ALTER REDACTION POLICY modifies a data redaction policy applied to a specified table.

Only the owner of the table to which the redaction policy is applied has the permission to modify the redaction policy.

Modify the expression used for a redaction policy to take effect.

ALTER REDACTION POLICY policy_name ON table_name WHEN (new_when_expression);

Enable or disable a redaction policy.

ALTER REDACTION POLICY policy_name ON table_name ENABLE | DISABLE;

Rename a redaction policy.

ALTER REDACTION POLICY policy_name ON table_name RENAME TO new_policy_name;

Add, modify, or delete a column on which the redaction policy is used.

ALTER REDACTION POLICY policy_name ON table_name 
    action;

There are several clauses of action:

ADD COLUMN column_name WITH function_name ( arguments )
  | MODIFY COLUMN column_name WITH function_name ( arguments )
  | DROP COLUMN column_name

policy_name
Specifies the name of the redaction policy to be modified.
table_name
Specifies the name of the table to which the redaction policy is applied.
new_when_expression
Specifies the new expression used for the redaction policy to take effect.
ENABLE | DISABLE
Specifies whether to enable or disable the current redaction policy.
- ENABLE
  Enables the redaction policy that was previously disabled for the table.
- DISABLE
  Disables the redaction policy currently applied to the table.
new_policy_name
Specifies the new name of the redaction policy.
column_name
Specifies the name of the table column to which the redaction policy is applied.

To add a column, use a column name that has not been bound to any redaction functions.

To modify a column, use the name of an existing column.

To delete a column, use the name of an existing column.
function_name
Specifies the name of a redaction function.
arguments
Specifies the list of arguments of the redaction function.

Modify the expression for the data redaction policy to take effect for all users.

ALTER REDACTION POLICY mask_emp ON emp WHEN (1=1);

Disable the redaction policy.

ALTER REDACTION POLICY mask_emp ON emp DISABLE;

Enable the redaction policy again.

ALTER REDACTION POLICY mask_emp ON emp ENABLE;

Change the redaction policy name to mask_emp_new.

ALTER REDACTION POLICY mask_emp ON emp RENAME TO mask_emp_new;

Add a column with the redaction policy used.

ALTER REDACTION POLICY mask_emp_new ON emp ADD COLUMN name WITH mask_partial(name, '*', 1, length(name));

Modify the redaction policy for the name column. Use the MASK_FULL function to redact all data in the name column.

ALTER REDACTION POLICY mask_emp_new ON emp MODIFY COLUMN name WITH mask_full(name);

Delete an existing column where the redaction policy is used.

ALTER REDACTION POLICY mask_emp_new ON emp DROP COLUMN name;