What’s new with Mirroring in Fabric at Microsoft Build 2025
At Microsoft Build 2025, we are thrilled to show you the latest innovations that we have delivered with Mirroring in Fabric. Mirroring is a powerful feature that allows you to seamlessly reflect your existing data estate continuously from any database or data warehouse into OneLake in Fabric. Once Mirroring starts the replication process, the mirrored data is automatically kept up to date in near real-time. With your data estates landed into OneLake, the data is now available everywhere in Fabric, ready to accelerate your data potential.
Since Fabric Community Conference in March 2025, the Mirroring team has been diligently listening to your valuable feedback and ideas. We have been hard at work to ensure that Mirroring in Fabric can be seamlessly integrated into your production workload. At Build 2025, we are excited to share with you our latest innovations such as introducing Mirroring for SQL server; delivering highly anticipated features for Mirroring for Azure SQL Managed Instance and Cosmos DB; increasing flexibility to customize retention policy of your mirrored data; and expending our Mirroring region support. On top of all these new capabilities, we are proud to announce the general availability of Open Mirroring for you to build your own Mirroring solutions.
Let’s dive-in and explore further the new and exciting announcements of Mirroring in Fabric.
Introducing Mirroring for SQL Server
We are thrilled to announce that Mirroring for SQL Server in Fabric is now in preview. Mirroring for SQL server will support both in market SQL Server versions 2016-2022 and the newly available SQL Server 2025. Once you have your on-premises data gateway configured, you can now mirror from your SQL Server, no matter if your SQL Server is running on-premises or in a virtual machine in the cloud, into OneLake in Microsoft Fabric with database mirroring.
While the overall experience for Mirroring for SQL Server remains the same, our Mirroring engine supports replicating change data from SQL server (2016-2022) with the existing change data capture (CDC) technology.
On the other hand, the brand new SQL Server 2025 is tailor made for Mirroring in Microsoft Fabric and our Mirroring engine supports the latest change feed technology for replicating changes to ensure that there is minimal impact to your operational workload on your SQL Server.
For more details, please refer to: Mirroring for SQL Server in Microsoft Fabric (Preview).
New enterprise-ready features with Mirroring for Azure SQL Managed Instance
As we are continuing to focusing on improving on enterprise readiness for Mirroring in Fabric, we are thrilled to announce the latest features that will help you replicate your Azure SQL Managed Instance data into Fabric OneLake running in productions.
- Mirroring supports Azure SQL Managed Instance behind a firewall is now in preview: With this highly demanded feature now publicly available, you can now use data gateway to connect to your Azure SQL Managed Instance database for mirroring, removing the necessity of opening public access. The data gateway ensures secure connections to the source databases via private endpoint.
- Mirror tables without Primary Keys: We have removed the limitation and now you can mirror tables from your Azure SQL MI database even if they don’t have a primary key, such as heap tables, offering increased flexibility.
- Support for expanded Data Definition Language (DDL): In addition to Alter/Drop/Rename tables/column, you can now Truncate tables in your source Azure SQL MI databases while mirroring is actively replicating your data.
Learn more from New features in Mirroring for Azure SQL Managed Instance – private endpoint support and more.
Mirroring for Azure Cosmos Database is now Refreshed with amazing New Features
As we are approaching Microsoft Build, we are thrilled to announce the latest refresh of Mirroring for Azure Cosmos DB preview! This refresh for Mirroring for Azure Cosmos DB introduces key enhancements like Microsoft Entra ID authentication, container selection, support for special characters in column names, and even vector search compatibility for AI workloads. With features like auto schema inference, this release makes it easier than ever to replicate Azure Cosmos DB data into Fabric OneLake.
To learn more, refer to the Fabric Mirroring for Azure Cosmos DB: Refresh Now Live with New Features (Preview).
Customize retention period for mirrored data
The Mirroring engine continuously replicates your existing data estate from various databases into OneLake in Delta Lake table format. To keep the mirrored data efficiently stored and always ready for analytics, mirroring automatically runs vacuum to remove old files no longer referenced by a Delta log.
We now offer you the flexibility to customize the retention setting according to your requirements. For instance, you may choose a shorter retention period to reduce mirroring storage consumption or extend the retention period to utilize Delta’s time travel capabilities for analytics. Currently, this value can be set via API.
To learn more, refer to the retention for mirrored data documentation.
Mirroring region expansion
Mirroring now supports all regions that are available for workloads in Fabric. We have recently added a new region support for West US 3 to meet the growing customer demand. For detailed information about the Fabric regions that support mirroring, please refer to the supported Mirroring in Fabric regions documentation.
Alongside the region expansion for all Mirroring in Fabric, we are excited to announce that Mirroring for Azure PostgreSQL will also expand region support from the initial 4 regions: Canada Central, West Central US, East Asia, and North Europe to all regions supported by Mirroring in Microsoft Fabric to ensure that customers have the best performance when replicating data from Azure PostgreSQL flexible server.
To learn more, refer to Simplify Your Data Strategy: Mirroring for Azure Database for PostgreSQL in Microsoft Fabric for Effortless Analytics on Transactional Data.
Open Mirroring is now Generally Available
Lastly, we are so proud to announce that Open Mirroring is now generally available with parquet support! Open Mirroring is an extension of Mirroring capabilities in Fabric. Whether you’re a developer, data engineer, solution integrator, ISV, or business leader, Open Mirroring empowers you to build your own Mirroring solution while leveraging the same Mirroring engine to help you manage the complexity of making inserts/updates/deletes efficient and Fabric OneLake.
To learn more, please visit Announcing the General Availability of Open Mirroring.
Free Mirroring compute and storage for replicas in OneLake
The Fabric compute and OneLake storage up to a capacity-based limit are free for Database and Open Mirroring.
- Storage for replicas is free up to a limit based on the capacity size. Mirroring offers a free terabyte of mirroring storage for every capacity unit (CU) you have purchased.
- Mirroring compute in Fabric is free and does not consume capacity, it is used to replicate your data into Fabric OneLake.
To learn more details, refer to the Cost of Mirroring documentation.
Mirroring in Microsoft Fabric Roadmap
The Mirroring team continues to take your feedback into account as we continue to innovate with amazing features to make Mirroring in Microsoft Fabric the easiest way for you to bring your data estate into Microsoft Fabric.
We’ve made several exciting announcements today with the addition of Mirroring for SQL Server is now publicly available, new features that we have made publicly available in both Mirroring for Azure SQL MI and Cosmos DB, and Open Mirroring is now generally available. Many sources and features will be coming soon to further enhance Mirroring in Microsoft.
We look forward to hearing more of your ideas and what you need to run Mirroring in your production workload, please add your Fabric Ideas.
Stay tuned to our Mirroring Roadmap for all the new data sources and feature updates.
