SET ROLE
SQL - Language Statements
SET ROLE
set the current user identifier of the current session
SET ROLE
SET [ SESSION | LOCAL ] ROLE rolename
SET [ SESSION | LOCAL ] ROLE NONE
RESET ROLE
Description
This command sets the current user
identifier of the current SQL-session context to be rolename. The role name can be
written as either an identifier or a string literal.
After SET ROLE>, permissions checking for SQL commands
is carried out as though the named role were the one that had logged
in originally.
The specified rolename
must be a role that the current session user is a member of.
(If the session user is a superuser, any role can be selected.)
The SESSION> and LOCAL> modifiers act the same
as for the regular
command.
The NONE> and RESET> forms reset the current
user identifier to be the current session user identifier.
These forms can be executed by any user.
Notes
Using this command, it is possible to either add privileges or restrict
one's privileges. If the session user role has the INHERITS>
attribute, then it automatically has all the privileges of every role that
it could SET ROLE> to; in this case SET ROLE>
effectively drops all the privileges assigned directly to the session user
and to the other roles it is a member of, leaving only the privileges
available to the named role. On the other hand, if the session user role
has the NOINHERITS> attribute, SET ROLE> drops the
privileges assigned directly to the session user and instead acquires the
privileges available to the named role.
In particular, when a superuser chooses to SET ROLE> to a
non-superuser role, she loses her superuser privileges.
SET ROLE> has effects comparable to
, but the privilege
checks involved are quite different. Also,
SET SESSION AUTHORIZATION> determines which roles are
allowable for later SET ROLE> commands, whereas changing
roles with SET ROLE> does not change the set of roles
allowed to a later SET ROLE>.
Examples
SELECT SESSION_USER, CURRENT_USER;
session_user | current_user
--------------+--------------
peter | peter
SET ROLE 'paul';
SELECT SESSION_USER, CURRENT_USER;
session_user | current_user
--------------+--------------
peter | paul
Compatibility
PostgreSQL
allows identifier syntax ("rolename"), while
the SQL standard requires the role name to be written as a string
literal. SQL does not allow this command during a transaction;
PostgreSQL does not make this
restriction because there is no reason to.
The SESSION> and LOCAL> modifiers are a
PostgreSQL extension, as is the
RESET> syntax.
See Also