a quick overview. An app packages reports and dashboards from a workspace for distribution to a wider audience, so viewers do not need access to the workspace itself.

What Power Query questions should you prepare?

Expect at least one cleaning scenario, because real data is never ready to model.

4. What is Power Query, and what is M?

Power Query is the data preparation engine in Power BI, where you connect to sources and transform data before it loads into the model. Every step you click is recorded as M code, the Power Query formula language, which you can see in the Advanced Editor. Doing transformations here, rather than in DAX, keeps the model smaller and the logic in one place.

5. What is the difference between Merge and Append?

Merge joins two queries side by side on matching key columns, like a SQL join, and supports join kinds such as left outer, inner and full outer. Append stacks queries on top of each other, like a SQL UNION, and is used when you have the same columns split across files, such as monthly sales sheets. A quick way to remember: merge adds columns, append adds rows.

6. How do you clean a messy dataset in Power Query?

I set correct data types first, then remove duplicates and blank rows, trim and clean text, replace or filter nulls, split combined columns, and unpivot wide month columns into rows. I also rename columns to business-friendly names and remove columns the report does not need. When loading a folder of files, I use Combine Files so new monthly files are picked up on refresh.

What data modelling questions are asked?

Modelling questions decide whether the interviewer trusts your numbers.

7. What is a star schema, and why does Power BI prefer it?

Microsoft's star schema guidance describes fact tables, which store events such as sales with keys and numeric columns, and dimension tables, which describe entities such as products, customers and dates. Dimensions filter and group, facts are summarised. In a one-to-many relationship, the "one" side is the dimension and the "many" side is the fact. This shape keeps DAX simple and queries fast, so avoid one giant flat table.

8. What should you know about relationships and cardinality?

Most relationships should be one-to-many from dimension to fact, with single-direction filtering. The star schema guidance notes only one relationship between two tables can be active; others must be inactive and used with USERELATIONSHIP in a measure. For role-playing dates such as order date and ship date, it recommends separate date tables, each with its own active relationship, so users can filter by both. Use bi-directional filtering sparingly, since it can create ambiguity and slow the model.

Sales by Ship Date =
CALCULATE ( [Total Sales], USERELATIONSHIP ( Sales[ShipDate], 'Date'[Date] ) )

9. Why do you need a date table?

Time intelligence functions such as TOTALYTD and SAMEPERIODLASTYEAR need a continuous date table with one row per day and no gaps. A dedicated date table also gives you columns like month name, quarter and financial year, which in India usually runs April to March. Mark it as a date table in Power BI and relate it to every fact table date column.

10. What is the difference between Import, DirectQuery and Live connection?

According to Microsoft Learn on DirectQuery, Import copies data into the in-memory model and gives the fastest, fullest experience, with up to 8 scheduled refreshes a day on Pro and up to 48 on Premium or PPU. DirectQuery leaves data in the source and queries it on every interaction, which suits very large or frequently changing data but limits modelling, and queries returning over 1,000,000 intermediate rows fail. A Live connection reuses an existing published model or Analysis Services model as is. Microsoft recommends starting with Import.

What DAX questions should you expect?

DAX is the core of most Power BI technical rounds; expect to write two or three measures.

11. What is the difference between a calculated column and a measure?

A calculated column is evaluated row by row, as Microsoft's calculated columns page explains, and in Import mode it is stored in the model, so it adds size and refresh time. A measure is evaluated at query time in the filter context of each visual and is not stored per row. Use a column when you need to slice, filter or put a value on an axis, such as an age band; use a measure for aggregations such as total sales or profit margin.

12. What are row context and filter context?

Row context means "the current row", which exists in calculated columns and iterator functions such as SUMX. Filter context is the set of filters coming from slicers, visual rows and columns, and the filter pane, which decides which rows a measure sees. A measure shows a different value in each cell of a matrix because each cell has a different filter context.

13. What does CALCULATE do?

The CALCULATE documentation explains that it evaluates an expression in a modified filter context: a new filter on a column not already filtered is added, and a filter on a column already filtered overwrites it. Used without filters inside row context, it performs context transition, turning the current row into a filter. It is the most important DAX function to understand.

Blue Sales = CALCULATE ( SUM ( Sales[Amount] ), 'Product'[Color] = "Blue" )

14. What is the difference between SUM and SUMX?

SUM adds up a single column. SUMX is an iterator: it goes row by row through a table, evaluates an expression for each row, then adds the results. Use SUMX when the value must be computed per row first, such as quantity times unit price when there is no amount column.

Revenue = SUMX ( Sales, Sales[Quantity] * Sales[Unit Price] )

15. How do you calculate year-over-year growth?

Create a base measure, a prior-year measure using SAMEPERIODLASTYEAR with a proper date table, and divide the difference by the prior year with DIVIDE, which returns blank instead of an error when the denominator is zero.

Total Sales = SUM ( Sales[Amount] )
Sales LY = CALCULATE ( [Total Sales], SAMEPERIODLASTYEAR ( 'Date'[Date] ) )
YoY % = DIVIDE ( [Total Sales] - [Sales LY], [Sales LY] )

16. How do you show each category's percentage of the total?

Divide the measure by the same measure with filters removed from the category column. REMOVEFILTERS (or ALL) clears the category filter in the denominator, while other filters such as year still apply. ALLEXCEPT keeps only the columns you list and removes all other filters on that table.

% of Total = DIVIDE ( [Total Sales], CALCULATE ( [Total Sales], REMOVEFILTERS ( 'Product'[Category] ) ) )

What visual and report design questions come up?

These questions check whether your report helps a manager make a decision.

17. What is the difference between filters and slicers, and what filter levels exist?

Slicers are visuals on the canvas that report users click to filter. The filter pane applies filters at visual level (one visual), page level (all visuals on a page) and report level (every page). Use slicers for filters users change often, such as region or month, and the filter pane for fixed scope, such as excluding test data.

18. What is the difference between drill-down and drill-through?

Drill-down moves through a hierarchy within the same visual, such as year to quarter to month. Drill-through takes the user to a separate detail page filtered to the item they right-clicked, such as one customer's orders. Drill-through pages keep summary pages clean while still allowing detail.

What Power BI service and security questions are asked?

Expect at least one question on RLS and one on refresh.

19. What is row-level security and how do you set it up?

Row-level security restricts which rows a user sees. Per Microsoft's RLS guide, you define roles with DAX filters in Power BI Desktop under Manage roles, publish, then add members to roles in the service and validate with Test as role. Dynamic RLS uses USERPRINCIPALNAME() against a user mapping table. RLS applies only to workspace Viewers, not to Admins, Members or Contributors.

[ManagerEmail] = USERPRINCIPALNAME ()

20. What is a gateway, and when do you need one?

The on-premises data gateway is software installed inside the company network that lets the Power BI service reach on-premises sources such as a local SQL Server or files on a shared drive. You need it for scheduled refresh or DirectQuery against those sources. Cloud sources such as SharePoint Online or Azure SQL usually do not need it.

21. How do workspaces and sharing work?

Workspaces are collaboration areas where creators publish content; members get roles such as Admin, Member, Contributor or Viewer. You can share individual reports, publish an app to a wider audience, or embed reports in Teams or SharePoint. For sensitive data, combine Viewer access with RLS so people see only their rows.

22. How do you make a slow Power BI report faster?

Start with the model: remove unused columns, reduce high-cardinality columns such as timestamps, use a star schema and prefer measures over calculated columns. Then check visuals with Performance Analyzer, reduce the number of visuals per page, and simplify DAX that iterates over large tables. In DirectQuery, check whether the source query itself is slow.

What do most guides on Power BI interview questions get wrong?

Many guides teach one flat table and lots of calculated columns, because that is how Excel users start. Microsoft's own guidance points the other way: a star schema with explicit measures, transformations pushed into Power Query, and Import as the default storage mode. Guides also say RLS "secures the report for everyone"; in fact Microsoft documents that it applies only to the Viewer role, so a colleague with Member access sees all rows. Finally, many still describe a single date table with several active relationships, which Power BI does not allow; only one relationship between two tables can be active.

How should you revise Power BI in 7 days?

Use one public dataset, such as a sales or HR dataset, and build a single report through the week.

1. Day 1: Install Power BI Desktop, load the data, clean it in Power Query, practise merge and append.
2. Day 2: Build a star schema with a date table; set relationship directions.
3. Day 3: Measures vs columns, row vs filter context, CALCULATE, SUM vs SUMX.
4. Day 4: Time intelligence: YTD, prior year, YoY %, and % of total with REMOVEFILTERS.
5. Day 5: Design two report pages with slicers, a drill-through page and tooltips.
6. Day 6: Publish to the service, set refresh, add a static and a dynamic RLS role.
7. Day 7: Answer all 22 questions aloud and present your report in three minutes.

If you are still learning the tool, follow how to learn Power BI for jobs, and build on ideas from Power BI projects for a portfolio. The PL-300 Power BI certification guide covers the exam route, and how to prepare for technical interview questions covers the round itself.

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FAQ

What is the difference between a measure and a calculated column in Power BI?

A calculated column is computed row by row and, in Import mode, stored in the model, so it increases size and refresh time; use it to slice or filter, such as an age band. A measure is computed at query time for each visual's filter context and is not stored per row; use it for totals, ratios and growth figures that respond to slicers.

Is DAX hard for freshers?

The basics are approachable if you know Excel formulas: SUM, AVERAGE, DIVIDE and simple CALCULATE filters can be learnt in a few days. The hard part is understanding row context, filter context and context transition. Practise by writing the same measure several ways and checking the result in a matrix until each number makes sense to you.

Which is better, Import or DirectQuery?

Microsoft recommends starting with Import because it gives the fastest reports and the full modelling feature set. Choose DirectQuery when data is too large to import, changes too often for scheduled refresh, or must stay in the source for governance. DirectQuery reports depend on source speed and have modelling limits, so test performance before committing.

How do you implement dynamic row-level security in Power BI?

Add a mapping table that links each user's sign-in email to the rows they may see, such as region or manager. In Power BI Desktop, create a role with a DAX filter comparing that column to USERPRINCIPALNAME(), publish, add users or security groups to the role in the service, and validate with Test as role. Remember RLS only restricts Viewers.

Should I get the PL-300 certification for a Power BI job?

PL-300 is Microsoft's Power BI Data Analyst certification and can help a fresher's resume pass screening, but interviews still test hands-on skill. A published report with a clean star schema, sensible DAX measures and RLS that you can explain is the stronger signal. If you take the exam, build the portfolio project alongside it.

What Power BI projects should a fresher show in interviews?

One or two end-to-end reports on realistic data work best: a sales performance report with YoY and % of total measures, or an HR attrition report with drill-through to employee detail. Show the Power Query steps, the star schema diagram, a few well-named measures and one RLS role, and be ready to explain every number on the page.

Final thoughts

Power BI interviewers trust candidates who can explain why a number is right, which comes from a clean model and well-understood DAX. Build one report through the 7-day plan, practise the answers aloud, and check your resume against a real BI analyst listing with the Asuraa resume reviewer.