Help Center> GaussDB> Distributed_8.x> SQL Reference> SQL Syntax> A> ALTER ROW LEVEL SECURITY POLICY
Updated on 2024-06-03 GMT+08:00

ALTER ROW LEVEL SECURITY POLICY

Description

Modifies an existing row-level security policy, including the policy name and the users and expressions affected by the policy.

Precautions

Only the table owner or a system administrator can perform this operation.

Syntax

  • Change the name of an existing row-level security policy.
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    ALTER [ ROW LEVEL SECURITY ] POLICY policy_name ON table_name RENAME TO new_policy_name;
    

  • Change the specified user and policy expression of an existing row-level security policy.
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    ALTER [ ROW LEVEL SECURITY ] POLICY policy_name ON table_name
        [ TO { role_name | PUBLIC } [, ...] ]
        [ USING ( using_expression ) ];
    

Parameters

  • policy_name

    Specifies the name of a row-level security policy.

  • table_name

    Specifies the name of a table to which a row-level security policy is applied.

  • new_policy_name

    Specifies the new name of a row-level security policy.

  • role_name

    Specifies names of users affected by a row-level security policy. PUBLIC indicates that the row-level security policy will affect all users.

  • using_expression

    Specifies a row-level security policy, which is similar to a Boolean expression in the WHERE clause.

Examples

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-- Create the data table all_data.
gaussdb=# CREATE TABLE all_data(id int, role varchar(100), data varchar(100));

-- Create a row-level security policy to specify that the current user can view only their own data.
gaussdb=# CREATE ROW LEVEL SECURITY POLICY all_data_rls ON all_data USING(role = CURRENT_USER);
gaussdb=# \d+ all_data
                               Table "public.all_data"
 Column |          Type          | Modifiers | Storage  | Stats target | Description
--------+------------------------+-----------+----------+--------------+-------------
 id     | integer                |           | plain    |              |
 role   | character varying(100) |           | extended |              |
 data   | character varying(100) |           | extended |              |
Row Level Security Policies:
    POLICY "all_data_rls" FOR ALL
      TO public
      USING (((role)::name = "current_user"()))
Has OIDs: no
Distribute By: HASH(id)
Location Nodes: ALL DATANODES
Options: orientation=row, compression=no

-- Change the name of the all_data_rls policy.
gaussdb=# ALTER ROW LEVEL SECURITY POLICY all_data_rls ON all_data RENAME TO all_data_new_rls;

-- Create users alice and bob.
gaussdb=# CREATE ROLE alice WITH PASSWORD "********";
gaussdb=# CREATE ROLE bob WITH PASSWORD "********";

-- Change the users affected by the row-level security policy.
gaussdb=# ALTER ROW LEVEL SECURITY POLICY all_data_new_rls ON all_data TO alice, bob;
gaussdb=# \d+ all_data
                               Table "public.all_data"
 Column |          Type          | Modifiers | Storage  | Stats target | Description
--------+------------------------+-----------+----------+--------------+-------------
 id     | integer                |           | plain    |              |
 role   | character varying(100) |           | extended |              |
 data   | character varying(100) |           | extended |              |
Row Level Security Policies:
    POLICY "all_data_new_rls" FOR ALL
      TO alice,bob
      USING (((role)::name = "current_user"()))
Has OIDs: no
Distribute By: HASH(id)
Location Nodes: ALL DATANODES
Options: orientation=row, compression=no, enable_rowsecurity=true

-- Modify the expression defined for the row-level security policy.
gaussdb=# ALTER ROW LEVEL SECURITY POLICY all_data_new_rls ON all_data USING (id > 100 AND role = current_user);
gaussdb=# \d+ all_data
                               Table "public.all_data"
 Column |          Type          | Modifiers | Storage  | Stats target | Description
--------+------------------------+-----------+----------+--------------+-------------
 id     | integer                |           | plain    |              |
 role   | character varying(100) |           | extended |              |
 data   | character varying(100) |           | extended |              |
Row Level Security Policies:
    POLICY "all_data_new_rls" FOR ALL
      TO alice,bob
      USING (((id > 100) AND ((role)::name = "current_user"())))
Has OIDs: no
Distribute By: HASH(id)
Location Nodes: ALL DATANODES
Options: orientation=row, compression=no, enable_rowsecurity=true

-- Delete the policy.
gaussdb=# DROP ROW LEVEL SECURITY POLICY all_data_new_rls ON all_data;

-- Delete users alice and bob.
gaussdb=# DROP ROLE alice, bob;

-- Delete the all_data table.
gaussdb=# DROP TABLE all_data;