Import vs Direct Query vs Direct Lake in Microsoft Fabric

In the world of data analytics and business intelligence, performance and flexibility are everything. With the introduction of Microsoft Fabric, understanding how your semantic model interacts with your data source becomes even more critical.

When building Power BI reports or semantic models in Microsoft Fabric, you can choose from three core data connectivity modes:

• Import

• Direct Query

• Direct Lake

  
  

Each of these modes has unique advantages and trade-offs. In this blog, we’ll explore the differences, ideal use cases, performance considerations, and recommendations for choosing the right one in your Microsoft Fabric projects.

Import Mode

In Import mode, Power BI (or your Fabric semantic model) imports a snapshot of data from the source into a highly compressed in-memory engine called VertiPaq. All queries run against this in-memory dataset, making it the fastest mode in terms of performance.

✅ Pros:

• Blazing-fast performance due to in-memory caching.

• Full support for DAX and Power BI features.

  
  

❌ Cons:

• Data can become stale; requires scheduled or manual refresh.

• Refresh can be slow for large datasets.

• Limited real-time capabilities.

  
  

Best Use Cases:

• Daily/weekly sales reports.

• Historical trend analysis.

• Scenarios where data freshness is not mission critical.

Direct Query Mode

Direct Query mode lets Power BI connect directly to the data source and run queries in real time—without storing the data in memory. This means your reports always show the latest data, but performance depends on the speed and load of the source system. It's great for real-time dashboards but can be slower than Import mode and has some limitations with complex DAX calculations.

✅ Pros:

• Real-time data access.

• No need to manage data refresh.

  
  

❌ Cons:

• Slower performance due to live queries.

• Limited DAX functionality and performance optimizations.

• Dependency on source system availability and performance.

  
  

Best Use Cases:

• Real-time dashboards (e.g., sales today, inventory levels).

• Scenarios where data changes frequently and needs to be reflected instantly.

Direct Lake Mode

Direct Lake mode in Microsoft Fabric lets Power BI read data directly from files stored in OneLake without copying it. It gives you fast performance like Import mode using the VertiPaq engine, but with real-time data like Direct Query, it gives you best of both. It’s great for big, fresh data and doesn’t need a refresh every time—Power BI just reads what’s already there.

✅ Pros:

• Near real-time data access.

• In-memory performance without scheduled refreshes.

• Leverages open formats (Delta Lake) stored in OneLake.

  
  

❌ Cons:

• Not available for external or non-Fabric sources.

• Cannot create calculated column within report using Dax.

  
  

Best Use Cases:

• Fabric-native data solutions using Lakehouse or Warehouse.

• Reports needing fresh data with high performance and zero refresh.

Comparison Table

Feature	Import	Direct Query	Direct Lake
Performance	⭐⭐⭐⭐⭐	⭐⭐	⭐⭐⭐⭐
Real-time Data	❌	✅	✅
Data Refresh Needed	✅	❌	❌
Storage in Power BI	✅	❌	❌
DAX & Power BI Features	Full Support	Limited	Near Full Support
Data Source	Any	Selective	Fabric Lakehouse /Warehouse
Use Case Fit	Historical	Real-time	Real-time + performant

Conclusion

With Microsoft Fabric bringing everything under one unified platform, Direct Lake mode stands out as a true game-changer—delivering near real-time performance without the hassle of scheduled refreshes or heavy query loads. But that doesn't mean Import and DirectQuery are obsolete. Each mode has its strengths, and choosing the right one depends on your data architecture, performance needs, and business goals. The key is understanding when to use what—and aligning it with your data strategy for the best results.