GRANT

Function

GRANT grants permissions to roles and users.

The GRANT statement has the following variants:

  • Granting system permissions to roles or users

    System permissions are also called user properties, including SYSADMIN, CREATEDB, CREATEROLE, AUDITADMIN, MONADMIN, OPRADMIN, POLADMIN, and LOGIN.

    They can be specified only by the CREATE ROLE or ALTER ROLE statement. The SYSADMIN permissions can be granted and revoked using GRANT ALL PRIVILEGE and REVOKE ALL PRIVILEGE, respectively. System permissions cannot be inherited by a user from a role, and cannot be granted using PUBLIC.

  • Granting database object permissions to roles or users

    Grant permissions on a database object (table, view, column, database, function, schema, or tablespace) to a role or user.

    GRANT gives specific permissions on a database object to one or more roles. These permissions are added to those already granted, if any.

    The keyword PUBLIC indicates that the permissions are to be granted to all roles, including those that might be created later. PUBLIC can be thought of as an implicitly defined group that always includes all roles. Any particular role will have the sum of permissions granted directly to it, permissions granted to any role it is presently a member of, and permissions granted to PUBLIC.

    If WITH GRANT OPTION is specified, the recipient of the permission can in turn grant it to others. Without a grant option, the recipient cannot do that. GRANT options cannot be granted to PUBLIC. Only openGauss supports this operation.

    openGauss grants the permissions for objects of certain types to PUBLIC. By default, permissions on tables, columns, sequences, foreign data sources, foreign servers, schemas, and tablespaces are not granted to PUBLIC, but the following permissions are granted to PUBLIC: CONNECT and CREATE TEMP TABLE permissions on databases, EXECUTE permission on functions, and USAGE permission on languages and data types (including domains). An object owner can revoke the default permissions granted to PUBLIC and grant permissions to other users as needed. For security purposes, you are advised to create an object and set its permissions in the same transaction so that other users do not have time windows to use the object. In addition, you can restrict the permissions of the PUBLIC user group by referring to t"Permission Management" in Security Hardening Guide. These default permissions can be modified using the ALTER DEFAULT PRIVILEGES command.

    By default, an object owner has all permissions on the object. For security purposes, the owner can discard some permissions. However, the ALTER, DROP, COMMENT, INDEX, VACUUM, and re-grantable permissions of the object are inherent permissions implicitly owned by the owner.

  • Granting the permissions of one role or user to others

    Grant the permissions of one role or user to others. In this case, every role or user can be regarded as a set of one or more database permissions.

    If WITH ADMIN OPTION is specified, the recipients can in turn grant the permissions to other roles or users or revoke the permissions they have granted to other roles or users. If recipients' permissions are changed or revoked later, the grantees' permissions will also change.

    Database administrators can grant or revoke permissions for any roles or users. Roles with the CREATEROLE permission can grant or revoke permissions for non-admin roles.

Precautions

None

Syntax

  • Grant the table or view access permission to a user or role.

    GRANT { { SELECT | INSERT | UPDATE | DELETE | TRUNCATE | REFERENCES | ALTER | DROP | COMMENT | INDEX | VACUUM } [, ...] 
          | ALL [ PRIVILEGES ] }
        ON { [ TABLE ] table_name [, ...]
           | ALL TABLES IN SCHEMA schema_name [, ...] }
        TO { [ GROUP ] role_name | PUBLIC } [, ...] 
        [ WITH GRANT OPTION ];
    
  • Grant the column access permission to a user or role.

    GRANT { {{ SELECT | INSERT | UPDATE | REFERENCES | COMMENT } ( column_name [, ...] )} [, ...] 
          | ALL [ PRIVILEGES ] ( column_name [, ...] ) }
        ON [ TABLE ] table_name [, ...]
        TO { [ GROUP ] role_name | PUBLIC } [, ...]
        [ WITH GRANT OPTION ];
    
  • Grant the sequence access permission to a specified user or role.

    GRANT { { SELECT | UPDATE | USAGE | ALTER | DROP | COMMENT } [, ...] 
          | ALL [ PRIVILEGES ] }
        ON { [ SEQUENCE ] sequence_name [, ...]
           | ALL SEQUENCES IN SCHEMA schema_name [, ...] }
        TO { [ GROUP ] role_name | PUBLIC } [, ...] 
        [ WITH GRANT OPTION ];
    
  • Grant the database access permission to a user or role.

    GRANT { { CREATE | CONNECT | TEMPORARY | TEMP | ALTER | DROP | COMMENT } [, ...]
          | ALL [ PRIVILEGES ] }
        ON DATABASE database_name [, ...]
        TO { [ GROUP ] role_name | PUBLIC } [, ...]
        [ WITH GRANT OPTION ];
    
  • Grant the domain access permission to a user or role.

    GRANT { USAGE | ALL [ PRIVILEGES ] }
        ON DOMAIN domain_name [, ...]
        TO { [ GROUP ] role_name | PUBLIC } [, ...]
        [ WITH GRANT OPTION ];
    

    NOTE: In the current version, the domain access permission cannot be granted.

  • Grant the client master key (CMK) access permission to a specified user or role.

    GRANT { USAGE | DROP | ALL [ PRIVILEGES ] }
        ON { CLIENT_MASTER_KEY client_master_key [, ...]
        TO { [ GROUP ] role_name | PUBLIC } [, ...] 
        [ WITH GRANT OPTION ];
    
  • Grant the column encryption key (CEK) access permission to a specified user or role.

    GRANT { USAGE | DROP| ALL [ PRIVILEGES ] }
        ON { COLUMN_ENCRYPTION_KEY column_encryption_key [, ...]
        TO { [ GROUP ] role_name | PUBLIC } [, ...] 
        [ WITH GRANT OPTION ];
    
  • Grant the foreign data source access permission to a user or role.

    GRANT { USAGE | ALL [ PRIVILEGES ] }
        ON FOREIGN DATA WRAPPER fdw_name [, ...]
        TO { [ GROUP ] role_name | PUBLIC } [, ...]
        [ WITH GRANT OPTION ];
    
  • Grant the foreign server access permission to a user or role.

    GRANT { { USAGE | ALTER | DROP | COMMENT } [, ...] | ALL [ PRIVILEGES ] }
        ON FOREIGN SERVER server_name [, ...]
        TO { [ GROUP ] role_name | PUBLIC } [, ...]
        [ WITH GRANT OPTION ];
    
  • Grant the function access permission to a user or role.

    GRANT { { EXECUTE | ALTER | DROP | COMMENT } [, ...] | ALL [ PRIVILEGES ] }
        ON { FUNCTION {function_name ( [ {[ argmode ] [ arg_name ] arg_type} [, ...] ] )} [, ...]
           | ALL FUNCTIONS IN SCHEMA schema_name [, ...] }
        TO { [ GROUP ] role_name | PUBLIC } [, ...]
        [ WITH GRANT OPTION ];
    
  • Grant the procedural language access permission to a user or role.

    GRANT { USAGE | ALL [ PRIVILEGES ] }
        ON LANGUAGE lang_name [, ...]
        TO { [ GROUP ] role_name | PUBLIC } [, ...]
        [ WITH GRANT OPTION ];
    
  • Grant the large object access permission to a specified user or role.

    GRANT { { SELECT | UPDATE } [, ...] | ALL [ PRIVILEGES ] }
        ON LARGE OBJECT loid [, ...]
        TO { [ GROUP ] role_name | PUBLIC } [, ...]
        [ WITH GRANT OPTION ];
    

    NOTE: The current version does not support granting the large object access permission.

  • Grant the schema access permission to a user or role.

    GRANT { { CREATE | USAGE | ALTER | DROP | COMMENT } [, ...] | ALL [ PRIVILEGES ] }
        ON SCHEMA schema_name [, ...]
        TO { [ GROUP ] role_name | PUBLIC } [, ...]
        [ WITH GRANT OPTION ];
    

    NOTE: When granting table or view permissions to other users, you also need to grant the USAGE permission on the containing schema. Without the USAGE permission, the recipients can only see the object names, but cannot access them.

  • Grant the tablespace access permission to a user or role.

    GRANT { { CREATE | ALTER | DROP | COMMENT } [, ...] | ALL [ PRIVILEGES ] }
        ON TABLESPACE tablespace_name [, ...]
        TO { [ GROUP ] role_name | PUBLIC } [, ...]
        [ WITH GRANT OPTION ];
    
  • Grant the type access permission to a user or role.

    GRANT { { USAGE | ALTER | DROP | COMMENT } [, ...] | ALL [ PRIVILEGES ] }
        ON TYPE type_name [, ...]
        TO { [ GROUP ] role_name | PUBLIC } [, ...]
        [ WITH GRANT OPTION ];
    

    NOTE: In the current version, the type access permission cannot be granted.

  • Grant a role's permissions to another user or role.

    GRANT role_name [, ...]
       TO role_name [, ...]
       [ WITH ADMIN OPTION ];
    
  • Grant the sysadmin permission to a role.

    GRANT ALL { PRIVILEGES | PRIVILEGE }
       TO role_name;
    
  • Grant the data source permission to a role.

    GRANT {USAGE | ALL [PRIVILEGES]}
       ON DATA SOURCE src_name [, ...]
       TO {[GROUP] role_name | PUBLIC} [, ...] [WITH GRANT OPTION];
    
  • Grant the directory permission to a role.

    GRANT {READ|WRITE| ALL [PRIVILEGES]}
       ON DIRECTORY directory_name [, ...]
       TO {[GROUP] role_name | PUBLIC} [, ...] [WITH GRANT OPTION];
    

Parameter Description

The possible permissions are:

  • SELECT

    Allows SELECT from any column, or the specific columns listed, of the specified table, view, or sequence. The SELECT permission on the corresponding field is also required for UPDATE or DELETE.

  • INSERT

    Allows INSERT of a new row into a table.

  • UPDATE

    Allows UPDATE of any column of a table. Generally, UPDATE also requires the SELECT permission to query which rows need to be updated. SELECT … FOR UPDATE and SELECT … FOR SHARE also require this permission on at least one column, in addition to the SELECT permission.

  • DELETE

    Allows DELETE of a row from a table. Generally, DELETE also requires the SELECT permission to query which rows need to be deleted.

  • TRUNCATE

    Allows TRUNCATE on a table.

  • REFERENCES

    Allows creation of a foreign key constraint referencing a table. This permission is required on both referencing and referenced tables.

  • CREATE

    • For databases, allows new schemas to be created within the database.
    • For schemas, allows new objects to be created within the schema. To rename an existing object, you must own the object and have the CREATE permission on the schema of the object.
    • For tablespaces, allows tables to be created within the tablespace, and allows databases and schemas to be created that have the tablespace as their default tablespace.
  • CONNECT

    Allows the grantee to connect to the database.

  • EXECUTE

    Allows calling a function, including use of any operators that are implemented on top of the function.

  • USAGE

    • For procedural languages, allows use of the language for the creation of functions in that language.
    • For schemas, allows access to objects contained in the schema. Without this permission, it is still possible to see the object names.
    • For sequences, allows use of the nextval function.
    • For data sources, specifies access permissions or is used as ALL PRIVILEGES.
  • ALTER

    Allows users to modify properties of a specified object, excluding the owner and schema of the object.

  • DROP

    Allows users to delete specified objects.

  • COMMENT

    Allows users to define or modify comments of a specified object.

  • INDEX

    Allows users to create indexes on specified tables, manage indexes on the tables, and perform REINDEX and CLUSTER operations on the tables.

  • VACUUM

    Allows users to perform ANALYZE and VACUUM operations on specified tables.

  • ALL PRIVILEGES

    Grants all available permissions to a user or role at a time. Only a system administrator has the GRANT ALL PRIVILEGES permission.

GRANT parameters are as follows:

  • role_name

    Specifies the username.

  • table_name

    Specifies the table name.

  • column_name

    Specifies the column name.

  • schema_name

    Specifies the schema name.

  • database_name

    Specifies the database name.

  • funcation_name

    Specifies the function name.

  • sequence_name

    Specifies the sequence name.

  • domain_name

    Specifies the domain type name.

  • fdw_name

    Specifies the foreign data wrapper name.

  • lang_name

    Specifies the language name.

  • type_name

    Specifies the type name.

  • src_name

    Specifies the data source name.

  • argmode

    Specifies the parameter mode.

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

  • arg_name

    Specifies the parameter name.

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

  • arg_type

    Specifies the parameter type.

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

  • loid

    Specifies the identifier of the large object that includes this page.

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

  • tablespace_name

    Specifies the tablespace name.

  • client_master_key

    Name of the client master key.

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

  • column_encryption_key

    Name of the column encryption key.

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

  • directory_name

    Specifies the directory name.

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

  • WITH GRANT OPTION

    If WITH GRANT OPTION is specified, the recipient of the permission can in turn grant it to others. Without a grant option, the recipient cannot do that. Grant options cannot be granted to PUBLIC.

When a non-owner of an object attempts to GRANT permissions on the object:

  • The statement will fail outright if the user has no permissions whatsoever on the object.
  • As long as some permission is available, the statement will proceed, but it will grant only those permissions for which the user has grant options.
  • The GRANT ALL PRIVILEGES forms will issue a warning message if no grant options are held, while the other forms will issue a warning if grant options for any of the permissions specifically named in the statement are not held.

NOTE: Database administrators can access all objects, regardless of object permission settings. This is comparable to the permissions of root in a Unix system. As with root, it is unwise to operate as a system administrator except when necessary. GRANT to a table partition will cause alarms.

Examples

Example 1: Granting system permissions to a user or role

Create the joe user and grant the sysadmin permissions to it.

postgres=# CREATE USER joe PASSWORD 'xxxxxxxxx';
postgres=# GRANT ALL PRIVILEGES TO joe;

Then joe has the sysadmin permission.

Example 2: Granting object permissions to a user or role

  1. Revoke the sysadmin permission from the joe user. Grant the usage permission of the tpcds schema and all permissions on the tpcds.reason table to joe.

    postgres=# REVOKE ALL PRIVILEGES FROM joe;
    postgres=# GRANT USAGE ON SCHEMA tpcds TO joe;
    postgres=# GRANT ALL PRIVILEGES ON tpcds.reason TO joe;
    

    Then joe has all permissions on the tpcds.reason table, including create, retrieve, update, and delete.

  2. Grant the retrieve permission of r_reason_sk, r_reason_id, and r_reason_desc columns and the update permission of the r_reason_desc column in the tpcds.reason table to joe.

    postgres=# GRANT select (r_reason_sk,r_reason_id,r_reason_desc),update (r_reason_desc) ON tpcds.reason TO joe;
    

    Then joe has the retrieve permission of r_reason_sk and r_reason_id columns in the tpcds.reason table. To enable joe to grant these permissions to other users, execute the following statement:

    postgres=# GRANT select (r_reason_sk, r_reason_id) ON tpcds.reason TO joe WITH GRANT OPTION;
    

    Grant the connection and schema creation permissions of the postgres database to joe, and allow joe to grant these permissions to other users.

    postgres=# GRANT create,connect on database postgres TO joe WITH GRANT OPTION;
    

    Create the tpcds_manager role, grant the access and object creation permissions of the tpcds schema to tpcds_manager, but do not allow tpcds_manager to grant these permissions to others.

    postgres=# CREATE ROLE tpcds_manager PASSWORD 'xxxxxxxxx';
    postgres=# GRANT USAGE,CREATE ON SCHEMA tpcds TO tpcds_manager;
    

    Grant all permissions on the tpcds_tbspc tablespace to joe, but do not allow joe to grant these permissions to others.

    postgres=# CREATE TABLESPACE tpcds_tbspc RELATIVE LOCATION 'tablespace/tablespace_1';
    postgres=# GRANT ALL ON TABLESPACE tpcds_tbspc TO joe;
    

Example 3: Granting the permissions of one user or role to others

  1. Create the manager role, grant joe's permissions to manager, and allow manager to grant these permissions to others.

    postgres=# CREATE ROLE manager PASSWORD 'xxxxxxxxx';
    postgres=# GRANT joe TO manager WITH ADMIN OPTION;
    
  2. Create the senior_manager user and grant manager's permissions to it.

    postgres=# CREATE ROLE senior_manager PASSWORD 'xxxxxxxxx';
    postgres=# GRANT manager TO senior_manager;
    
  3. Revoke permissions and delete users.

    postgres=# REVOKE manager FROM joe;
    postgres=# REVOKE senior_manager FROM manager;
    postgres=# DROP USER manager;
    

Example: Granting the CMK or CEK permission to other user or role

  1. Connect to an encrypted database.

    gsql -p 57101 postgres -r -C
    postgres=#  CREATE CLIENT MASTER KEY MyCMK1 WITH ( KEY_STORE = localkms , KEY_PATH = "key_path_value" , ALGORITHM = RSA_2048);
    CREATE CLIENT MASTER KEY
    postgres=# CREATE COLUMN ENCRYPTION KEY MyCEK1 WITH VALUES (CLIENT_MASTER_KEY = MyCMK1, ALGORITHM = AEAD_AES_256_CBC_HMAC_SHA256);
    CREATE COLUMN ENCRYPTION KEY
    
  2. Create a role **newuser **and grant the key permission to newuser.

    postgres=# CREATE USER newuser PASSWORD 'xxxxxxxxx';
    CREATE ROLE
    postgres=# GRANT ALL ON SCHEMA public TO newuser;
    GRANT
    postgres=# GRANT USAGE ON COLUMN_ENCRYPTION_KEY MyCEK1 to newuser;
    GRANT
    postgres=# GRANT USAGE ON CLIENT_MASTER_KEY MyCMK1 to newuser;
    GRANT
    
  3. Set the user to connect to a database and use a CEK to create an encrypted table.

    postgres=# SET SESSION AUTHORIZATION newuser PASSWORD 'xxxxxxxxx';
    postgres=>  CREATE TABLE acltest1 (x int, x2 varchar(50) ENCRYPTED WITH (COLUMN_ENCRYPTION_KEY = MyCEK1, ENCRYPTION_TYPE = DETERMINISTIC));
    CREATE TABLE
    postgres=> SELECT has_cek_privilege('newuser', 'MyCEK1', 'USAGE');
     has_cek_privilege
    -------------------
     t
    (1 row)
    
  4. Revoke permissions and delete users.

    postgres=# REVOKE USAGE ON COLUMN_ENCRYPTION_KEY MyCEK1 FROM newuser;
    postgres=# REVOKE USAGE ON CLIENT_MASTER_KEY MyCMK1 FROM newuser;
    postgres=# DROP TABLE newuser.acltest1;
    postgres=# DROP COLUMN ENCRYPTION KEY MyCEK1;
    postgres=# DROP CLIENT MASTER KEY MyCMK1;
    postgres=# DROP SCHEMA IF EXISTS newuser CASCADE;
    postgres=# REVOKE ALL ON SCHEMA public FROM newuser;
    postgres=# DROP ROLE IF EXISTS newuser;
    

Example 4: Revoking permissions and deleting roles and users

postgres=# REVOKE ALL PRIVILEGES ON tpcds.reason FROM joe;
postgres=# REVOKE ALL PRIVILEGES ON SCHEMA tpcds FROM joe;
postgres=# REVOKE ALL ON TABLESPACE tpcds_tbspc FROM joe;
postgres=# DROP TABLESPACE tpcds_tbspc;
postgres=# REVOKE USAGE,CREATE ON SCHEMA tpcds FROM tpcds_manager;
postgres=# DROP ROLE tpcds_manager;
postgres=# DROP ROLE senior_manager;
postgres=# DROP USER joe CASCADE;

Helpful Links

REVOKE and ALTER DEFAULT PRIVILEGES

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2024-02-28 06:33:58
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