BLANK_COUNT (system data metric function)¶

Syntax¶

SNOWFLAKE.CORE.BLANK_COUNT(<query>)

Arguments¶

query

Specifies a SQL query on a table or view.

Allowed data types¶

The referenced column in the query must have the VARCHAR data type.

Returns¶

The function returns a NUMBER value.

Access control requirements¶

To use a system DMF, choose one of the following access control approaches:

• Grant the DATA_METRIC_USER database role to the table owner role, which is the role with the OWNERSHIP privilege on the table. This database role has the USAGE privilege on the SNOWFLAKE.CORE schema and the USAGE privilege on all system DMFs in the SNOWFLAKE.CORE schema.

  Additionally, grant the privileges in this table to the table owner role:

  Privilege	Object	Notes
  EXECUTE DATA METRIC FUNCTION	Account	This privilege enables you to control which roles have access to serverless compute resources to call the system DMF.
  USAGE	Database, schema	These objects are the database and schema that contain the referenced table in the query.

• Grant the privileges in the table to the table owner role and grant these privileges to the table owner role:

  • IMPORTED PRIVILEGES on the SNOWFLAKE database. For information, see Enabling other roles to use schemas in the SNOWFLAKE database.

• Use the ACCOUNTADMIN role.

For instructions on creating a custom role with a specified set of privileges, see Creating custom roles.

For general information about roles and privilege grants for performing SQL actions on securable objects, see Overview of Access Control.

Example¶

Measure the percentage of blank fields for the SSN column (US social security number):

SELECT SNOWFLAKE.CORE.BLANK_COUNT(
  SELECT
    ssn
  FROM hr.tables.empl_info
);

Copy

+-----------------------------------------------------------------+
| SNOWFLAKE.CORE.BLANK_COUNT(SELECT ssn FROM hr.tables.empl_info) |
+-----------------------------------------------------------------+
| 1                                                               |
+-----------------------------------------------------------------+