How to Retrieve Masked Column Information in Unity Catalog

[jv_v]

Hi all,

I’ve been working with Unity Catalog in Databricks and using column masking policies for sensitive fields like SSNs. While trying to retrieve metadata about which columns have masking policies applied, I ran into some challenges and wanted to share my findings + get input from the community.

✅ Tried Approaches

1. DESCRIBE EXTENDED <table>
   This shows masking policies applied on individual columns under the "Comment" or "Metadata" fields — but it’s not structured and hard to automate for large-scale scans.

2. <catalog>.information_schema.column_masks
   Surprisingly, this view is empty in some client environments — even when I know masking policies are in place and functional. I'm assuming it could be due to:

   • Delayed metadata sync

   • Lack of permissions

   • Feature not fully available in that workspace

❓ Looking for a Better Way

Aside from DESCRIBE EXTENDED and the information schema view:

• Is there a more reliable way to programmatically retrieve which columns have masking policies applied?

• Does anyone have experience using Databricks REST API?

• Any internal Unity Catalog system tables or best practices for scanning a catalog/schema and reporting masked fields?

Would appreciate any guidance, alternate approaches, or scripts you’ve found useful in your projects.

Thanks in advance!
—Vyshnavi

[niteshm]

@jv_v 
There are a few more approaches that you can try which are ideal for large scale scanning, 

Try using, Unity Catalog System Tables via system.information_schema Instead of <catalog>.information_schema.column_masks

If that doesnt work, use Databricks REST API, GET /api/2.1/unity-catalog/tables/{full_name}.

Reference.: Get a table | Tables API | REST API reference | Databricks on AWS