1. How can Power BI be described and how does it support business reporting?
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Power BI is a data analytics and visualization platform that converts raw data into interactive dashboards and reports. It enables users to pull data from multiple sources, refine it, and build meaningful visual insights. With Power BI Desktop for report creation, Power BI Service for sharing, and Power BI Mobile for viewing, it streamlines modern business reporting across devices.
2. What is DAX in Power BI and why is it significant?
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DAX (Data Analysis Expressions) is a formula language used to build calculations and analytical expressions in Power BI. It allows creation of measures, calculated columns, and custom tables using functions for aggregation, filtering, and logical operations, enabling deep, dynamic, and customized data analysis.
3. What types of table relationships can be built in Power BI?
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Power BI supports one-to-one, one-to-many, and many-to-many relationships. One-to-many links one row to multiple rows, one-to-one links individual rows between tables, and many-to-many relationships allow multiple matches across tables, often requiring a bridge table for accuracy.
4. How do Import mode and DirectQuery mode differ in Power BI?
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Import mode stores data inside Power BI for fast performance and offline use but requires refresh schedules. DirectQuery keeps data in the source system and fetches results live, providing real-time updates but possibly affecting performance. Choice depends on data size, update frequency, and system capacity.
5. What are KPIs in Power BI and how do they function?
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KPIs (Key Performance Indicators) display business metrics against targets, showing current value, goal, and a visual indicator of progress or deviation. They help organizations quickly track performance and identify if objectives are met.
6. What categories of data sources can Power BI connect to?
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Power BI connects to cloud platforms like Azure, Snowflake, BigQuery, traditional databases such as SQL Server, Oracle, MySQL, files like Excel, CSV, XML, JSON, and services including SharePoint and Dynamics 365, providing flexibility across diverse data environments.
7. How does Power BI assist in monitoring performance using KPIs?
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Power BI visualizes actual results against targets using KPI visuals with symbols or color coding, making trends easy to interpret. This instant feedback enhances monitoring and helps in decision-making.
8. What is the purpose of Power Query Editor in Power BI?
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Power Query Editor allows connecting, cleaning, and shaping data before loading it into the report model. Users can adjust data types, remove duplicates, filter records, and combine columns. Its code-free interface streamlines data preparation for structured, reliable datasets.
9. What are hierarchies in Power BI and why are they useful?
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Hierarchies organize data into layered levels for drill-down analysis. Examples include Year → Quarter → Month → Day or Country → State → City. They improve navigation, interactivity, and simplify exploration of complex datasets.
10. What data connectivity options does Power BI provide?
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Power BI offers Import mode, DirectQuery, and Live Connection. Import mode loads data into Power BI for fast queries, DirectQuery fetches data live from the source, and Live Connection connects to SQL Server Analysis Services models for real-time analysis without importing data.