ALTER MASKING POLICY

Function

ALTER MASKING POLICY modifies masking policies.

Precautions

• Only users with the poladmin or sysadmin permission, or the initial user can perform this operation.
• The masking policy takes effect only after enable_security_policy is set to on.

Syntax

• Modify the policy description.

  AlterMaskingPolicy ::= ALTER MASKING POLICY policy_name COMMENTS policy_comments;

• Modify the masking method.

  AlterMaskingPolicy ::= ALTER MASKING POLICY policy_name [ADD | REMOVE | MODIFY] masking_actions[, ...];

  The syntax of masking_action.

  masking_action ::= masking_function ON LABEL ( label_name[, ...] )

• Modify the scenarios where the anonymization policies take effect.

  AlterMaskingPolicy ::= ALTER MASKING POLICY policy_name MODIFY ( FILTER ON { FILTER_TYPE ( filter_value [, ...] ) } [, ...] );

• Removes the filters of the masking policies.

  AlterMaskingPolicy ::= ALTER MASKING POLICY policy_name DROP FILTER;

• Enable or disable the masking policies.

  AlterMaskingPolicy ::= ALTER MASKING POLICY policy_name [ENABLE | DISABLE];

Parameter Description

• policy_name

  Specifies the masking policy name, which must be unique.

  Value range: a string. It must comply with the naming convention.

• policy_comments

  Adds or modifies description of masking policies.

• masking_function

  Specifies eight preset masking methods or user-defined functions. Schemas are supported.

  maskall is not a preset function. It is hard-coded and cannot be displayed by running \df.

  The masking methods during presetting are as follows:

  maskall | randommasking | creditcardmasking | basicemailmasking | fullemailmasking | shufflemasking | alldigitsmasking | regexpmasking

• label_name

  Specifies the resource label name.

• FILTER_TYPE

  Specifies the types of information to be filtered by the policies: IP, ROLES, and APP.

• filter_value

  Indicates the detailed information to be filtered, such as the IP address, app name, and username.

• ENABLE|DISABLE

  Enables or disables the masking policy. If ENABLE|DISABLE is not specified, ENABLE is used by default.

Examples

-- Create users dev_mask and bob_mask.
MogDB=# CREATE USER dev_mask PASSWORD 'dev@1234';
MogDB=# CREATE USER bob_mask PASSWORD 'bob@1234';

-- Create table tb_for_masking.
MogDB=# CREATE TABLE tb_for_masking(col1 text, col2 text, col3 text);

-- Create a resource label for label sensitive column col1.
MogDB=# CREATE RESOURCE LABEL mask_lb1 ADD COLUMN(tb_for_masking.col1);

-- Create a resource label for label sensitive column col2.
MogDB=# CREATE RESOURCE LABEL mask_lb2 ADD COLUMN(tb_for_masking.col2);

-- Create a masking policy for the operation of accessing sensitive column col1.
MogDB=# CREATE MASKING POLICY maskpol1 maskall ON LABEL(mask_lb1);

-- Add description for masking policy maskpol1.
MogDB=# ALTER MASKING POLICY maskpol1 COMMENTS 'masking policy for tb_for_masking.col1';

-- Modify masking policy maskpol1 to add a masking method.
MogDB=# ALTER MASKING POLICY maskpol1 ADD randommasking ON LABEL(mask_lb2);

-- Modify masking policy maskpol1 to remove a masking method.
MogDB=# ALTER MASKING POLICY maskpol1 REMOVE randommasking ON LABEL(mask_lb2);

-- Modify masking policy maskpol1 to modify a masking method.
MogDB=# ALTER MASKING POLICY maskpol1 MODIFY randommasking ON LABEL(mask_lb1);

-- Modify masking policy maskpol1 so that it takes effect only for scenarios where users are dev_mask and bob_mask, client tools are psql and gsql, and the IP addresses are 10.20.30.40 and 127.0.0.0/24.
MogDB=# ALTER MASKING POLICY maskpol1 MODIFY (FILTER ON ROLES(dev_mask, bob_mask), APP(psql, gsql), IP('10.20.30.40', '127.0.0.0/24'));

-- Modify masking policy maskpol1 so that it takes effect for all user scenarios.
MogDB=# ALTER MASKING POLICY maskpol1 DROP FILTER;

-- Disable masking policy maskpol1.
MogDB=# ALTER MASKING POLICY maskpol1 DISABLE;

Helpful Links

CREATE MASKING POLICY, DROP MASKING POLICY.