ALTER MASKING POLICY

Function

ALTER MASKING POLICY modifies anonymization policies.

Precautions

• Only user poladmin, user sysadmin, or the initial user can perform this operation.
• The masking policy takes effect only after enable_security_policy is set to on. For details about how to enable the masking policy, see "Database Configuration > Database Security Management Policies > Dynamic Data Masking" in the Security Hardening Guide.
• For details about the execution effect and supported data types of preset masking functions, see "Database Security > Dynamic Data Masking" in Feature Description.

Syntax

• Modify the policy description.

  1	ALTER MASKING POLICY policy_name COMMENTS policy_comments;

• Modify the anonymization method.

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  ALTER MASKING POLICY policy_name [ADD | REMOVE | MODIFY] masking_actions[, ...]*; The syntax of masking_action. masking_function ON LABEL(label_name[, ...]*)

• Modify the scenarios where the anonymization policies take effect.

  1	ALTER MASKING POLICY policy_name MODIFY(FILTER ON FILTER_TYPE(filter_value[, ...]*)[, ...]*);

• Removes the filters of the anonymization policies.

  1	ALTER MASKING POLICY policy_name DROP FILTER;

• Enable or disable the anonymization policies.

  1	ALTER MASKING POLICY policy_name [ENABLE | DISABLE];

Parameter Description

• policy_name

  Specifies the anonymization policy name, which must be unique.

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

• policy_comments

  Adds or modifies description of anonymization policies.

• masking_function

  Specifies eight preset anonymization methods or user-defined functions. Schema is supported.

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

  The preset anonymization methods are as follows:

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

• 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

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

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

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

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

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

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

-- Modify anonymization policy maskpol1 to add an anonymization method.
openGauss=# ALTER MASKING POLICY maskpol1 ADD randommasking ON LABEL(mask_lb2);

-- Modify anonymization policy maskpol1 to remove an anonymization method.
openGauss=# ALTER MASKING POLICY maskpol1 REMOVE randommasking ON LABEL(mask_lb2);

-- Modify anonymization policy maskpol1 to modify an anonymization method.
openGauss=# ALTER MASKING POLICY maskpol1 MODIFY randommasking ON LABEL(mask_lb1);

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

-- Disable anonymization policy maskpol1.
openGauss=# ALTER MASKING POLICY maskpol1 DISABLE;

Helpful Links

5.1.13.14.59-CREATE MASKING POLICY and 5.1.13.14.96-DROP MASKING POLICY