
Power BI Interview Questions
1. What is Power BI?
Power BI is a business analytics tool by Microsoft that enables users to visualize data, share insights, and make data-driven decisions. It includes features for data preparation, data modeling, and sharing interactive reports.
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Power Query is a data connection tool that allows you to import, transform, and clean data from various sources. It uses the M language for data transformation.
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DAX (Data Analysis Expressions) is a formula language used for creating calculated columns, measures, and custom tables in Power BI. It enables advanced data analysis and aggregation.
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Power BI is designed for business intelligence, providing better capabilities for interactive data visualization, sharing, and reporting, while Excel is a general-purpose tool focused on data analysis and calculation.
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Power BI Gateway is a bridge that facilitates the transfer of data between on-premises data sources and Power BI in the cloud. It can operate in two modes: Personal and Enterprise.
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A dashboard is a collection of visuals (charts, graphs, tables) that provide a snapshot of key performance indicators (KPIs) and important data metrics.
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The Power BI Service is a cloud-based platform that allows you to publish, share, and collaborate on Power BI reports and dashboards with others.
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Tiles are individual visual elements within a dashboard that represent a single piece of data, such as a chart or KPI.
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A report is a collection of visualizations (charts, tables, etc.) based on a single dataset. It can span multiple pages and offer detailed analysis.
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Row-Level Security is used to restrict data access for certain users by filtering the data at the row level based on user roles.
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To improve performance, you can:
A measure is a dynamic calculation in Power BI that aggregates data based on the context of the report, such as a sum or average.
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Visualizations are graphical representations of data, including charts, tables, maps, and gauges, which help in understanding the data insights easily.
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Power BI templates allow you to save and share report layouts, including visualizations, queries, and connections, making it easier to replicate reports with different datasets.
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Custom visuals are user-defined, third-party visuals that can be imported into Power BI to provide additional visualizations not available in the default set.
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Calculated tables are tables that are created by DAX expressions, which are evaluated at the time the model is processed. They are used for more advanced data modeling.
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Bookmarks capture the current state of a report page (filters, slicers, and visuals) and allow you to save and navigate between different views or layouts of a report.
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Q&A allows users to ask natural language questions (e.g., “Total sales by region”) and automatically generate visuals based on the response.
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Power BI requires a date table for time-based calculations and analytics. You can use the built-in date table or create a custom one using DAX.
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A Power BI workspace is a container for datasets, reports, and dashboards where users can collaborate and share resources in the Power BI Service.
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The Power BI API allows developers to interact programmatically with Power BI, enabling them to automate tasks such as embedding reports, managing datasets, or accessing user data.
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A dataset is a collection of data that is used to build reports and dashboards. It can be created from different data sources like databases, Excel files, or web services.
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Power BI integrates with Excel to allow users to publish workbooks, use Excel formulas in Power BI, and import Excel data directly into Power BI for visualization.
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A Key Performance Indicator (KPI) in Power BI is a visual that measures progress toward a business goal using a target value and an actual value.
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In the Power BI Service, you can schedule automatic data refreshes for datasets by defining the refresh frequency and time.
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Power BI allows data integration through the Power Query Editor, where you can merge or append tables from different sources.
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Paginated reports are highly formatted, printable reports that can span multiple pages, ideal for printing invoices, statements, or reports requiring exact formatting.
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In Import Mode, data is loaded into Power BI and stored in memory, allowing for faster query performance. In DirectQuery Mode, data is queried live from the source without storing it in Power BI.
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You can handle missing data using Power Query to fill missing values, remove incomplete rows, or replace nulls with default values during data transformation.
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Power BI Gateways are used to connect on-premises data sources (e.g., SQL Server, Excel files) to the Power BI Service for real-time or scheduled data refresh.
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Power BI Embedded is a service that allows you to embed interactive Power BI reports and dashboards into your applications or websites for a seamless user experience.
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