Create OneLake shortcuts in a KQL database

OneLake is a single, unified, logical data lake for Microsoft Fabric to store lakehouses, warehouses, KQL databases, and other items. Shortcuts are embedded references within OneLake that point to other files' store locations without moving the original data. The embedded reference makes it appear as though the files and folders are stored locally but in reality; they exist in another storage location. Shortcuts can be updated or removed from your items, but these changes don't affect the original data and its source.

In this article, you learn how to create a OneLake shortcut in a KQL database that points to internal Fabric or external sources. This kind of shortcut is later accessed for query in KQL querysets by using the external_table() function. Shortcuts created in a KQL database can't be renamed, and only one shortcut can be created at a time.

In addition to creating shortcuts from a KQL database, shortcuts can also be created from other Fabric items. These shortcuts also point to data stored in internal Fabric or external sources, but have different limitations and are accessed differently. For more information, see OneLake shortcuts.

Prerequisites

• A workspace with a Microsoft Fabric-enabled capacity
• A KQL database with editing permissions
• A Lakehouse

To access the data in your KQL database in other Microsoft Fabric experiences, see One logical copy.

Create shortcut

1. Browse to an existing KQL database.

2. Select + > New > OneLake shortcut.

   

Select a source

OneLake supports shortcuts to both internal OneLake resources (like KQL databases, lakehouses, and warehouses) and external resources (like Azure Data Lake Storage, Amazon S3, or Google Cloud Storage). For a list of all supported shortcut types and links to their specific configuration instructions, see OneLake shortcuts > Types of shortcuts.

Shortcuts in KQL databases support query acceleration. To enable query acceleration on a new shortcut, toggle the Accelerate button to On.

After you create a shortcut, the database refreshes automatically. The shortcut appears under Shortcuts in the Explorer pane. You can now query this data.

Query data

To query data from the OneLake shortcut, use the external_table() function.

1. On the rightmost side of your database, select Explore your data. The window opens with a few example queries you can run to get an initial look at your data.
2. Replace the table name placeholder with external_table('Shortcut name').
3. Select Run or press Shift + Enter to run a selected query.

Data types mapping

Delta parquet to Eventhouse data types mapping

Delta primitive data types are mapped to Eventhouse scalar data types using the following rules. For more information on Eventhouse data types, see Scalar data types.

Related content

• Query data in a KQL queryset
• external_table() function
• Accelerate queries over OneLake shortcuts