Provided by: postgresql-client-9.5_9.5.25-0ubuntu0.16.04.1_amd64 
NAME
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 function_name ( [ [ argmode ] [ arg_name ] arg_type [, ...] ] ) [, ...]
| ALL FUNCTIONS 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, 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.
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, and
functions (but note that ALL TABLES is considered to include views and foreign tables).
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 his 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.
PostgreSQL grants default privileges on some types of objects to PUBLIC. No privileges are
granted to PUBLIC by default on tables, table columns, sequences, foreign data wrappers,
foreign servers, large objects, schemas, or tablespaces. For other types of objects, the
default privileges granted to PUBLIC are as follows: CONNECT and TEMPORARY (create
temporary tables) privileges for databases; EXECUTE privilege for functions; and USAGE
privilege for languages and data types (including domains). The object owner can, of
course, REVOKE both default and expressly granted privileges. (For maximum security, issue
the REVOKE in the same transaction that creates the object; then there is no window in
which another user can use the object.) Also, these initial default privilege settings can
be changed using the ALTER DEFAULT PRIVILEGES (ALTER_DEFAULT_PRIVILEGES(7)) command.
The possible privileges are:
SELECT
Allows SELECT(7) from any column, or the specific columns listed, of the specified
table, view, or sequence. Also allows the use of COPY(7) TO. This privilege is also
needed to reference existing column values in UPDATE(7) or DELETE(7). For sequences,
this privilege also allows the use of the currval function. For large objects, this
privilege allows the object to be read.
INSERT
Allows INSERT(7) of a new row into the specified table. If specific columns are
listed, only those columns may be assigned to in the INSERT command (other columns
will therefore receive default values). Also allows COPY(7) FROM.
UPDATE
Allows UPDATE(7) of any column, or the specific columns listed, of the specified
table. (In practice, any nontrivial UPDATE command will require SELECT privilege as
well, since it must reference table columns to determine which rows to update, and/or
to compute new values for columns.) SELECT ... FOR UPDATE and SELECT ... FOR SHARE
also require this privilege on at least one column, in addition to the SELECT
privilege. For sequences, this privilege allows the use of the nextval and setval
functions. For large objects, this privilege allows writing or truncating the object.
DELETE
Allows DELETE(7) of a row from the specified table. (In practice, any nontrivial
DELETE command will require SELECT privilege as well, since it must reference table
columns to determine which rows to delete.)
TRUNCATE
Allows TRUNCATE(7) on the specified table.
REFERENCES
To create a foreign key constraint, it is necessary to have this privilege on both the
referencing and referenced columns. The privilege may be granted for all columns of a
table, or just specific columns.
TRIGGER
Allows the creation of a trigger on the specified table. (See the CREATE TRIGGER
(CREATE_TRIGGER(7)) statement.)
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 this privilege for the containing schema.
For tablespaces, allows tables, indexes, and temporary files to be created within the
tablespace, and allows databases to be created that have the tablespace as their
default tablespace. (Note that revoking this privilege will not alter the placement of
existing objects.)
CONNECT
Allows the user to connect to the specified database. This privilege is checked at
connection startup (in addition to checking any restrictions imposed by pg_hba.conf).
TEMPORARY
TEMP
Allows temporary tables to be created while using the specified database.
EXECUTE
Allows the use of the specified function and the use of any operators that are
implemented on top of the function. This is the only type of privilege that is
applicable to functions. (This syntax works for aggregate functions, as well.)
USAGE
For procedural languages, allows the use of the specified language for the creation of
functions in that language. This is the only type of privilege that is applicable to
procedural languages.
For schemas, allows access to objects contained in the specified schema (assuming that
the objects' own privilege requirements are also met). Essentially this allows the
grantee to “look up” objects within the schema. Without this permission, it is still
possible to see the object names, e.g., by querying the system tables. Also, after
revoking this permission, existing backends might have statements that have previously
performed this lookup, so this is not a completely secure way to prevent object
access.
For sequences, this privilege allows the use of the currval and nextval functions.
For types and domains, this privilege allow the use of the type or domain in the
creation of tables, functions, and other schema objects. (Note that it does not
control general “usage” of the type, such as values of the type appearing in queries.
It only prevents objects from being created that depend on the type. The main purpose
of the privilege is controlling which users create dependencies on a type, which could
prevent the owner from changing the type later.)
For foreign-data wrappers, this privilege enables the grantee to create new servers
using that foreign-data wrapper.
For servers, this privilege enables the grantee to create foreign tables using the
server, and also to create, alter, or drop his own user's user mappings associated
with that server.
ALL PRIVILEGES
Grant all of the available privileges at once. The PRIVILEGES key word is optional in
PostgreSQL, though it is required by strict SQL.
The privileges required by other commands are listed on the reference page of the
respective command.
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(7) 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 he holds 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 you 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.
Use psql(1)'s \dp command to obtain information about existing privileges for tables and
columns. For example:
=> \dp mytable
Access privileges
Schema | Name | Type | Access privileges | Column access privileges
--------+---------+-------+-----------------------+--------------------------
public | mytable | table | miriam=arwdDxt/miriam | col1:
: =r/miriam : miriam_rw=rw/miriam
: admin=arw/miriam
(1 row)
The entries shown by \dp are interpreted thus:
rolename=xxxx -- privileges granted to a role
=xxxx -- privileges granted to PUBLIC
r -- SELECT ("read")
w -- UPDATE ("write")
a -- INSERT ("append")
d -- DELETE
D -- TRUNCATE
x -- REFERENCES
t -- TRIGGER
X -- EXECUTE
U -- USAGE
C -- CREATE
c -- CONNECT
T -- TEMPORARY
arwdDxt -- ALL PRIVILEGES (for tables, varies for other objects)
* -- grant option for preceding privilege
/yyyy -- role that granted this privilege
The above example display would be seen by user miriam after creating table mytable and
doing:
GRANT SELECT ON mytable TO PUBLIC;
GRANT SELECT, UPDATE, INSERT ON mytable TO admin;
GRANT SELECT (col1), UPDATE (col1) ON mytable TO miriam_rw;
For non-table objects there are other \d commands that can display their privileges.
If the “Access privileges” column is empty for a given object, it means the object has
default privileges (that is, its privileges column is null). Default privileges always
include all privileges for the owner, and can include some privileges for PUBLIC depending
on the object type, as explained above. The first GRANT or REVOKE on an object will
instantiate the default privileges (producing, for example, {miriam=arwdDxt/miriam}) and
then modify them per the specified request. Similarly, entries are shown in “Column access
privileges” only for columns with nondefault privileges. (Note: for this purpose, “default
privileges” always means the built-in default privileges for the object's type. An object
whose privileges have been affected by an ALTER DEFAULT PRIVILEGES command will always be
shown with an explicit privilege entry that includes the effects of the ALTER.)
Notice that the owner's implicit grant options are not marked in the access privileges
display. A * will appear only when grant options have been explicitly granted to someone.
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 his own ordinary privileges: for example, a
table owner can make the table read-only to himself by revoking his 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 himself; therefore he 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.
SEE ALSO
REVOKE(7), ALTER DEFAULT PRIVILEGES (ALTER_DEFAULT_PRIVILEGES(7))