Extract Semantic Views from Snowflake (Beta)¶
Alation Cloud Service Applies to Alation Cloud Service instances of Alation
Available from Alation version 2026.5.1 and Snowflake OCF Connector version 2.12.0.
Note
This feature is currently in Beta. Contact connectors@alation.com for installation and enablement.
Snowflake semantic views provide a declarative, YAML-based way to define business semantics (dimensions, metrics, relationships) on top of physical tables. They enable organizations to create a governed semantic layer that standardizes how data is queried and interpreted.
The Snowflake OCF connector can discover and extract semantic views, ingesting them as semantic models in the Alation catalog. This enables complete visibility into your semantic layer for governance and discovery.
Prerequisites¶
Before configuring semantic view extraction, ensure that you have completed the following:
Connector Requirements¶
Ensure that:
The Snowflake OCF connector version is 2.12.0 or higher.
The Alation version is 2026.5.1 or higher.
The deployment type is Alation Cloud Service.
Semantic views are available in your Snowflake account. This is a Snowflake feature that may not be available on all account types.
For complete prerequisite information, see Prerequisites.
Feature Enablement¶
This feature requires server-side enablement. Contact connectors@alation.com to have this feature enabled on your instance.
Service Account Permissions¶
In addition to the standard MDE permissions (USAGE on the database and schema), the Alation service account role requires SELECT on each semantic view to read its YAML definition via SYSTEM$READ_YAML_FROM_SEMANTIC_VIEW().
Grant the following additional permissions to the Alation service account role:
-- Replace <database> with the actual database name
-- Replace <schema> with the schema name
-- Replace <alation_role> with your Alation service account role
GRANT SELECT ON ALL SEMANTIC VIEWS IN SCHEMA <database>.<schema> TO ROLE <alation_role>;
GRANT SELECT ON FUTURE SEMANTIC VIEWS IN SCHEMA <database>.<schema> TO ROLE <alation_role>;
The FUTURE grant ensures that newly created semantic views are automatically accessible to the connector without requiring additional grants.
Note
If your organization has already granted SELECT on semantic views to the PUBLIC role, these explicit grants are not required since all roles inherit PUBLIC privileges.
Configuration¶
Enable Semantic View Extraction¶
Go to the Settings page of your Snowflake data source.
In the Metadata Extraction tab, go to the Customize extraction scope (optional) section.
Turn on the Extract Semantic Views toggle.
Note
The Extract Semantic Views toggle is only visible when the feature has been enabled on your instance. Contact connectors@alation.com if you do not see this toggle.
Perform Metadata Extraction¶
Go to the Metadata Extraction tab of your Snowflake data source.
Click Run extraction. For detailed information, see Configure Metadata Extraction.
After extraction completes, semantic views are cataloged as semantic models in Alation with their datasets, fields, metrics, and relationships.
What is Extracted¶
When extraction completes, the following semantic model components are cataloged in Alation:
Semantic model: name, description, and full definition of the semantic view.
Datasets: logical tables defined in the semantic view, mapped to their underlying physical tables.
Dimensions: dimension fields (including time dimensions) with their expressions and data types.
Facts / Measures: measure fields with their expressions and aggregation types.
Metrics: calculated metrics, both table-scoped and model-scoped.
Relationships: join relationships between datasets with column mappings.
Schema Filtering¶
Schema filters configured in Alation (include or exclude) are applied to semantic views. The connector extracts only those semantic views that belong to schemas matching the configured filter.
Limitations¶
Semantic models extracted from semantic views are not indexed by Alation’s full-page search or Ask Alation. They are accessible only from their parent schema catalog page.
Semantic views that fail to parse are skipped and a warning is logged in the extraction job log. Extraction continues for the remaining views.
Troubleshooting¶
Extraction Completes Without Any Semantic Models Appearing in the Catalog¶
Problem¶
Metadata extraction completes successfully but no semantic models appear in the catalog.
Cause¶
The Extract Semantic Views toggle is not enabled.
No semantic views exist in the selected schemas.
Schema filters exclude all schemas containing semantic views.
Solution¶
Verify that the Extract Semantic Views toggle is enabled under Customize extraction scope.
Verify semantic views exist in your Snowflake account:
SHOW SEMANTIC VIEWS IN DATABASE <database>;
Check the schema include/exclude filters configured on the data source to ensure the relevant schemas are included.
Not All Semantic Views Are Extracted¶
Problem¶
Some semantic views are not extracted while others succeed.
Cause¶
The service account role does not have SELECT privilege on the missing semantic views.
Solution¶
Grant SELECT on semantic views to the service account role:
GRANT SELECT ON ALL SEMANTIC VIEWS IN SCHEMA <database>.<schema> TO ROLE <alation_role>;
GRANT SELECT ON FUTURE SEMANTIC VIEWS IN SCHEMA <database>.<schema> TO ROLE <alation_role>;
For additional troubleshooting, see Troubleshooting.