Tutorial: Lakehouse shortcut editor¶
CSA Loom
lakehouse-shortcuteditor — the Azure-native equivalent of a Microsoft Fabric OneLake shortcut: a named pointer to external Delta/Parquet that a lakehouse reads in place without copying. Built on ADLS Gen2 with no OneLake / Fabric dependency.
What it is¶
A shortcut is a named pointer to external data that a lakehouse reads in place — no bytes are copied. Loom persists the pointer as a workspace item: a connector made of a source type, non-secret coordinates, and (for credentialed sources) a Key Vault secretRef. On create and on verify, Loom lists one level of the target to prove the pointer resolves, then SQL / Spark over the lakehouse reads the shortcut's Delta / Parquet directly at query time.
When to use it¶
- You want to query external Delta/Parquet (in ADLS, Blob, S3, GCS, or a Dataverse Synapse Link export) alongside your lakehouse tables without an ETL copy.
- You want a governed, named reference to another team's data location instead of duplicating it.
- You are migrating OneLake-shortcut patterns to an Azure-native lake.
Step-by-step in Loom¶
- Open the editor. Choose + New item → Lakehouse shortcut (Data Engineering). The editor opens at
/items/lakehouse-shortcut/<id>. - Name the shortcut. Give it a name; it appears under the lakehouse's shortcuts as a virtual folder.
- Pick a source type. Choose one of the parity sources — internal lakehouse-to-lakehouse, external ADLS Gen2 / Blob (optional SAS), Amazon S3 / S3-compatible (MinIO / Wasabi), Google Cloud Storage, or Dataverse (Synapse Link export path).
- Enter the coordinates. Provide the container + path (or bucket + region), and for credentialed sources a key that Loom stores in Key Vault — only a
secretRefis persisted in Cosmos, never the secret itself. - Verify resolution. Loom lists the target path via the source's real client (ADLS / S3 SigV4 / GCS JWT→OAuth / Dataverse) to confirm the pointer resolves — proving access without copying a single byte.
- Query in place. Spark or Synapse serverless SQL over the lakehouse reads the shortcut's Delta / Parquet directly at query time; the data is never duplicated.
The Azure backend it rides on¶
- Lake: the existing DLZ ADLS Gen2 account (
LOOM_ADLS_ACCOUNT,LOOM_BRONZE/SILVER/GOLD_URL) — no new infrastructure to deploy. - Credentials (external sources): Azure Key Vault (
LOOM_SHORTCUT_KEYVAULT/LOOM_KEY_VAULT_URI) holds S3 / GCS / SAS secrets; Cosmos stores only thesecretRef. - RBAC: the Console UAMI's Storage Blob Data Reader/Contributor on the DLZ account (internal + external ADLS) and Key Vault Secrets Officer on the shortcut vault (credentialed sources).
No Fabric required¶
The shortcut is a pure ADLS Gen2 external-location pointer resolved to an abfss:// path — no OneLake, no Fabric capacity or workspace. When no ADLS account / medallion URL is configured, verify/create returns a precise message naming the missing LOOM_*_URL container rather than failing silently.
Learn more¶
- Parity notes:
../parity/lakehouse-shortcut.md - Lakehouse editor tutorial:
editor-lakehouse.md - OneLake shortcuts (source concept): https://learn.microsoft.com/fabric/onelake/onelake-shortcuts
- ADLS Gen2: https://learn.microsoft.com/azure/storage/blobs/data-lake-storage-introduction