Common Power BI Interview Questions (2023) - IQCode's Guide

What is Power BI?

Power BI is a Microsoft tool that offers a range of data visualization features. It simplifies the process of collating data from various sources into a single tool and offers three major components: Power BI services, Power BI Desktop, and Power BI mobile app. These components enable users to create data-driven insights for their businesses, create reports, monitor progress, integrate APIs, and much more.

Why Use Power BI?

Power BI simplifies the process of getting data from different sources and managing it effectively in one tool. Interactive reports can be shared with different industries, such as retail, for free. With numerous opportunities available in the data-driven tech industry, learning Power BI is worth it. Roles such as Power BI data analyst, developer, software engineer, project manager, SQL Server Power BI developer, and consultant are in high demand and offer good compensation to those who have a deep understanding of the tool and can uncover insights to make important business decisions. Power BI has also been recognized as the leader in Gartner’s BI and Analytics report.

Power BI Interview Questions for Fresher's

1. How would you define Power BI as an effective solution?

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Power BI is a comprehensive tool that enables users to integrate and analyze various data sources, generate interactive reports, and gain deep insights into business operations. Its intuitive interface offers a range of features and functionalities, which can be used to solve various business problems. Power BI offers three components, including Power BI Desktop, Power BI mobile app, and Power BI services that cater to the needs of different business roles. Its simplified workflow and ease of use make it an effective solution for businesses of all sizes to gain meaningful insights from their data.

Major Components of Power BI

Power BI has several significant components that are essential to its functioning. These include:

- Power BI Desktop: The primary authoring and report creation tool for Power BI. - Power BI Service: The cloud-based service that hosts and shares Power BI reports and dashboards. - Power BI Mobile App: The mobile version of the Power BI Service that allows users to access and interact with their reports and dashboards on the go. - Power BI Report Server: The on-premises solution for hosting and sharing Power BI reports within an organization's network.

Understanding these components is crucial for effectively utilizing Power BI to its fullest potential.

Various Refresh Options Available

What are the different options for refreshing?

Different Connectivity Modes in Power BI

In Power BI, there are primarily three connectivity modes:

1. Import: This mode imports the data from the data source into Power BI's internal memory, and the data is stored in a compressed format. The imported data can then be used to create reports and dashboards. Import mode is suitable for smaller data sets, as the available memory limits the size of the data sets that can be imported.
2. DirectQuery: In this mode, the data is not imported but instead stays in the data source. Power BI sends queries to the data source, and the results are displayed in the report. DirectQuery is suitable for larger data sets as there are no memory constraints.
3. LIVE Connection: In this mode, data from the source is queried in real-time as the user interacts with the report. This mode is ideal for scenarios where data is constantly changing and requires up-to-the-minute information, such as stock prices or social media feeds.

It's essential to choose the correct connectivity mode when creating reports in Power BI, as it affects the report's performance, data refresh rates, and scalability.

What is Power BI Desktop?

Power BI Desktop is a business analytics and data visualization tool developed by Microsoft. It allows users to connect, analyze, and visualize data from various sources, including Excel spreadsheets, cloud-based and on-premises data sources, and big data sources. Power BI Desktop offers a user-friendly interface with drag-and-drop capabilities, custom visualizations, and a wide range of data modeling and transformation options. It is widely used by business analysts, data scientists, and decision-makers to gain insights and make data-driven decisions.

Where does Power BI store data?

In Power BI, data can be stored in different places depending on where it is being sourced from.

- If the data is being imported into Power BI, it will be stored in the Power BI Desktop file and can then be uploaded to the Power BI service.

- If the data is being connected to live, it will be stored in the original source system and accessed in real-time by Power BI.

- If the data is being stored in a cloud-based service such as Azure, it will be stored in that service and accessed by Power BI.

Overall, where the data is stored will depend on the specific data source and how it is being connected to Power BI.

Available Views:

This depends on the specific context. Can you please provide more information on which system or application you are referring to?

Available Formats

What formats are available?

Power BI's Compatible Data Sources

Power BI is capable of connecting to a variety of data sources, including:

- Excel workbooks<br>
- CSV and text files<br>
- Databases such as SQL Server, MySQL, Oracle, and PostgreSQL<br>
- Cloud-based services such as Azure, SharePoint, and Salesforce<br>
- Big data sources including Hadoop and Spark<br>
- Business applications such as Dynamics 365, Google Analytics, and Adobe Analytics

Understanding Dashboards in Power BI

A dashboard is a visual display of data insights and analysis that provides a quick overview of a business's key performance indicators (KPIs). It is a single page that consolidates multiple charts, reports, and visualizations, allowing businesses to monitor their critical metrics in real-time and in a format that is easy to understand. In Power BI, a dashboard can be customized according to the specific needs of the audience and can be shared securely across the organization or publicly with selected stakeholders.

Power BI Building Blocks

Power BI has several building blocks that are essential for creating and analyzing data visualizations. Some of these building blocks include visuals, datasets, dashboards, reports, and queries. By utilizing these components, users can create powerful and interactive data models that provide valuable insights into their data.

Understanding Content Packs in Power BI

Content Packs in Power BI are pre-built collections or bundles of dashboards, reports, and datasets. These packs allow users to quickly access a set of information that’s relevant to their business or industry. With the help of content packs, users can avoid the hassle of finding, collecting, and formatting the data they need for their analysis. The content packs are created by Microsoft or other third-party providers, who build them based on the requirements of specific industries or applications.

In Power BI, you can access the available content packs from the Power BI service or the Power BI mobile app, where you can view, explore, and interact with them. You can also customize the content packs by manipulating the data, adding custom visuals, or publishing them to different groups or individuals. In order to use content packs, you need to have a Power BI account, and the packs need to be shared with your account or organization.

Power BI Versions

There are several different versions of Power BI available, including Power BI Desktop, Power BI Pro, Power BI Premium, and Power BI Mobile. Each version is designed for specific needs and offers distinct features and benefits. Power BI Desktop is a free, standalone application that allows users to create data models, reports, and visualizations. Power BI Pro is a cloud-based service that offers more advanced features and collaboration tools. Power BI Premium is a paid version of Power BI that provides higher performance and scalability for larger organizations. Power BI Mobile is a mobile application that allows users to view and interact with their Power BI content on their mobile devices.

Purpose and Benefits of using DAX Functions

DAX (Data Analysis Expressions) functions are used in Excel Power Pivot and other Business Intelligence tools to create complex formulas for data analysis. The purpose of using DAX functions is to manipulate and analyze data in a more efficient and effective manner.

There are several benefits to using DAX functions, including:

• Performing calculations on large datasets
• Enhancing data models with calculated columns and measures
• Creating custom calculations specific to business requirements
• Combining multiple sources of data into a single data model for analysis
• Facilitating real-time data analysis

Overall, the use of DAX functions provides a powerful tool for data analysis that can greatly enhance decision-making capabilities in various industries.

What is Power Pivot?

Power Pivot is a Microsoft Excel add-in used for data analysis and business intelligence. It allows users to create sophisticated data models and perform complex analyses using large data sets. With Power Pivot, users can easily connect multiple data sources, create relationships between them, and create calculated columns and measures using Data Analysis Expressions (DAX). Overall, Power Pivot simplifies the process of working with large data sets and enables users to gain insights that are not easily visible with traditional Excel tools.

What is Power Query?

Power Query is a data connection and transformation tool that enables users to import and manipulate data from various sources in a smooth and efficient manner. It is a Microsoft Excel add-in, but it also comes as a feature in other Microsoft products such as Power BI and SharePoint. Power Query simplifies data preparation and aggregation by offering a user-friendly visual interface that allows users to create reusable queries with an intuitive and robust formula language called M.

Differences Between Power BI and Tableau

Power BI and Tableau are both powerful data visualization tools used for business intelligence purposes. However, there are some key differences between the two:

• Power BI is a Microsoft product, while Tableau is a product of Tableau Software
• Power BI is more affordable than Tableau, especially for small businesses
• Tableau has more advanced features and offers more flexibility in terms of customization
• Power BI is more integrated with other Microsoft products, such as Excel and Azure
• Tableau has a larger and more active user community, offering more support and resources

Ultimately, the choice between Power BI and Tableau depends on the specific needs of the business and the level of expertise of its users.

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What is GetData in Power BI?

GetData is a function in Power BI that allows users to extract data from a variety of sources, such as databases or cloud-based platforms. It can be used to load and transform data into a format that is suitable for visualization and analysis within the Power BI tool.

Example:

let Source = GetData("https://exampledata.com", [ApiVersion = "1.0"]), #"Converted to Table" = Table.FromList(Source, Splitter.SplitByNothing(), null, null, ExtraValues.Error), #"Expanded Column1" = Table.ExpandRecordColumn(#"Converted to Table", "Column1", {"Field1", "Field2", "Field3"}, {"Field1", "Field2", "Field3"}) in #"Expanded Column1"

Overview of Filters in Power BI

Filters in Power BI are used to restrict the data displayed in visuals, tables, and charts. They help in analyzing data efficiently by focusing on a specific subset of data. There are different types of filters available in Power BI such as visual-level, page-level, and report-level filters that can be used to refine the data displayed in a report. These filters can be applied to one or more visuals and can be further customized to provide a more refined view of the data. Additionally, Power BI also allows users to create custom filters using advanced functions and expressions, providing greater flexibility in data analysis.

Power BI Interview Questions for Experienced

One important question that may come up in a Power BI interview for experienced professionals is:

What are the types of visualizations in Power BI?

In Power BI, there are several types of visualizations that can be used to represent data in various ways, including:

- Bar chart
- Column chart
- Line chart
- Pie chart
- Donut chart
- Waterfall chart
- Funnel chart
- Gauge chart
- Scatter chart
- Bubble chart
- Map
- Tree map
- Heat map
- KPI visual

Each visualization has its own strengths and weaknesses, and the choice of visualization depends on the data being presented and the intended audience.

Understanding Power BI Services

Power BI Services is a cloud-based business intelligence (BI) platform developed by Microsoft. It allows users to connect, analyze, and visualize their data in a single and interactive dashboard. Power BI Services offers a wide range of features including interactive data visualization, advanced analytics, and data sharing capabilities. It can be integrated with various data sources such as Excel, SQL Server, SharePoint, and many more. With Power BI Services, users can easily create and share reports and dashboards with their team, customers, or stakeholders in a secure and controlled environment.

Overview of the Comprehensive Power BI Workflow

Power BI is a business analytics service provided by Microsoft that enables users to derive insights from their data through interactive visualizations and intuitive dashboards. The comprehensive Power BI workflow consists of the following steps:

1. Data Acquisition: The first step is to acquire data from various sources such as Excel spreadsheets, databases, cloud-based storage, or web services. Power BI supports various data connectors, making it easy to connect to most data sources.
2. Data Transformation: Once the data is acquired, it needs to be transformed so that it can be shaped and cleansed for analysis. Power BI provides a data modeling tool called Power Query, which allows users to transform and clean data using a simple drag-and-drop interface.
3. Data Visualization: After transforming the data, the next step is to create interactive visualizations that help to derive insights from the data. Power BI offers a range of visualization options that make it easy to create charts, graphs, tables, and maps with just a few clicks.
4. Data Analysis: With the data transformed and the visualizations in place, users can now explore the data and extract insights. Power BI provides a range of tools for data analysis, including filters, slicers, and drill-down capabilities.
5. Sharing and Collaboration: Finally, users can share their insights with others by publishing their reports and dashboards to the Power BI Service. Additionally, Power BI offers built-in collaboration features such as commenting and sharing, which allow team members to collaborate on the same report or dashboard in real-time.

By following this comprehensive Power BI workflow, users can extract insights from their data quickly and efficiently, allowing them to make data-driven decisions that can help to drive business growth.

Explanation of Custom Visuals in Power BI

Custom visuals in Power BI refer to the charts, graphs, and other visual representations that are not included in the default library of visualizations. These visualizations are created by third-party developers or users themselves using the Power BI developer tools.

Custom visuals provide users with a wide range of options to display their data in a more engaging and informative way. They can be imported into Power BI from the marketplace or by downloading them directly from the developer's website and then added to reports and dashboards. Popular custom visuals include the Sankey diagrams, word clouds, gauges, and heat maps.

In summary, custom visuals in Power BI enable users to analyze their data in unique and creative ways beyond the default visualizations, providing a more comprehensive and interactive user experience.

Types of Users Who Can Use Power BI

Power BI can be used by different types of users at various levels of an organization, including:

• Consumers: They consume the reports and dashboards created by others. They typically do not create content in Power BI but only view and analyze the data.
• Creators: They are responsible for creating the reports and dashboards in Power BI. They use visualizations, charts, and graphs to present data to the end-users.
• Analysts: They use Power BI to explore the data, find trends, and create custom reports using ad-hoc analysis.
• Data Scientists: They use advanced analytics capabilities of Power BI to create predictive models and perform detailed statistical analysis on data.
• Administrators: They are responsible for managing the Power BI service, creating security policies, and managing user access to data and reports.

By understanding the various types of users who can use Power BI, organizations can effectively leverage this powerful tool to create, analyze, and make decisions based on data.