200+ Power BI Developer Interview Questions and Answers

There are four types of joins in Power BI and SQL: inner join, left join, right join, and full outer join.

• Inner join returns only the matching records from both tables.

• Left join returns all records from the left table and the matching records from the right table.

• Right join returns all records from the right table and the matching records from the left table.

• Full outer join returns all records when there is a match in either the left or right table.

Sum calculates the sum of a column, while Sumx calculates the sum of an expression. Summarize creates a new table with summarized data, while Summarized column adds a calculated column to an existing table.

• Sum is used to calculate the sum of a column in a table.

• Sumx is used to calculate the sum of an expression over a table or a group of rows.

• Summarize creates a new table by grouping and summarizing data from an existing table.

• Summarized column adds a calculated column to an ...read more

Page level filters only filter data on a given page, while report level filters affect all data in the report.

• Report level filters are universal filters

• Page level filters only affect data on a specific page

• Report level filters affect all data in the report

• Page level filters only filter data on a given page

Create a Power BI dashboard using measures and data from an Excel dataset to visualize QC and error metrics.

• Measures Creation: Calculate QC%, Internal Error%, and External Error% using DAX formulas based on the provided dataset.

• Dropdowns: Implement slicers for month and process to filter data dynamically on the dashboard.

• Card Visuals: Use card visuals to display key metrics like QC%, Internal Error%, and Internal Accuracy for quick insights.

• Bar Chart: Create a bar chart to vi...read more

The number of refreshes allowed in a Power BI Premium account depends on the capacity size.

• The number of refreshes allowed varies based on the capacity size of the Power BI Premium account.

• For P1 capacity, up to 48 refreshes per day are allowed.

• For P2 capacity, up to 96 refreshes per day are allowed.

• For P3 capacity, up to 384 refreshes per day are allowed.

• Additional refreshes can be purchased if needed.

There are two types of subscriptions in Power BI Report Server.

• The two types of subscriptions are Power BI Report Server Standard and Power BI Report Server Enterprise.

• The Standard subscription allows for a single server deployment, while the Enterprise subscription allows for a distributed deployment.

• The Enterprise subscription also includes additional features such as high availability and disaster recovery.

• Both subscriptions require a license for each user accessing the re...read more

Calculate is used to modify the filter context of a single expression, while Calculate Table is used to modify the filter context of an entire table.

• Calculate is used to modify the filter context of a single expression.

• Calculate Table is used to modify the filter context of an entire table.

• Calculate can be used to create new measures or modify existing ones.

• Calculate Table can be used to create new tables or modify existing ones.

• Calculate can be used with scalar expressions, ...read more

There are three types of filters in Power BI: visual-level filters, page-level filters, and report-level filters.

• Visual-level filters apply to a specific visual or chart in a report.

• Page-level filters apply to all visuals on a specific page in a report.

• Report-level filters apply to all visuals and pages in a report.

• Filters can be applied to columns, measures, or hierarchies.

• Filters can be used to include or exclude specific data based on conditions.

• Examples: Applying a visual...read more

To enhance the performance of the dashboard, optimize data model, minimize visuals, and use calculated columns sparingly.

• Optimize the data model by reducing unnecessary columns and tables

• Minimize the number of visuals on the dashboard to reduce rendering time

• Use calculated columns sparingly as they can impact performance

• Avoid using unnecessary filters and slicers

• Consider using DirectQuery or Live Connection instead of importing all data

• Use query folding to push data transform...read more

Identify transactions with the same merchant, amount, order ID, and credit card within a 10-minute window.

• Join the transactions table on itself to compare records for the same merchant, amount, order ID, and credit card.

• Use a time condition to ensure the timestamps of the transactions are within 10 minutes of each other.

• Group the results by payment ID and count the occurrences of related transactions.

• Example: If two transactions have the same merchant ID, amount, order ID, an...read more

Bookmarks in Power BI are a feature that allows users to save and organize specific views of a report or dashboard.

• Bookmarks help users to easily navigate and switch between different report views.

• They can be used to save filters, slicer selections, visualizations, and other report settings.

• Bookmarks can be created manually or through Power BI's recording feature.

• They can be accessed and managed through the Bookmarks pane in Power BI Desktop or the Bookmarks menu in Power BI ...read more

Common techniques for data shaping include removing columns/rows, grouping rows, pivoting columns, and creating custom columns.

• Removing unnecessary columns and rows can simplify the data and make it easier to analyze.

• Grouping rows can help aggregate data and provide a higher-level view of the information.

• Pivoting columns can transform the data to make it more readable and easier to analyze.

• Creating custom columns can add additional information to the data and help with analys...read more

Gateway is a tool that allows Power BI to connect to on-premises data sources. Dataflow is a self-service data preparation tool in Power BI.

• Gateway enables Power BI to securely access on-premises data sources.

• Dataflow allows users to extract, transform, and load data from various sources into Power BI.

• Gateway and Dataflow work together to enable data refresh and data preparation in Power BI.

• Gateway can be used to connect to databases, files, and other data sources located on-...read more

Row Level Security is a feature in Power BI that allows you to restrict data access at the row level based on user roles and filters.

• Row Level Security (RLS) is used to control data access in Power BI based on user roles and filters.

• It allows you to define rules that determine which rows of data a user can see.

• RLS can be applied to tables or views in the data model.

• It is commonly used to restrict access to sensitive or confidential data.

• For example, you can use RLS to ensure ...read more

Power BI provides various types of security to protect data and control access.

• Row-level security allows restricting data access based on user roles or filters.

• Data encryption ensures that data is securely stored and transmitted.

• Azure Active Directory integration enables centralized user authentication and access control.

• Power BI service provides access and sharing controls to manage permissions.

• Data loss prevention policies help prevent accidental sharing of sensitive inform...read more

Scheduled refresh allows for automatic updates of data in Power BI datasets.

• Scheduled refresh can be set up in the dataset settings under the 'Scheduled refresh' section.

• Some data sources may require a gateway to be set up for scheduled refresh to work.

• Scheduled refresh can be set to occur at specific intervals, such as daily or weekly.

• Scheduled refresh can also be set to occur at specific times, such as during off-peak hours.

• Scheduled refresh can be monitored and managed thr...read more

Various types of reports can be developed in Power BI.

• Power BI allows the development of interactive dashboards.

• Tabular reports can be created to display data in a structured format.

• Matrix reports are useful for summarizing data in a grid-like format.

• Charts and graphs can be used to visualize data trends and patterns.

• KPI reports can be developed to track key performance indicators.

• Paginated reports are suitable for printing or generating PDFs.

• Drill-through reports allow users...read more

Sql server agent is used for scheduling and automating tasks in SQL Server.

• Automates routine tasks like backups, index maintenance, etc.

• Allows scheduling of jobs to run at specific times or intervals.

• Provides alerts and notifications for job failures.

• Can be used to execute PowerShell scripts or SSIS packages.

• Helps improve database performance and reliability.

Gauge charts are used to visually represent a single value within a given range.

• Gauge charts are commonly used in business dashboards to display key performance indicators (KPIs).

• They provide a quick and intuitive way to assess the current status or progress towards a goal.

• Gauge charts can be used to show metrics such as sales targets, customer satisfaction scores, or production efficiency.

• They are effective in highlighting deviations from the desired value or target.

• Gauge ch...read more

Performance of reports can be improved by optimizing queries, reducing data volume, using efficient visuals, and caching data.

• Optimize queries by removing unnecessary columns and filters

• Reduce data volume by aggregating data at the source or using incremental refresh

• Use efficient visuals like matrix instead of tables for large datasets

• Cache data to reduce query times for frequently accessed data

Role based security can be created in SSAS by defining roles and assigning permissions to them.

• Create roles in SSAS and define permissions for each role

• Assign users or groups to each role

• Use Windows authentication or custom authentication to manage access to roles

• Test the security model thoroughly to ensure it is working as expected

Power BI has various types of filters such as visual, page, report, drill-through, and slicer filters.

• Visual filters apply to a single visual or chart.

• Page filters apply to all visuals on a single page.

• Report filters apply to all visuals in a report.

• Drill-through filters allow users to navigate to more detailed data.

• Slicer filters allow users to filter data across multiple visuals.

DAX is a formula language used in Power BI. It has different types of functions including table DAX functions.

• DAX stands for Data Analysis Expressions

• DAX functions can be categorized into different types such as aggregation, time intelligence, filter, etc.

• Table DAX functions are used to manipulate tables in Power BI

• Examples of table DAX functions include FILTER, SUMMARIZE, ADDCOLUMNS, etc.

Power BI is a powerful business intelligence tool that allows users to visualize and analyze data from various sources.

• Power BI is a business intelligence tool developed by Microsoft.

• It allows users to connect to multiple data sources and create interactive visualizations and reports.

• Power BI provides a wide range of data transformation and modeling capabilities.

• It supports various data visualization techniques such as charts, graphs, and maps.

• Power BI also offers advanced an...read more

Power BI has three connection modes: Import, DirectQuery, and Live Connection.

• Import mode imports data into Power BI and creates a dataset.

• DirectQuery mode connects to the data source and queries data in real-time.

• Live Connection mode connects to a published dataset in Power BI Service.

• Import mode is best for small to medium-sized datasets, while DirectQuery and Live Connection are better for large datasets.

• DirectQuery and Live Connection require a live connection to the data...read more

Yes

• Dealing with complex data transformations

• Handling large datasets and optimizing performance

• Creating dynamic and interactive visualizations

• Integrating Power BI with other data sources

• Implementing security and access controls

DAX query for YTD running total with single year selection and warning for multiple selections.

• Use the DATESYTD function to calculate the year-to-date total.

• Implement a measure to check the number of selected years using COUNTROWS and VALUES.

• Display a warning message using a conditional statement if more than one year is selected.

• Example DAX measure: YTD Total = CALCULATE(SUM(Sales[Amount]), DATESYTD(Sales[Date]))

• Example warning measure: YearSelectionWarning = IF(COUNTROWS(VA...read more