Connectivity Modes for SQL Server in Power BI || Power BI Interview Questions || Power BI
Connectivity Modes for SQL Server in Power BI || Power BI Interview Questions || Power BI
Import Mode:
In Import mode, data is loaded into Power BI's internal VertiPaq engine, which is an in-memory columnar database. When you import data, it is stored and processed within Power BI, allowing for fast querying and data exploration. Here are some key points about Import mode:
Data is loaded from the data source into Power BI's internal storage.
Power BI automatically manages the data refresh based on the specified refresh settings.
You can apply transformations, create calculated columns, and build complex data models within Power BI.
Import mode is suitable when data volumes are moderate, and you require fast response times for interactive visualizations and reports.
It supports various data sources, including Excel, CSV, databases, and cloud services.
DirectQuery Mode:
DirectQuery mode enables Power BI to directly query the data source in real-time, without loading the data into Power BI's internal storage. The data stays in the source system, and Power BI sends queries to the source whenever a user interacts with the report. Here are some key points about DirectQuery mode:
Power BI connects directly to the data source to fetch data when needed.
The data source must support DirectQuery. Commonly supported sources include SQL Server, Azure SQL Database, and Analysis Services.
Power BI retrieves the most up-to-date data from the source system, ensuring real-time reporting.
DirectQuery mode is useful when dealing with large data volumes or when data freshness is crucial.
Some Power BI features, such as calculated tables, certain visuals, and transformations, may not be available in DirectQuery mode.
Performance can be impacted due to the need to query the source system for every user interaction.
Choosing between DirectQuery and Import mode depends on your specific requirements. If you need fast performance, the ability to apply complex transformations, and don't require real-time data, Import mode is generally preferred. On the other hand, if real-time data access and large data volumes are critical, DirectQuery mode is more suitable, even though some features may be limited.
It's worth mentioning that Power BI also offers a hybrid mode called "Composite Models," which allows combining DirectQuery and Import mode in a single report, providing flexibility for different data sources and scenarios.
Power BI
DirectQuery
Import mode
Data modeling
In-memory database
Real-time reporting
Data source connectivity
Data refresh
Performance optimization
Data visualization
Power BI features
Data volume management
Composite models
Query optimization
Data transformation
Business intelligence
Data analysis
Data integration
Data connectivity
Data visualization tools
Self-service analytics
Power BI Desktop
Power BI Service
Performance considerations
Data latency
Data extraction
Data transformation
Data modeling techniques
Data loading
Data caching
Real-time analytics
Database connectivity
Data querying
Data governance
Data security