Shortcut vs Mirroring in Microsoft Fabric

Microsoft Fabric provides robust data management capabilities, enabling organizations to streamline data integration and access. Two essential features within Fabric that enhance data accessibility are Shortcuts and Mirroring. While both serve to connect and manage external data sources, their use cases and functionalities differ significantly. This blog explores the key differences, use cases, and best practices for leveraging Shortcuts vs Mirroring in Microsoft Fabric.

What is a Shortcut in Microsoft Fabric?

A Shortcut in Microsoft Fabric allows users to create a lightweight reference to an external data source without physically copying the data into Fabric. It provides seamless access to data stored in Azure Data Lake, Amazon S3, Google Cloud Storage, Dataverse and Microsoft OneLake.

You can create it by going to a Lakehouse and click on "Get Data", and you'll see an option to add a shortcut there.

Key Features of Shortcuts:

Virtual References: No data movement; it only creates a link to the external dataset.
Low Storage Overhead: As no data is copied, storage consumption remains minimal.
Real-Time Access: Always fetches the latest data from the source.
Supported Data Sources: Azure Data Lake, Amazon S3, Google Cloud Storage, Dataverse and Microsoft OneLake.

When to Use Shortcuts:

When real-time data access is needed without data duplication.
To reduce storage costs by avoiding unnecessary data replication.
When working with large datasets where physical movement would be inefficient.

What is Mirroring in Microsoft Fabric?

Mirroring is a technique that creates a synchronized copy of an external database inside Fabric. Unlike Shortcuts, Mirroring ensures that the data is physically present in Fabric and is continuously updated to stay in sync with the source.

You can create this by clicking the "New Item" button on your workspace homepage.

Key Features of Mirroring:

Physical Copy: Data is ingested and stored in Fabric, enabling faster query performance.
Automatic Synchronization: Keeps the mirrored data up to date with source changes.
Optimized for Performance: Reduces latency for analytical queries by avoiding repeated calls to external sources.
Supports Incremental Updates: Only changed data is synchronized instead of full refreshes.
Supported Data sources: Azure SQL Database, Snowflake, Cosmos DB and Databricks Unity Catalog Tables.

When to Use Mirroring:

When high-performance analytics require fast query execution.
When integrating data from external sources that may have latency or availability concerns.
When historical snapshots or data retention beyond the external system’s retention policy is needed.
When working with structured relational databases requiring robust integration with Fabric’s analytics engine.

Shortcut vs Mirroring: A Quick Comparison

Feature	Shortcut	Mirroring
Data Storage	No data movement; references external data	Data is copied and stored in Fabric
Performance	Queries depend on external source speed	Optimized for fast analytical queries
Real-Time Updates	Always retrieves the latest data	Periodically synchronized with external source
Storage Costs	Minimal, as no data is copied	Requires storage in Fabric

Best Practices for Choosing Between Shortcuts and Mirroring

Assess Query Performance Needs: If performance is a priority, Mirroring is the better choice. If accessing up-to-date external data is more critical, Shortcuts work best.
Consider Storage Costs: If minimizing storage usage is essential, Shortcuts help avoid redundant data copies.
Optimize for Real-Time Access: If your workflows rely on always retrieving the latest data, Shortcuts ensure you are not working with stale data.
Use Hybrid Approaches When Needed: In some scenarios, a combination of both approaches—using Shortcuts for raw data access and Mirroring for high-performance analytics—can provide the best outcome.

Conclusion

Microsoft Fabric offers Shortcuts and Mirroring as two distinct yet complementary mechanisms to manage external data access. Understanding their differences and aligning them with your business needs will help you optimize data storage, performance, and analytics efficiency. Whether you prioritize real-time access with Shortcuts or high-performance analytics with Mirroring, selecting the right approach can significantly impact your data strategy within Fabric.