Data Policies are Not Extracted into Policy Center

Customer Managed Applies to customer-managed instances of Alation

Problem

After the metadata extraction from a Snowflake data source in Alation, the extraction job history shows the status Success in the Alation user interface, but the new data policy objects are not extracted and do not appear in Policy Center. Previously, the data policy objects were extracted successfully.

The taskserver.log file contains an error message similar to the following:

"exception_class":"net.snowflake.client.jdbc.SnowflakeSQLException",
"exception_message":"SQL compilation error:\nObject does not exist,
or operation cannot be performed."

Root Cause

There were changes to the INFORMATION_SCHEMA.POLICY_REFERENCES table function in the Snowflake schema. It is likely that these changes were released by Snowflake after you set up data policy extraction views. These changes prevent the new data policy objects to be extracted and require that the view METADATA_DB.METADATA_SCHEMA.POLICY_REFERENCES should be recreated. For more details, see POLICY_REFERENCES Function: New Columns in Snowflake knowledge base.

Solution

Recreate the view METADATA_DB.METADATA_SCHEMA.POLICY_REFERENCES set up on Snowflake for data policy extraction:

1. On your Snowflake database, recreate the view using the following query:

   CREATE OR REPLACE VIEW METADATA_DB.METADATA_SCHEMA.POLICY_REFERENCES
     AS SELECT POLICY_DB,
                     POLICY_SCHEMA,
                     POLICY_ID,
                     POLICY_NAME,
                     POLICY_KIND,
                     REF_DATABASE_NAME,
                     REF_SCHEMA_NAME,
                     REF_ENTITY_NAME,
                     REF_ENTITY_DOMAIN,
                     REF_COLUMN_NAME,
                     REF_ARG_COLUMN_NAMES
     FROM SNOWFLAKE.ACCOUNT_USAGE.POLICY_REFERENCES;
   

2. Grant the Alation service role access to the recreated policy view. Replace <alation_role> in the SQL below with your actual Alation service account role name.

   GRANT SELECT ON METADATA_DB.METADATA_SCHEMA.POLICY_REFERENCES
   TO <alation_role>;
   

3. Rerun metadata extraction for your Snowflake data source in Alation. Now, data policy objects should be extracted and displayed in Policy Center.

   Note

   Refer to Snowflake for details about setting up Snowflake data sources in Alation.