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Applies to: ✅ Warehouse in Microsoft Fabric
Microsoft Fabric offers the capability to create near-instantaneous zero-copy clones with minimal storage costs.
You can use the CREATE TABLE AS CLONE OF T-SQL commands to create a table clone. For a tutorial, see Tutorial: Clone table using T-SQL or Tutorial: Clone tables in the Fabric portal.
You can also query data in a warehouse as it appeared in the past, using the T-SQL OPTION
syntax. For more information, see Query data as it existed in the past.
A zero-copy clone creates a replica of the table by copying the metadata, while still referencing the same data files in OneLake. The metadata is copied while the underlying data of the table stored as parquet files is not copied. The creation of a clone is similar to creating a table within a Warehouse in Microsoft Fabric.
Within a warehouse, a clone of a table can be created near-instantaneously using simple T-SQL. A clone of a table can be created within or across schemas in a warehouse.
Clone of a table can be created based on either:
Current point-in-time: The clone is based on the present state of the table.
Previous point-in-time: The clone is based on a point-in-time up to thirty days in the past. The table clone contains the data as it appeared at a desired past point in time. In the industry, this feature is known as "time travel". The new table is created with a timestamp based on UTC. For examples, see Clone table as of past point-in-time or CREATE TABLE AS CLONE OF.
You can also clone a group of tables at once. This can be useful for cloning a group of related tables at the same past point in time. For an example, see Clone multiple tables at once.
You can also query data from tables as they existed in the past, using the Time travel feature in Warehouse.
Warehouse automatically preserves and maintains the data history for thirty calendar days, allowing for clones to be made at a point in time. All inserts, updates, and deletes made to the data warehouse are retained for thirty calendar days.
There is no limit on the number of clones created both within and across schemas.
Upon creation, a table clone is an independent and separate copy of the data from its source.
The following permissions are required to create a table clone:
Due to its autonomous existence, both the original source and the clones can be deleted without any constraints. Once a clone is created, it remains in existence until deleted by the user.
The objects described here are included in the table clone:
The clone table inherits object-level SQL security from the source table of the clone. As the workspace roles provide read access by default, DENY permission can be set on the table clone if desired.
The clone table inherits the row-level security (RLS) and dynamic data masking from the source of the clone table.
The clone table inherits all attributes that exist at the source table, whether the clone was created within the same schema or across different schemas in a warehouse.
The clone table inherits the primary and unique key constraints defined in the source table.
A read-only delta log is created for every table clone that is created within the Warehouse. The data files stored as delta parquet files are read-only. This ensures that the data stays always protected from corruption.
Consider the ability to clone tables near instantaneously and with minimal storage costs in the following beneficial scenarios:
Table clones allow developers and testers to experiment, validate, and refine the tables without affecting the tables in production environment. The clone provides a safe and isolated space to conduct development and testing activities of new features, ensuring the integrity and stability of the production environment. Use a table clone to quickly spin up a copy of production-like environment for troubleshooting, experimentation, development and testing purposes.
To keep up with the ever-changing data landscape, frequent execution of ETL jobs is essential. Table clones support this goal by ensuring data integrity while providing the flexibility to generate reports based on the cloned tables, while background processing is ongoing. Additionally, table clones enable the reproducibility of earlier results for machine learning models. They also facilitate valuable insights by enabling historical data exploration and analysis.
In the event of accidental data loss or corruption, existing table clones can be used to recover the table to its previous state.
For auditing or compliance purposes, zero copy clones can be easily used to create copies of data as it existed at a particular point in time in the past. Some data might need to be archived for long-term retention or legal compliance. Cloning the table at various historical points ensures that data is preserved in its original form.
Događaj
Steknite certifikat za Microsoft Fabric – besplatno!
19. stu 23 - 10. pro 23
Tim Microsoft Fabric Community na ograničeno vrijeme nudi besplatne vaučere za ispit DP-600.
Pripremite se sada