Snowflake Semantic View Extraction (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 Snowflake Semantic View extraction, ensure that you have completed the following:

  1. Met the connector requirements.

  2. Enabled the feature.

  3. Granted the required permissions.

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.

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

No additional permissions are required beyond standard Metadata Extraction (MDE) access:

  • SHOW SEMANTIC VIEWS IN DATABASE requires USAGE on the database (same as MDE).

  • SYSTEM$READ_YAML_FROM_SEMANTIC_VIEW() requires SELECT on the Semantic View (granted to the PUBLIC role by default).

If the PUBLIC role’s SELECT privilege has been revoked, grant the following permissions:

-- Replace <database> with the actual database name
-- Replace <alation_role> with your Alation service account role

GRANT SELECT ON ALL SEMANTIC VIEWS IN DATABASE <database> TO ROLE <alation_role>;
GRANT SELECT ON FUTURE SEMANTIC VIEWS IN DATABASE <database> TO ROLE <alation_role>;

Configuration

Enable Semantic View Extraction

  1. Go to the Settings page of your Snowflake data source.

  2. In the Metadata Extraction tab, go to the Customize extraction scope (optional) section.

  3. 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

  1. Go to the Metadata Extraction tab of your Snowflake data source.

  2. Click Run extraction. For detailed information, see Configure Metadata Extraction.

After extraction completes, the Semantic Views will be 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 also applied to Semantic Views. The connector extracts only those Semantic Views in schemas that match the configured filter.

Limitations

  • Alation does not support global search for Semantic Views. Semantic Models are accessible through the catalog but may not appear in global search results.

  • Semantic Views must be available in your Snowflake account. This is a Snowflake feature that may not be available on all account types.

  • Semantic Views that fail to parse are skipped with a warning, and extraction continues for the remaining views.

Troubleshooting

Extract Semantic Views Toggle Is Unavailable

Problem

The Extract Semantic Views toggle is not appearing under the Customize extraction scope section.

Cause

The feature has not been enabled on your Alation instance.

Solution

Contact connectors@alation.com to have the feature enabled. This feature is available only on Alation Cloud Service deployments.

Extraction Completes Without Any Semantic Models Appearing in the Catalog

Problem

Metadata extraction completes successfully but no Semantic Models appear in the catalog.

Cause

No Semantic Views exist in the selected schemas, or schema filters exclude all schemas containing Semantic Views.

Solution

  1. Verify Semantic Views exist in your Snowflake account:

    SHOW SEMANTIC VIEWS IN DATABASE <database>;

  2. 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 SELECT privilege on the Semantic View has been revoked from the PUBLIC role.

Solution

Grant SELECT on Semantic Views to the service account role:

GRANT SELECT ON ALL SEMANTIC VIEWS IN DATABASE <database> TO ROLE <alation_role>;
GRANT SELECT ON FUTURE SEMANTIC VIEWS IN DATABASE <database> TO ROLE <alation_role>;

For additional troubleshooting, see Troubleshooting.