Provided by:
postgresql-client-8.0_8.0.7-2build1_i386 
NAME
GRANT - define access privileges
SYNOPSIS
GRANT { { SELECT | INSERT | UPDATE | DELETE | RULE | REFERENCES | TRIGGER }
[,...] | ALL [ PRIVILEGES ] }
ON [ TABLE ] tablename [, ...]
TO { username | GROUP groupname | PUBLIC } [, ...] [ WITH GRANT OPTION ]
GRANT { { CREATE | TEMPORARY | TEMP } [,...] | ALL [ PRIVILEGES ] }
ON DATABASE dbname [, ...]
TO { username | GROUP groupname | PUBLIC } [, ...] [ WITH GRANT OPTION ]
GRANT { EXECUTE | ALL [ PRIVILEGES ] }
ON FUNCTION funcname ([type, ...]) [, ...]
TO { username | GROUP groupname | PUBLIC } [, ...] [ WITH GRANT OPTION ]
GRANT { USAGE | ALL [ PRIVILEGES ] }
ON LANGUAGE langname [, ...]
TO { username | GROUP groupname | PUBLIC } [, ...] [ WITH GRANT OPTION ]
GRANT { { CREATE | USAGE } [,...] | ALL [ PRIVILEGES ] }
ON SCHEMA schemaname [, ...]
TO { username | GROUP groupname | PUBLIC } [, ...] [ WITH GRANT OPTION ]
GRANT { CREATE | ALL [ PRIVILEGES ] }
ON TABLESPACE tablespacename [, ...]
TO { username | GROUP groupname | PUBLIC } [, ...] [ WITH GRANT OPTION ]
DESCRIPTION
The GRANT command gives specific privileges on an object (table, view,
sequence, database, function, procedural language, schema, or
tablespace) to one or more users or groups of users. These privileges
are added to those already granted, if any.
The key word PUBLIC indicates that the privileges are to be granted to
all users, including those that may be created later. PUBLIC may be
thought of as an implicitly defined group that always includes all
users. Any particular user will have the sum of privileges granted
directly to him, privileges granted to any group he is presently a
member of, and privileges granted to PUBLIC.
If WITH GRANT OPTION is specified, the recipient of the privilege may
in turn grant it to others. Without a grant option, the recipient
cannot do that. At present, grant options can only be granted to
individual users, not to groups or 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 described by a grantable privilege; it is inherent in
the owner, and cannot be granted or revoked. The owner implicitly has
all grant options for the object, too.
Depending on the type of object, the initial default privileges may
include granting some privileges to PUBLIC. The default is no public
access for tables, schemas, and tablespaces; TEMP table creation
privilege for databases; EXECUTE privilege for functions; and USAGE
privilege for languages. The object owner may of course revoke these
privileges. (For maximum security, issue the REVOKE in the same
transaction that creates the object; then there is no window in which
another user may use the object.)
The possible privileges are:
SELECT Allows SELECT [select(7)] from any column of the specified
table, view, or sequence. Also allows the use of COPY [copy(7)]
TO. For sequences, this privilege also allows the use of the
currval function.
INSERT Allows INSERT [insert(7)] of a new row into the specified table.
Also allows COPY [copy(7)] FROM.
UPDATE Allows UPDATE [update(7)] of any column of the specified table.
SELECT ... FOR UPDATE also requires this privilege (besides the
SELECT privilege). For sequences, this privilege allows the use
of the nextval and setval functions.
DELETE Allows DELETE [delete(7)] of a row from the specified table.
RULE Allows the creation of a rule on the table/view. (See the CREATE
RULE [create_rule(7)] statement.)
REFERENCES
To create a foreign key constraint, it is necessary to have this
privilege on both the referencing and referenced tables.
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 and indexes 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.)
TEMPORARY
TEMP Allows temporary tables to be created while using the 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.
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.
NOTES
The REVOKE [revoke(7)] command is used to revoke access privileges.
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.
Currently, PostgreSQL does not support granting or revoking privileges
for individual columns of a table. One possible workaround is to
create a view having just the desired columns and then grant privileges
to that view.
Use psql(1)’s \z command to obtain information about existing
privileges, for example:
=> \z mytable
Access privileges for database "lusitania"
Schema | Name | Type | Access privileges
--------+---------+-------+------------------------------------------------------------
public | mytable | table | {miriam=arwdRxt/miriam,=r/miriam,"group todos=arw/miriam"}
(1 row)
The entries shown by \z are interpreted thus:
=xxxx -- privileges granted to PUBLIC
uname=xxxx -- privileges granted to a user
group gname=xxxx -- privileges granted to a group
r -- SELECT ("read")
w -- UPDATE ("write")
a -- INSERT ("append")
d -- DELETE
R -- RULE
x -- REFERENCES
t -- TRIGGER
X -- EXECUTE
U -- USAGE
C -- CREATE
T -- TEMPORARY
arwdRxt -- ALL PRIVILEGES (for tables)
* -- grant option for preceding privilege
/yyyy -- user who 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 GROUP todos;
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 may 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=arwdRxt/miriam}) and then modify them per the specified
request.
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.
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, and DELETE 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.
The SQL standard allows setting privileges for individual columns
within a table:
GRANT privileges
ON table [ ( column [, ...] ) ] [, ...]
TO { PUBLIC | username [, ...] } [ WITH GRANT OPTION ]
The SQL standard provides for a USAGE privilege on other kinds of
objects: character sets, collations, translations, domains.
The RULE privilege, and privileges on databases, tablespaces, schemas,
languages, and sequences are PostgreSQL extensions.
SEE ALSO
REVOKE [revoke(7)]