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

-- 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;

Related

• Information schema

• CATALOGS

• COLUMNS

• ROUTINES