Here’s the top 50 Power BI Interview Questions and Answers on various topics, such as data modeling, DAX, Power Query, and refresh options galore.
Power BI Interview Questions Answers for Fresher Level
1. What is Power BI?
Power BI is a Microsoft business analytics application that let users to visualize data, share insights, and make informed decisions based on data.
It can connect to numerous data sources, convert raw data into interactive reports and dashboards, and offer real-time analytics.
2. Difference between Power BI and Tableau – features
| Feature | Power BI | Tableau |
|---|---|---|
| Developer | Developed by Microsoft | Salesforce |
| Language | DAX, M (Power Query) | VizQL |
| Cost | More affordable than Tableau | More expensive |
| Integration | Strong with Microsoft ecosystem | Platform-independent |
| Ease of Use | User-friendly for beginners | Better for advanced visualizations |
3. Difference between Power Query and Power Pivot:
| Feature | Power Query | Power Pivot |
|---|---|---|
| Purpose | Data extraction, transformation (ETL) | Data modeling and DAX-based calculations |
| Language | M Language | DAX (Data Analysis Expressions) |
| When to be Used | It is mostly used before the loading data to the model. | It is used after the loading data. |
4. What is Power BI Desktop?
Power BI Desktop is a no-cost Windows program that enables users to create reports by linking to data, shaping it, modeling relationships, and creating visuals. It’s a local reporting development application.
5. What is Power Pivot?
Power Pivot is a data modeling component in Power BI that allows users to build complex data models, define calculated columns/measures using DAX, and establish relationships between tables for advanced analytics.
6. What is Power Query?
Power Query is the ETL power behind Power BI, which imports, cleans, and reshapes data from various sources. Power Query has an easy-to-use GUI as well as supporting advanced data shaping by M language scripting prior to loading it into the model.
7. What is DAX?
DAX (Data Analysis Expressions) is a formula language in Power BI used to build measures, calculated columns, and calculated tables. It works on data models and helps perform advanced data analysis and aggregations, similar to Excel but more powerful.
8. What are Filters in Power BI?
The Filters are tools to narrow down data in reports. They enhance report interactivity and allow focused analysis. Types of filters are:
- Visual-level filters
- Page-level filters
- Report-level filters
- Drillthrough filters
- Slicers
9. What are Custom Visuals in Power BI?
Custom visuals are user-defined or third-party visuals not available in the default set. They can be imported from the Power BI Visuals Marketplace or developed using TypeScript and D3.js.
10. What is GetData in Power BI?
GetData is the data import interface in Power BI. It lets you connect to various sources like Excel, SQL Server, APIs, Azure, Web, etc.. It supports both structured and unstructured data.
11. What are the Various Types of Refresh Options in Power BI?
Full Refresh: This means Power BI removes all the old data and brings in the entire dataset again from the source. It’s like starting fresh every time. Useful when your data keeps changing completely or you don’t mind waiting a bit longer.
Incremental Refresh: Instead of loading everything from scratch, Power BI only updates the data that’s new or changed since the last time. This is super helpful when you’re working with large datasets because it saves time and improves performance.
Scheduled Refresh: With this, you can tell Power BI to automatically refresh your data at certain times (like daily, hourly, etc.). You don’t have to do anything—it updates on its own using the Power BI Service.
Manual Refresh: You do it yourself. Just open Power BI Desktop or Power BI Service and click a button to refresh the data whenever you need. It’s simple and good when you don’t need constant updates.
Live/DirectQuery Refresh: This one doesn’t actually “refresh” in the usual way. Instead, Power BI connects to your data source in real time. So whenever you open a report, it shows the latest data directly from the source. No waiting, always up-to-date.
Dataflow Refresh: If you’re using Power BI Dataflows (which are like data preparation tools inside Power BI), this refresh updates the data in those dataflows. Think of it like keeping your reusable data-cleaning steps updated so all reports using them get fresh data.
12. What are the Various Types of Refresh Options in Power BI?
- Manual Refresh – Triggered manually within Power BI Desktop.
- Scheduled Refresh – Set in Power BI Service for periodic updates.
- Automatic Refresh – Near real-time refresh using DirectQuery or Streaming datasets.
- API-Based Refresh – Triggered programmatically via REST API.
13. What is a Dashboard in Power BI?
A dashboard is one-page canvas with key visualizations from several reports. Used for tracking performance KPIs, it provides real-time insights at a glance. Available only in Power BI Service.
14. Can You Have a Table in the Model Without Relationships?
Yes. A table can exist independently, and it’s often used for:
- Disconnected slicers
- Reference tables
- Custom grouping
However, to participate in cross-filtering, relationships are usually required.
15. What is the CALCULATE Function in DAX?
<strong>CALCULATE()</strong> modifies the filter context of a calculation. It’s the most powerful DAX function used to:
- Apply new filters
- Override existing filters
- Create context-sensitive measures
Syntax:
<code>CALCULATE(<expression>, <filter1>, <filter2>, ...)<span style="background-color: initial; font-family: inherit; font-size: inherit; text-align: initial; color: initial;"></span>Example:
<code>TotalSales2023 = CALCULATE(SUM(Sales[Amount]), Sales[Year] = 2023)Power BI Interview Questions for Intermediate Level
25. Where Does Data Get Stored in Power BI?
Power BI uses a hybrid storage model based on the mode and platform. The data is most of the time stored within Microsoft Azure’s cloud infrastructure because it helps in scalability, security, and high availability.
Some key Azure storage services utilized by Power BI are:
- Azure SQL Database: A relational database-as-a-service that can be used as a direct source or as a data warehouse.
- Azure Blob Storage: Unstructured data object storage, commonly applied to big data sets or raw files that are imported into Power BI.
Locally on the desktop, imported data in Power BI Desktop is stored inside the .pbix file itself through an in-memory VertiPaq engine for quick compression and querying.
This local storage is helpful for quick development before deploying to the cloud.
26. What is Row-Level Security (RLS)?
Row-Level Security (RLS) is an important data governance capability in Power BI that limits data visibility by user role.
It imposes fine-grained access control by dynamically filtering rows of data based on the identity of a user.
RLS is applied through DAX filter expressions against tables in Power BI Desktop. Once roles and their corresponding rules are defined, these are published to the Power BI Service, where mappings from users to roles control which subsets of data are visible at runtime.
This ensures that users can only view the data they are allowed to see, ensuring data confidentiality and compliance.
27. Why Use General Formatting in Power BI?
Applying consistent general formatting is essential for data model accuracy and user comprehension. Proper formatting:
- Enables Power BI’s engine to correctly interpret data types (e.g., distinguishing numbers, dates, and text).
- Enhances visual clarity by standardizing presentation styles (like currency symbols, date formats).
- Facilitates more precise calculations and aggregations by preventing type mismatch errors.
- Improves the overall user experience by making reports intuitive and easier to analyze.
28. What Are the Various Views in Power BI Desktop?
Power BI Desktop offers three main views, each designed for various phases of report development:
- Report View: The core canvas for creating interactive reports and dashboards through drag-and-drop visual elements.
- Data View: Enables users to examine and handle raw tabular data after being imported, beneficial for data profiling, cleansing, and defining calculated columns.
- Model View: Visualizes and controls the schema of data model, such as establishing relationships, hierarchies, and specifying table properties, allowing for efficient design of data structure.
29. What Are the Various Versions of Power BI?
There are various customized versions of Power BI to cater to different users and deployment situations:
- Power BI Desktop: A Windows development environment for designing and testing reports on-premises.
- Power BI Service: Cloud-hosted SaaS solution for publishing, sharing, and collaboration, with features such as scheduled refresh and app workspaces.
- Power BI Mobile: Native mobile apps for iOS and Android, supporting on-the-go report consumption and alerts.
- Power BI Embedded: Developer-targeted offering to embed interactive Power BI visuals into custom applications or websites through APIs.
- Power BI Report Server: An on-premises server solution for organizations requiring data residency or offline capabilities, supporting scheduled report delivery and management.
30. Explain the Building Blocks of Power BI
Understanding Power BI’s core components is vital for designing effective BI solutions:
- Visualizations: Graphical elements such as charts, maps, and gauges that represent data insights interactively.
- Datasets: Collections of data imported or connected to Power BI, forming the foundation for analysis.
- Reports: Multiple-page reports made up of multiple visualizations based on datasets, enabling in-depth exploration.
- Dashboards: Single-page, aggregated views compiling multiple tiles from multiple reports, enabling at-a-glance monitoring.
- Tiles: Standalone units of visualization pinned to dashboards, displaying a snapshot or metric for rapid reference.
Top Power BI Interview Questions for Advanced Level
Q1. What is SSRS and how does it differ from Power BI?
SSRS stands for “SQL Server Reporting Services” and is a server-based report generation tool focused on traditional, code-driven report development, while Power BI is a modern, graphical, cloud-based data visualization platform
SSRS is a Microsoft tool for creating detailed, server-hosted reports mainly used in enterprise environments. Unlike Power BI, it lacks drag-and-drop features and leans more on manual coding for building reports.
SSRS supports only on-premise data, whereas Power BI connects to both cloud and local sources, offering interactive dashboards with AI support like Cortana.
Difference between SSRS and Power BI with features
| Feature | SSRS | Power BI |
|---|---|---|
| Hosting | Server-based Hosting | Cloud-based Hosting is there |
| Interface | It has the Code-centric interface | Visual & interactive interface |
| Licensing | It is mandatory hence,SQL Server license required | It is mostly Free but paid premium are also available with more features. |
| Data Source | On-premises only | On-premises + Cloud |
| AI/NLP Support | No | Yes (Cortana Q&A) |
Q2. What are Paginated Reports?
Paginated reports are the kind you’d print out, they’re neatly arranged and stay the same on every page, so everything looks clean and organized.
Paginated reports are structured, pixel-perfect documents that support multi-page printing. Commonly used for PDFs and Word outputs, these reports are ideal for detailed tabular or financial reports.
They use the.RDL files and maintain across different pages.
Q3. What are Measures in Power BI and how are they created?
Measures in Power BI are like on-the-fly calculations as it is used to quickly get things like totals, averages, or counts based on your data.
The Measures are dynamic formulas used to compute aggregated data (e.g., totals or averages) that change based on report filters. Created in Power BI Desktop, you can add a measure by right-clicking a table or using the Modeling tab.
Once created using DAX, they adjust instantly with user interactions.
Q4. What do you understand by Power BI Gateway?
Power BI Gateway is like a safe connection that lets Power BI (which runs online) reach and use data stored on your company’s local computers or servers, without moving that data to the cloud.
Power BI Gateway enables cloud services to securely access local (on-premises) data. Instead of copying data, it establishes a direct connection, ensuring data never leaves the source unless explicitly requested.
It’s essential for hybrid cloud setups, enabling real-time reporting without compromising security.
Q5. What is Bidirectional Cross-Filtering in Power BI?
It lets filters work both ways between related tables, so you get better control and more accurate results when working with complex data models.
Bidirectional cross-filtering means filter conditions can flow both ways between related tables.
This is particularly useful in many-to-many relationships, allowing a flexible and synchronized filtering experience across multiple tables in a report, improving accuracy in complex data scenarios.
Q6. What do you mean by Power BI Designer?
It’s a separate tool that lets you clean, shape, model, and visualize data, all in one place, to build Power BI reports without needing an internet connection.
Power BI Designer is a desktop application that consolidates Power Query, Power Pivot, and Power View all within a single tool. It allows you to perform work with your data offline: scrub it, create models, andbuild visual reports.
Then, when you’re ready, publish what you’ve created to the Power BI Service so you can access and share it online.
Q7. What is DAX in Power BI?
DAX stands for (Data Analysis Expressions) and is a formula language used to build custom metrics and perform advanced calculations in Power BI.
DAX is a calculation and custom logic language used in Power BI, Power Pivot, and SSAS. It accommodates row-level and context-aware calculations, allowing for advanced analytics such as YoY growth, moving averages, and cumulative totals.
DAX improves interactivity by adapting outputs to filter changes and data table relationships.
Finalize
These were the top interview questions and answers of Power BI that are repetitively asked in interview. If you’ll go through all, then this will surely help you to crack the interview.
To prepare for Power BI interviews, you need to understand the basics like DAX, data modeling, and dashboards. These questions and answers help you revise quickly and feel more confident for the interview.
For more interview question answers here.