Forum Discussion
Mirroring vs Clone When we use these in fabric?
Hi,
We we use the Mirroring vs Clone in ms fabric to load the data?
What are advantages and disadvantages?
Thanks,
Sri
hi Koritala,
You can use mirroring n cloning depending on your aspect:
Aspect
Mirroring
Clone
Sync behavior
Continuous / near real‑time replication into OneLake
One‑time snapshot at creation (can also be point‑in‑time within retention for Warehouse tables)
Source
External operational systems (databases)
Warehouse tables in Fabric (zero‑copy clones)
Data freshness
Stays in sync with source (near real‑time)
Fixed at clone time (snapshot of that moment / chosen point)
Read / Write
Mirrored destination is read‑only for analytics consumption
Clone is a separate table; created by copying metadata while referencing same data files (zero‑copy)
ETL needed
No traditional ETL/pipelines required for replication
No ETL (metadata-only creation)
Best for
Live / near real‑time analytics on operational data
Dev/test, rollback safety, point‑in‑time reporting, reproducible experiments
Impact on source
Designed to offload analytics; replication managed by Fabric.
None on source system (it’s within Fabric Warehouse)
- Mirroring → when you want to bring data from external operational sources into Fabric/OneLake and keep it continuously (near real‑time) replicated for analytics consumption (typically read‑only in Fabric)
- Clone → this is specific to Fabric Warehouse tables: a zero‑copy table clone (snapshot) created within Fabric for dev/test, rollback, or point‑in‑time reporting—it copies metadata while referencing the same OneLake data files.
If it was helpful please mark it as a solution.
Thanks,
ShreyaHi Koritala ,
This is a great question.These are two very different features in Microsoft Fabric, each suited to different use cases.
Mirroring — Advantages & Disadvantages
Advantages--Faster time to insight with real-time data ingestion across multiple data sources and no ETL setup required, with a no-code approach.
--Mirroring gives you a simple and free way to mirror operational data into Fabric for analytics — it's optimized for ease of use with minimal setup.
--Storage used by the mirrored database is free, up to the number of terabytes of your Fabric capacity.
--Mirroring doesn't affect the performance or cost of the source database.Disadvantages
--You can mirror up to 1,000 tables (SQL Server) or 500 tables (Azure SQL DB, Snowflake) — tables above this limit cannot be replicated.
--Source tables using certain features (computed columns, user-defined types, LOB columns > 1MB, JSON/vector types) cannot be mirrored.
--Row-level security, dynamic data masking, and object-level permissions are not propagated to the mirrored data in OneLake.
--Latency might occur occasionally, and having too many copies can increase storage usage.
--Mirroring is read-only in OneLake — you cannot write back to the source.
--When capacity is paused, you are charged standard storage costs.Clone — Advantages & Disadvantages
Advantages--Table clones are created near-instantaneously with minimal storage costs, since only the metadata is copied while underlying data files are shared.
--Supports point-in-time cloning — you can clone a table as it existed up to 30 days in the past (time travel), which is useful for historical reporting and data recovery. Microsoft Learn
--Ideal for development, testing, and data recovery scenarios — developers can experiment without affecting production tables.
T--here is no limit on the number of clones created within or across schemas.Disadvantages
--Table clones across warehouses in a workspace are not currently supported, and cross-workspace clones are also not supported.
--Clone is not supported on the SQL analytics endpoint of the Lakehouse — only within a Warehouse.
--Once created, a clone is fully independent — any DML/DDL changes to the source are not reflected in the clone, and vice versa. This means it does not stay in sync (unlike Mirroring).
--Point-in-time history is limited to 30 days.If this post helps, then please appreciate giving a Kudos or accepting as a Solution to help the other members find it more quickly.Thanks a lot!
Hi Koritala,
I would also take a moment to thank ssrithar , Shreya_Barhate for actively participating in the community forum and for the solutions you’ve been sharing in the community forum. Your contributions make a real difference.
I wanted to check if you had the opportunity to review the information provided. Please feel free to contact us if you have any further questions.
Regards,
Community Support Team.
3 Replies
- Shreya_BarhateResolver II
hi Koritala,
You can use mirroring n cloning depending on your aspect:
Aspect
Mirroring
Clone
Sync behavior
Continuous / near real‑time replication into OneLake
One‑time snapshot at creation (can also be point‑in‑time within retention for Warehouse tables)
Source
External operational systems (databases)
Warehouse tables in Fabric (zero‑copy clones)
Data freshness
Stays in sync with source (near real‑time)
Fixed at clone time (snapshot of that moment / chosen point)
Read / Write
Mirrored destination is read‑only for analytics consumption
Clone is a separate table; created by copying metadata while referencing same data files (zero‑copy)
ETL needed
No traditional ETL/pipelines required for replication
No ETL (metadata-only creation)
Best for
Live / near real‑time analytics on operational data
Dev/test, rollback safety, point‑in‑time reporting, reproducible experiments
Impact on source
Designed to offload analytics; replication managed by Fabric.
None on source system (it’s within Fabric Warehouse)
- Mirroring → when you want to bring data from external operational sources into Fabric/OneLake and keep it continuously (near real‑time) replicated for analytics consumption (typically read‑only in Fabric)
- Clone → this is specific to Fabric Warehouse tables: a zero‑copy table clone (snapshot) created within Fabric for dev/test, rollback, or point‑in‑time reporting—it copies metadata while referencing the same OneLake data files.
If it was helpful please mark it as a solution.
Thanks,
Shreya - ssritharSuper User
Hi Koritala ,
This is a great question.These are two very different features in Microsoft Fabric, each suited to different use cases.
Mirroring — Advantages & Disadvantages
Advantages--Faster time to insight with real-time data ingestion across multiple data sources and no ETL setup required, with a no-code approach.
--Mirroring gives you a simple and free way to mirror operational data into Fabric for analytics — it's optimized for ease of use with minimal setup.
--Storage used by the mirrored database is free, up to the number of terabytes of your Fabric capacity.
--Mirroring doesn't affect the performance or cost of the source database.Disadvantages
--You can mirror up to 1,000 tables (SQL Server) or 500 tables (Azure SQL DB, Snowflake) — tables above this limit cannot be replicated.
--Source tables using certain features (computed columns, user-defined types, LOB columns > 1MB, JSON/vector types) cannot be mirrored.
--Row-level security, dynamic data masking, and object-level permissions are not propagated to the mirrored data in OneLake.
--Latency might occur occasionally, and having too many copies can increase storage usage.
--Mirroring is read-only in OneLake — you cannot write back to the source.
--When capacity is paused, you are charged standard storage costs.Clone — Advantages & Disadvantages
Advantages--Table clones are created near-instantaneously with minimal storage costs, since only the metadata is copied while underlying data files are shared.
--Supports point-in-time cloning — you can clone a table as it existed up to 30 days in the past (time travel), which is useful for historical reporting and data recovery. Microsoft Learn
--Ideal for development, testing, and data recovery scenarios — developers can experiment without affecting production tables.
T--here is no limit on the number of clones created within or across schemas.Disadvantages
--Table clones across warehouses in a workspace are not currently supported, and cross-workspace clones are also not supported.
--Clone is not supported on the SQL analytics endpoint of the Lakehouse — only within a Warehouse.
--Once created, a clone is fully independent — any DML/DDL changes to the source are not reflected in the clone, and vice versa. This means it does not stay in sync (unlike Mirroring).
--Point-in-time history is limited to 30 days.If this post helps, then please appreciate giving a Kudos or accepting as a Solution to help the other members find it more quickly.Thanks a lot!
- v-hjannapuCommunity Support
Hi Koritala,
I would also take a moment to thank ssrithar , Shreya_Barhate for actively participating in the community forum and for the solutions you’ve been sharing in the community forum. Your contributions make a real difference.
I wanted to check if you had the opportunity to review the information provided. Please feel free to contact us if you have any further questions.
Regards,
Community Support Team.