GRANT
GRANT
GRANT - define access privileges
Synopsis
GRANT { { SELECT | INSERT | UPDATE | DELETE | TRUNCATE | REFERENCES | TRIGGER }
[, ...] | ALL [ PRIVILEGES ] }
ON { [ TABLE ] table_name [, ...]
| ALL TABLES IN SCHEMA schema_name [, ...] }
TO role_specification [, ...] [ WITH GRANT OPTION ]
GRANT { { SELECT | INSERT | UPDATE | REFERENCES } ( column_name [, ...] )
[, ...] | ALL [ PRIVILEGES ] ( column_name [, ...] ) }
ON [ TABLE ] table_name [, ...]
TO role_specification [, ...] [ WITH GRANT OPTION ]
GRANT { { USAGE | SELECT | UPDATE }
[, ...] | ALL [ PRIVILEGES ] }
ON { SEQUENCE sequence_name [, ...]
| ALL SEQUENCES IN SCHEMA schema_name [, ...] }
TO role_specification [, ...] [ WITH GRANT OPTION ]
GRANT { { CREATE | CONNECT | TEMPORARY | TEMP } [, ...] | ALL [ PRIVILEGES ] }
ON DATABASE database_name [, ...]
TO role_specification [, ...] [ WITH GRANT OPTION ]
GRANT { USAGE | ALL [ PRIVILEGES ] }
ON DOMAIN domain_name [, ...]
TO role_specification [, ...] [ WITH GRANT OPTION ]
GRANT { USAGE | ALL [ PRIVILEGES ] }
ON FOREIGN DATA WRAPPER fdw_name [, ...]
TO role_specification [, ...] [ WITH GRANT OPTION ]
GRANT { USAGE | ALL [ PRIVILEGES ] }
ON FOREIGN SERVER server_name [, ...]
TO role_specification [, ...] [ WITH GRANT OPTION ]
GRANT { EXECUTE | ALL [ PRIVILEGES ] }
ON { { FUNCTION | PROCEDURE | ROUTINE } routine_name [ ( [ [ argmode ] [ arg_name ] arg_type [, ...] ] ) ] [, ...]
| ALL { FUNCTIONS | PROCEDURES | ROUTINES } IN SCHEMA schema_name [, ...] }
TO role_specification [, ...] [ WITH GRANT OPTION ]
GRANT { USAGE | ALL [ PRIVILEGES ] }
ON LANGUAGE lang_name [, ...]
TO role_specification [, ...] [ WITH GRANT OPTION ]
GRANT { { SELECT | UPDATE } [, ...] | ALL [ PRIVILEGES ] }
ON LARGE OBJECT loid [, ...]
TO role_specification [, ...] [ WITH GRANT OPTION ]
GRANT { { CREATE | USAGE } [, ...] | ALL [ PRIVILEGES ] }
ON SCHEMA schema_name [, ...]
TO role_specification [, ...] [ WITH GRANT OPTION ]
GRANT { CREATE | ALL [ PRIVILEGES ] }
ON TABLESPACE tablespace_name [, ...]
TO role_specification [, ...] [ WITH GRANT OPTION ]
GRANT { USAGE | ALL [ PRIVILEGES ] }
ON TYPE type_name [, ...]
TO role_specification [, ...] [ WITH GRANT OPTION ]
GRANT role_name [, ...] TO role_specification [, ...]
[ WITH ADMIN OPTION ]
[ GRANTED BY role_specification ]
where role_specification can be:
[ GROUP ] role_name
| PUBLIC
| CURRENT_USER
| SESSION_USER
Description
The
GRANT
command has two basic variants: one
that grants privileges on a database object (table, column, view, foreign
table, sequence, database, foreign-data wrapper, foreign server, function, procedure,
procedural language, schema, or tablespace), and one that grants
membership in a role. These variants are similar in many ways, but
they are different enough to be described separately.
GRANT on Database Objects
This variant of the
GRANT
command gives specific
privileges on a database object to
one or more roles. These privileges are added
to those already granted, if any.
The key word
PUBLIC
indicates that the
privileges 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 privileges granted directly to it, privileges granted to any role it
is presently a member of, and privileges granted to
PUBLIC
.
If
WITH GRANT OPTION
is specified, the recipient
of the privilege can in turn grant it to others. Without a grant
option, the recipient cannot do that. Grant options cannot be granted
to
PUBLIC
.
There is no need to grant privileges to the owner of an object (usually the user that created it), as the owner has all privileges by default. (The owner could, however, choose to revoke some of their own privileges for safety.)
The right to drop an object, or to alter its definition in any way, is not treated as a grantable privilege; it is inherent in the owner, and cannot be granted or revoked. (However, a similar effect can be obtained by granting or revoking membership in the role that owns the object; see below.) The owner implicitly has all grant options for the object, too.
The possible privileges are:
-
SELECT
INSERT
UPDATE
DELETE
TRUNCATE
REFERENCES
TRIGGER
CREATE
CONNECT
TEMPORARY
EXECUTE
USAGE -
Specific types of privileges, as defined in Section 5.7 .
-
TEMP -
Alternative spelling for
TEMPORARY. -
ALL PRIVILEGES -
Grant all of the privileges available for the object's type. The
PRIVILEGESkey word is optional in PostgreSQL , though it is required by strict SQL.
The
FUNCTION
syntax works for plain functions,
aggregate functions, and window functions, but not for procedures;
use
PROCEDURE
for those.
Alternatively, use
ROUTINE
to refer to a function,
aggregate function, window function, or procedure regardless of its
precise type.
There is also an option to grant privileges on all objects of the same
type within one or more schemas. This functionality is currently supported
only for tables, sequences, functions, and procedures.
ALL
TABLES
also affects views and foreign tables, just like the
specific-object
GRANT
command.
ALL
FUNCTIONS
also affects aggregate and window functions, but not
procedures, again just like the specific-object
GRANT
command. Use
ALL ROUTINES
to include procedures.
GRANT on Roles
This variant of the
GRANT
command grants membership
in a role to one or more other roles. Membership in a role is significant
because it conveys the privileges granted to a role to each of its
members.
If
WITH ADMIN OPTION
is specified, the member can
in turn grant membership in the role to others, and revoke membership
in the role as well. Without the admin option, ordinary users cannot
do that. A role is not considered to hold
WITH ADMIN
OPTION
on itself, but it may grant or revoke membership in
itself from a database session where the session user matches the
role. Database superusers can grant or revoke membership in any role
to anyone. Roles having
CREATEROLE
privilege can grant
or revoke membership in any role that is not a superuser.
If
GRANTED BY
is specified, the grant is recorded as
having been done by the specified role. Only database superusers may
use this option, except when it names the same role executing the command.
Unlike the case with privileges, membership in a role cannot be granted
to
PUBLIC
. Note also that this form of the command
does not allow the noise word
GROUP
in
role_specification
.
Notes
The REVOKE command is used to revoke access privileges.
Since
PostgreSQL
8.1, the concepts of users and
groups have been unified into a single kind of entity called a role.
It is therefore no longer necessary to use the keyword
GROUP
to identify whether a grantee is a user or a group.
GROUP
is still allowed in the command, but it is a noise word.
A user may perform
SELECT
,
INSERT
, etc. on a
column if they hold that privilege for either the specific column or
its whole table. Granting the privilege at the table level and then
revoking it for one column will not do what one might wish: the
table-level grant is unaffected by a column-level operation.
When a non-owner of an object attempts to
GRANT
privileges
on the object, the command will fail outright if the user has no
privileges whatsoever on the object. As long as some privilege is
available, the command will proceed, but it will grant only those
privileges 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 privileges specifically named in the command are not held.
(In principle these statements apply to the object owner as well, but
since the owner is always treated as holding all grant options, the
cases can never occur.)
It should be noted that database superusers can access
all objects regardless of object privilege settings. This
is comparable to the rights of
root
in a Unix system.
As with
root
, it's unwise to operate as a superuser
except when absolutely necessary.
If a superuser chooses to issue a
GRANT
or
REVOKE
command, the command is performed as though it were issued by the
owner of the affected object. In particular, privileges granted via
such a command will appear to have been granted by the object owner.
(For role membership, the membership appears to have been granted
by the containing role itself.)
GRANT
and
REVOKE
can also be done by a role
that is not the owner of the affected object, but is a member of the role
that owns the object, or is a member of a role that holds privileges
WITH GRANT OPTION
on the object. In this case the
privileges will be recorded as having been granted by the role that
actually owns the object or holds the privileges
WITH GRANT OPTION
. For example, if table
t1
is owned by role
g1
, of which role
u1
is a member, then
u1
can grant privileges
on
t1
to
u2
, but those privileges will appear
to have been granted directly by
g1
. Any other member
of role
g1
could revoke them later.
If the role executing
GRANT
holds the required privileges
indirectly via more than one role membership path, it is unspecified
which containing role will be recorded as having done the grant. In such
cases it is best practice to use
SET ROLE
to become the
specific role you want to do the
GRANT
as.
Granting permission on a table does not automatically extend
permissions to any sequences used by the table, including
sequences tied to
SERIAL
columns. Permissions on
sequences must be set separately.
See Section 5.7 for more information about specific privilege types, as well as how to inspect objects' privileges.
Examples
Grant insert privilege to all users on table
films
:
GRANT INSERT ON films TO PUBLIC;
Grant all available privileges to user
manuel
on view
kinds
:
GRANT ALL PRIVILEGES ON kinds TO manuel;
Note that while the above will indeed grant all privileges if executed by a
superuser or the owner of
kinds
, when executed by someone
else it will only grant those permissions for which the someone else has
grant options.
Grant membership in role
admins
to user
joe
:
GRANT admins TO joe;
Compatibility
According to the SQL standard, the
PRIVILEGES
key word in
ALL PRIVILEGES
is required. The
SQL standard does not support setting the privileges on more than
one object per command.
PostgreSQL
allows an object owner to revoke their
own ordinary privileges: for example, a table owner can make the table
read-only to themselves by revoking their own
INSERT
,
UPDATE
,
DELETE
, and
TRUNCATE
privileges. This is not possible according to the SQL standard. The
reason is that
PostgreSQL
treats the owner's
privileges as having been granted by the owner to themselves; therefore they
can revoke them too. In the SQL standard, the owner's privileges are
granted by an assumed entity
"
_SYSTEM
"
. Not being
"
_SYSTEM
"
, the owner cannot revoke these rights.
According to the SQL standard, grant options can be granted to
PUBLIC
; PostgreSQL only supports granting grant options
to roles.
The SQL standard allows the
GRANTED BY
option to
be used in all forms of
GRANT
. PostgreSQL only
supports it when granting role membership, and even then only superusers
may use it in nontrivial ways.
The SQL standard provides for a
USAGE
privilege
on other kinds of objects: character sets, collations,
translations.
In the SQL standard, sequences only have a
USAGE
privilege, which controls the use of the
NEXT VALUE FOR
expression, which is equivalent to the
function
nextval
in PostgreSQL. The sequence
privileges
SELECT
and
UPDATE
are
PostgreSQL extensions. The application of the
sequence
USAGE
privilege to
the
currval
function is also a PostgreSQL extension (as
is the function itself).
Privileges on databases, tablespaces, schemas, and languages are PostgreSQL extensions.