1. What is Power BI and how does it aid business analytics?
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Power BI is a comprehensive business intelligence platform that transforms raw data into interactive visuals and insights. It combines information from multiple sources, organizes it, and presents it through dynamic dashboards and reports. Using Power BI Desktop for report development, Power BI Service for cloud collaboration, and Power BI Mobile for access on the move, it ensures consistent and efficient reporting across devices.
2. Explain DAX in Power BI and its importance.
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DAX, or Data Analysis Expressions, is a formula language in Power BI for creating custom measures, calculated columns, and derived tables. It supports advanced calculations, filtering, and logical operations. DAX enhances the dataset’s analytical capabilities, allowing businesses to perform detailed analysis and make informed decisions.
3. What types of relationships can be established between Power BI tables?
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Power BI allows one-to-one, one-to-many, and many-to-many relationships between tables. One-to-one links a single record in each table, one-to-many connects one record to multiple related entries, and many-to-many enables multiple records in both tables, often through an intermediary table. Proper relationship setup ensures accurate and reliable analysis.
4. How does Import mode differ from DirectQuery mode in Power BI?
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In Import mode, data is stored inside Power BI, providing fast performance and offline accessibility, but periodic refreshes are required. DirectQuery mode connects directly to the data source, retrieving information in real-time, which ensures updated data but may impact speed. The choice depends on dataset size, refresh needs, and infrastructure.
5. What are KPIs in Power BI and how are they applied?
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Key Performance Indicators (KPIs) are visual metrics used to measure actual performance against targets. They use indicators such as colors, arrows, or symbols to highlight trends and results. KPIs help businesses quickly evaluate performance, monitor goals, and take corrective action when needed.
6. Which data sources can be linked to Power BI?
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Power BI supports a wide range of data sources, including cloud platforms like Azure, Snowflake, and Google BigQuery, traditional databases such as SQL Server, Oracle, and MySQL, as well as files like Excel, CSV, XML, and JSON. It also integrates with applications like SharePoint and Dynamics 365, enabling comprehensive enterprise reporting.
7. How does Power BI use KPIs to monitor organizational performance?
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Power BI leverages KPI visuals to compare actual results with defined goals, highlighting progress and gaps. Visual cues like colors and symbols make trends, patterns, and exceptions easily identifiable. This allows stakeholders to quickly grasp performance levels and focus on areas that require improvement.
8. What is Power Query Editor and why is it important in Power BI?
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Power Query Editor is a tool for transforming and preparing data before it enters the Power BI model. It allows users to filter rows, modify data types, remove duplicates, and combine datasets without coding. This ensures clean, structured data ready for accurate reporting and analysis.
9. What are hierarchies in Power BI and why are they beneficial?
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Hierarchies arrange data into multiple levels, enabling drill-down from high-level summaries to detailed views. Examples include time hierarchies like Year → Quarter → Month and location hierarchies like Country → State → City. They improve data navigation, making analysis more interactive and intuitive for users.
10. What types of data connection methods are available in Power BI?
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Power BI provides Import mode, DirectQuery, and Live Connection for data access. Import mode stores data within Power BI for fast performance, DirectQuery maintains a live connection to the source for real-time updates, and Live Connection links to Analysis Services models directly. These options offer flexibility depending on dataset size, source type, and reporting needs.