Q1. What is power BI?
Microsoft’s Power BI is a robust business analytics tool that can transform diverse, disconnected data sources into interactive and valuable insights. These sources may include Excel spreadsheets or hybrid data warehouses hosted on-premises or in the cloud. With Power BI, you can effortlessly connect to all your data sources and share your insights with anyone.
Q2. Why should we use Power BI?
Power BI allows non-technical users to connect, visualize, and analyze data from multiple sources, enabling better business decisions.
Q3. Differentiate power BI & Tableau
|Measures||Uses MDX||Uses DAX|
|Data||Handles large volumes of data||Qualified to handle a limited amount of data|
|Users||Best suitable for experts||Suitable for both experts and beginners|
|Cloud||Capable of supporting the cloud with ease||Finds it difficult due to limited capacity|
Q4. Differentiate Power Query & Power Pivot
|Power Query||Analyzing data||ETL service tool used to extract, transform and load data|
|Power Pivot||Getting and transforming data||In-memory data modeling component used for data analysis|
Q5. Name some data category types used in power BI?
This is one of the important power bi interview questions and here are some data category types used in Power BI –
- Power BI uses various data category types
- “Text” is a data string
- “Boolean” is a true or false type
- “Number” can be used to perform functions like finding averages and fractions
- “Date and Time” are used to extract specific data such as time, year
Q6. Major components of Power BI?
This question often comes as one of the important power bi interview questions and The major components of PowerBI are as follows :
Each component of Power BI can be described as follows:
- Power Query: Extracts and transforms data from databases like Oracle, SQL, and Excel.
- Power Pivot: Used for data modelling with DAX functions to create relationships between tables and generate values for Pivot Tables.
- Power View: Provides interactive views of data with filters and slicers for data analysis.
- Power BI Desktop: An integration tool for Power Query, Power View, and Power Pivot to create advanced queries, models, reports, and dashboards.
- Power BI Mobile Application: An interactive display of dashboards available for Android, iOS, and Windows.
- Power Map: Presents geospatial data visualization in 3D mode with the ability to highlight data based on geographical location.
- Power Q&A: Provides answers to user questions with representations generated by Power View.
Q7. Describe the building blocks of Power BI
The building blocks of Power BI is yet another type of power BI interview questions:
- Visualizations – A visual representation of data like a chart or map.
- Data Sets – A collection of data that Power BI uses to create visualizations.
- Reports – A collection of visualizations that appear together on one or more pages.
- Dashboard – A Power BI dashboard is a collection of visuals displayed on a single page that can be shared with others. Typically, the visuals are carefully chosen to provide a quick overview of the data or story that you want to convey.
- Tiles – It’s a single visualization on a report or a dashboard. It’s a rectangular box that holds an individual visual.
Q8. What are the various power BI versions?
Power BI offers three versions:
- Microsoft Power BI Free/Desktop: For anyone to visualize their business insights from data.
- Microsoft Power BI Pro: The full version with unlimited viewing, reporting, and sharing, which Power BI Desktop lacks.
- Microsoft Power BI Premium: It provides a dedicated capacity unit for all users in the organization instead of a per-user license.
Q9. Name some popular types of filters available in Power BI
Q10. What data sources can Power BI connect to?
Power BI offers a wide range of data sources, which can be categorized into three groups:
- Files – Users can import data from Excel (.xlsx, xlxm), Power BI Desktop files (.pbix), and Comma Separated Value (.csv) files.
- Content Packs – These are groups of related files or documents that can be shared and stored together. Content packs in Power BI can come from service providers like Google Analytics, Marketo, or Salesforce or other users within the organization.
- Connectors – Power BI has connectors to various databases and datasets such as Azure SQL, Database and SQL, Server Analysis Services tabular data, etc.
Q11. How to create and manage relationships in Power BI Desktop?
Power BI utilizes relationships to define connections or relations between tables for multi-table analysis.
To create and manage relationships in Power BI Desktop, follow these steps:
- Click on the Home tab and select Manage Relationships > New.
- In the Create Relationship dialogue box, choose a table from the first table drop-down list, then select the column you want to use in the relationship.
- Choose the other table you want to include in the relationship from the second table drop-down list. Choose the other column you want to use, and then select OK.
Q12. What are different connectivity modes in Power BI?
Power BI offers three distinct modes of connectivity:
- Import Mode:
Import Mode is the default mode in Power BI, and it’s designed for fast performance. It allows you to import data from various sources, and the data is stored in the disk. When querying or refreshing data, the imported data is fully loaded.
- Direct Query Mode:
Direct Query Mode is another way to import data from an existing data source. When the data volume is too large, Direct Query Mode can help to avoid data refresh times that can be time-consuming.
- Composite Mode:
Composite Mode is a combination of Import and Direct Query modes. It supports calculated tables, which Direct Query Mode doesn’t. It delivers the best of both Import and Direct Query modes.
Q13. Where is the data stored in Power BI?
PowerBI stores its data in two main repositories: Azure Blob Storage and Azure SQL Database. User-uploaded data is usually stored in Azure Blob Storage, while Azure SQL Database stores all the system’s metadata and artifacts.
Q14. Can you tell me the difference between Power BI personal gateway & Data Management gateway?
The Power BI Personal Gateway is utilized to enable access to on-premises data sources from reports deployed on Power BI service. On the other hand, the Data Management Gateway is an application that installs the gateway on the source data machines to enable report deployment on SharePoint and schedule automatic data refresh.
Q15. How to perform query tasks on a power BI desktop?
To access Power Query in Power BI Desktop, click the Edit Queries button on the Home tab of the ribbon interface. This will open the Power Query Editor, where you can apply various transformations to your data before loading it into the data model. Keep this as one of the essential power bi interview questions in mind to keep your grades high!
Q16. How do you create a group in Power BI?
To group fields in Power BI, you can select the fields you want to group, then right-click on them and select the “New Group” option from the context menu. This will open the “Group” dialogue box, where you can enter a name for the group and set the group’s properties. Once you click “OK,” the fields will be grouped together, and a new field will be created in the Fields pane with the group name.
Q17. Explain M language in Power BI
M is a functional programming language used to manipulate and transform data in Power Query Editor. It allows users to perform various data preparation tasks such as filtering, sorting, merging, and aggregating data from different sources. In addition, the Power Query M formula language creates custom functions, performs calculations, and transforms data in Power BI.
Q18. Define the Time Intelligence Function
The Time Intelligence function allows users to manipulate data with the help of periods.
Q19. How many active relationships are possible between tables in Power Pivot models & how many inactive ones can they have?
Regarding the active relationships between tables, only one is possible for Power Pivot data models, represented by continuous (not broken) lines.
For inactive relationships, you can have several of them, which are characterized by dotted lines.
Q20. What functions does the Power BI Query editor have?
- Data import to a new group
- Parameter management
- Column, row, and group handling options
- Column renaming and value replacement capabilities
- Ability to run R queries
- Custom column creation using DAX formulas
Q21. Name the critical features of Power BI
- Power BI enables data visualization
- Visualized data can be shared with others in the organization
- It supports an omni-view to display data from various sources
- The output can be displayed across multiple devices
- Power BI offers interactive dashboards and reports.
Q22. What is DAX?
Data Analysis Expression (DAX) is a powerful formula language for performing calculations and data analysis. It comprises functions, constants, and operators that can manipulate data sets and generate insightful reports.
DAX is a functional language with conditional statements, nested functions, and value references. Its formulas can be numeric (integers, decimals, etc.) or non-numeric (string, binary). To write a DAX formula, you always begin with an equal sign, followed by the name of the project, the start of the DAX formula, the DAX function to be used, parentheses to define arguments, the name of the table, the name of the field, and an operator.
Q23. Name 3 crucial DAX rules or concepts
DAX (Data Analysis Expressions) has key concepts such as contexts, functions, and syntaxes.
- Context: A row context is applied to a specific row in a table when a formula’s function affects the row. Filter context is applied when multiple filters are used in a calculation.
- Function: Functions are values or “arguments” used in a specific order to perform a computation. Various categories include statistical, date or time, and logical functions.
- Syntax: Syntax rules are essential when creating a formula in DAX. Not adhering to the syntax can lead to error messages.
Q24. Define the purpose & benefits of using the DAX function
DAX has a wide range of applications beyond Power BI. Learning DAX as a functional language can enhance your skills as a data professional. DAX is built on a complex system of nested filters that significantly enhance the performance of tasks such as data merging, modelling, and filtering tables.
Q25. Steps to follow to carry out dynamic filtering
- Set up the data
- Publish a report to Power BI
- Publish the report to the group workspace
- Make a filter link
- Make a calculated column using a DAX formula to define the values of the column
- Test and publish the overview report
Q26. What is an incremental refresh?
Incremental refresh is a technique that involves dividing data into segments that require frequent refreshes and those that don’t. This enables the separate refresh of only the data segments that require frequent updates, resulting in faster and more efficient refreshes.
Q27. Explain the embed code
The embed code is a code that is generated when you want to share a link with other users. This link is used to publish data on the web and is created by Power BI. The link corresponds to the Power BI report.
Q28. What are filters in Power BI?
Filters are an essential feature in Power BI that applies mathematical and logical conditions to data to narrow down the information displayed in rows and columns. Power BI offers several types of filters, including:
- Manual filters
- Auto filters
- Include/Exclude filters
- Drill-down filters
- Cross Drill filters
- Drillthrough filters
- URL filters (transient)
- Pass-Through filters
Q29. List some limitations of using Power BI
Here are some limitations of using Power BI:
- Power BI does not support file sizes larger than 1 GB and does not allow the mixing of imported data and data accessed through real-time connections.
- Only a limited number of data sources allow real-time connections to Power BI reports and dashboards.
- Sharing dashboards and reports are limited to users with the same email address used for login.
- Dashboards do not support passing user, account, or other entity parameters.
Q30. Explain types of refresh options in Power BI
Here are the four types of refresh options provided in Microsoft Power BI, explained in brief:
- Package refresh – This option syncs your Power BI Desktop or Excel file between the Power BI service, OneDrive, or SharePoint Online. It enables you to update your Power BI reports and dashboards with the latest Power BI Desktop or Excel file changes.
- Model or data refresh – This option refreshes the dataset within the Power BI service with data from the original data source. It helps you keep your Power BI reports and dashboards up-to-date with the latest data changes made in the original data source.
- Tile refresh – This option updates the cache for tile visuals on the dashboard every 15 minutes once data changes. It helps you display the latest data changes in your Power BI reports and dashboards.
- Visual container refresh – This option refreshes the visible container and updates the cached report visuals within a report once the data changes. It helps you keep your Power BI reports and dashboards up-to-date with the latest data changes from the original source.
Q31. How can you refresh data in Power BI?
You can refresh data in Power BI by scheduling a refresh in the Gateway.
Q32. Can you have over 1 functional relationship between 2 tables in the power pivot data model?
No. Multiple inactive relationships can exist between two tables, but only one active relationship can exist at a time between two tables in a Power Pivot data model. Therefore, the inactive relationships are represented by dotted lines, while the active relationship is represented by solid lines.
Q33. Is it possible to have a table in the Power Pivot data model that has no relationships with other tables?
Yes, it is possible to have a disconnected table in the Power Pivot data model for two main reasons:
- The table is a parameter table where users can select values in slicers.
- The table acts as a placeholder for metrics in the user interface.
Q34. Name some commonly used tasks in the Query Editor.
- Connect to data
- Shape and combine data
- Group rows
- Pivot columns
- Create custom columns
- Query formulas
Q35. What are the categories of data types?
- Power BI
- Online Services
Q36. Define grouping
When working with visuals in Power BI Desktop, you can arrange your data into sections using grouping. To create your own groups and bins, you can select multiple elements in the visual by holding down Ctrl and clicking on them. Then, right-click on one of the selected elements and select “Group” from the menu that appears. In the Groups window, you can customize your groups by creating new ones or modifying existing ones.
Q37. In Power BI, where can you reshape data?
You can reshape data in the Data Editing section of Power BI.
Q38. Why must you sign up with a work email for Power BI?
Power BI does not support email addresses provided by telecommunications providers and consumer email services, so a work email is necessary to sign up.
Q39. Which canvas in Power BI uses visualizations to tell a story on a single page?
The Power BI service dashboard is a canvas that uses visualizations to depict a story on a single page.
Q40. What are the basic requirements for using Power BI?
You need a web browser and a work email address to use Power BI. Currently, email addresses ending in “.mil” and “.gov” are not supported.
Q41. Does Power BI support mobile devices?
Yes, Power BI supports mobile devices, including iOS devices, Windows 10 devices, and Android smartphones. In addition, power BI apps can be installed from Google Play, Apple Store, and Windows Store.
Q42. Which work email addresses are currently supported by Power BI?
Power BI supports work email addresses ending in “.org” and “.edu”.
Q43. How do you consolidate inquiries in Power BI?
Inquiries in Power BI are consolidated using Join Queries.
Q44. What is an on-premise gateway?
The on-premise gateway is a bridge that helps you transfer data safely and securely between on-premise (not on the cloud) and Power BI.
Q45. Name two types of connectivity modes in Power BI?
Two connectivity modes used in Power BI are Import and Direct Query.
Q46. What are data destinations for Power Queries?
Power Queries can be loaded to a worksheet table or the Excel Data Model.
Q47. What are the advantages of using a variable in Power BI?
Variables help create more logical queries and can be used for multiple DAX functions.
Q49. Why use a selection pane in Power BI?
Selection Pane helps control visuals that require display and allows combining multiple visual pages into groups, used in bookmarking.
Q50. How to handle Many-to-Many relationships in Power BI?
The crossfiltering option in Power BI can be used to address Many-to-Many relationships.
So, these Power BI interview questions cover a wide range of topics related to Power BI, including data editing, data refresh, Power Query, Power Pivot, Power BI service, visuals, gateways, DAX functions, and many more.
These Power BI interview questions and answers can be used as a helpful resource for preparing for a Power BI interview, whether you are a beginner or an experienced user. It’s important to have a good understanding of the basics of Power BI and be able to explain your approach to data analysis and visualization using this tool.
With these questions and answers, you can feel more confident in your knowledge and readiness for a Power BI interview.