1. How can Power BI be described and what is its role in business reporting?
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Power BI is a complete data analytics and visualization platform that transforms raw data into interactive reports and dashboards. It consolidates data from multiple sources, processes it and presents insights visually. With Power BI Desktop for creating reports, Power BI Service for cloud sharing and Power BI Mobile for remote access, it streamlines business reporting across devices efficiently.
2. What is DAX in Power BI and why is it important?
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DAX or Data Analysis Expressions is a formula language in Power BI used to create measures, calculated columns and custom tables. It enables advanced calculations, aggregations and logical operations on data. By providing precise computations and dynamic analysis, DAX enhances the data model and supports informed, data-driven business decisions.
3. What types of table relationships exist in Power BI?
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Power BI allows one-to-one, one-to-many and many-to-many relationships between tables. One-to-one links individual rows, one-to-many connects a single row to multiple rows and many-to-many handles multiple matches across tables, often using a bridge table. Properly defined relationships ensure accurate data connections and reliable analysis.
4. How do Import mode and DirectQuery mode differ in Power BI?
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Import mode loads data into Power BI for fast performance and offline analysis but requires scheduled refreshes to stay updated. DirectQuery queries the data directly at the source in real time, providing live updates but sometimes with slower performance. Selection depends on dataset size, update frequency and system capabilities.
5. What are KPIs in Power BI and how are they applied?
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Key Performance Indicators (KPIs) are visual tools that compare actual results against predefined targets. They use colors or symbols to highlight trends and performance levels. KPIs help organizations quickly assess whether metrics meet expectations, fall short or exceed goals, enabling faster, effective decision-making.
6. What types of data sources can Power BI connect to?
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Power BI works with a broad range of data sources, including cloud platforms like Azure, Snowflake and BigQuery, classic databases like SQL Server, Oracle and MySQL and file formats like as Excel, CSV, XML and JSON. It also connects with services such as SharePoint and Dynamics 365, allowing for greater flexibility with a variety of corporate datasets.
7. How does Power BI help monitor business performance with KPIs?
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Power BI enables visualization of business performance by comparing actual outcomes to targets using KPI visuals. Colors, symbols and indicators highlight trends, deviations and progress. By presenting metrics clearly, KPIs allow decision-makers to quickly interpret performance and identify areas that require attention.
8. What is the role of Power Query Editor in Power BI and how is it used?
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Power Query Editor prepares and shapes data before it is loaded into the report model. It allows filtering rows, changing data types, removing duplicates and merging columns, all without writing code. This ensures consistent, clean datasets and simplifies the data preparation process for reporting.
9. What are hierarchies in Power BI and why are they beneficial?
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Hierarchies arrange data into multiple levels, allowing users to drill down from summarized to detailed information. Examples include time hierarchies like Year → Quarter → Month or location hierarchies like Country → State → City. Hierarchies enhance navigation, interactivity and exploration of large, complex datasets.
10. What data connectivity options does Power BI offer?
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Power BI provides Import mode, DirectQuery and Live Connection for data access. Import mode loads data for faster querying, DirectQuery maintains live connections for real-time insights and Live Connection links to Analysis Services models for live reporting. These options offer flexibility depending on dataset size, source and reporting needs.