COLUMN_MASKS
Databricks Runtime 12.2 LTS and above Unity Catalog only.
Preview
This feature is in Public Preview.
INFORMATION_SCHEMA.COLUMN_MASKS contains the column masking metadata for table columns in the catalog, or all catalogs if owned by the SYSTEM catalog.
Information is displayed only for columns the user has permission to interact with.
This relation is an extension to the SQL Standard Information Schema.
Definition
The COLUMN_MASKS relation contains the following.
| Name | Data type | Nullable | Description |
|---|---|---|---|
CATALOG_NAME | STRING | No | Catalog that contains the table. |
SCHEMA_NAME | STRING | No | Schema that contains the table. |
TABLE_NAME | STRING | No | Name of the table the column is part of. |
COLUMN_NAME | STRING | No | The column that the masks applies to. |
MASK_CATALOG | STRING | No | Catalog that contains the mask function. |
MASK_SCHEMA | STRING | No | Schema that contains the mask function. |
MASK_NAME | STRING | No | The specific name of the function implementing the mask. |
MASK_COL_USAGE | STRING | Yes | A comma separated list of additional columns passed to the masking function. NULL if none. |
Constraints
The following constraint applies to the COLUMN_TAGS relation:
| Class | Name | Column List | Description |
|---|---|---|---|
| Primary key | COLUMN_MASKS_PK | CATALOG_NAME, SCHEMA_NAME, TABLE_NAME, COLUMN_NAME | Unique identifier for a column mask. |
| Foreign key | COLUMN_MASKS_COLUMNS_FK | CATALOG_NAME, SCHEMA_NAME, TABLE_NAME, COLUMN_NAME | References COLUMNS |
| Foreign key | COLUMN_MASKS_ROUTINES_FK | MASK_CATALOG, MASK_SCHEMA, MASK_NAME | References ROUTINES |
Example
SQL
-- Return the names of all functions used as column masks in the current catalog.
> SELECT mask_catalog, mask_schema, mask_name, count(1)
FROM information_schema.column_masks
GROUP BY ALL
ORDER BY ALL;