SET ROLE — set the current user identifier of the current session
SET [ SESSION | LOCAL ] ROLE role_name
SET [ SESSION | LOCAL ] ROLE NONE
RESET ROLE
This command sets the current user
identifier of the current SQL session to be role_name
. 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 current session user must have the SET
option for the
specified role_name
, either
directly or indirectly via a chain of memberships with the
SET
option.
(If the session user is a superuser, any role can be selected.)
The SESSION
and LOCAL
modifiers act the same
as for the regular SET
command.
SET ROLE NONE
sets the current user identifier to the
current session user identifier, as returned by
session_user
. RESET ROLE
sets the
current user identifier to the connection-time setting specified by the
command-line options,
ALTER ROLE
, or
ALTER DATABASE
,
if any such settings exist. Otherwise, RESET ROLE
sets
the current user identifier to the current session user identifier. These
forms can be executed by any user.
Using this command, it is possible to either add privileges or restrict
one's privileges. If the session user role has been granted memberships
WITH INHERIT TRUE
, it automatically has all the
privileges of every such role. In this case, SET ROLE
effectively drops all the privileges except for those which the target role
directly possesses or inherits. On the other hand, if the session user role
has been granted memberships WITH INHERIT FALSE
, the
privileges of the granted roles can't be accessed by default. However, if
the role was granted WITH SET TRUE
, the
session user can use SET ROLE
to drop the privileges
assigned directly to the session user and instead acquire the privileges
available to the named role. If the role was granted WITH INHERIT
FALSE, SET FALSE
then the privileges of that role cannot be
exercised either with or without SET ROLE
.
Note that when a superuser chooses to SET ROLE
to a
non-superuser role, they lose their superuser privileges.
SET ROLE
has effects comparable to
SET SESSION AUTHORIZATION
, 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
.
SET ROLE
does not process session variables as specified by
the role's ALTER ROLE
settings; this only happens during
login.
SET ROLE
cannot be used within a
SECURITY DEFINER
function.
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
PostgreSQL
allows identifier syntax ("
), 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 rolename
"SESSION
and LOCAL
modifiers are a
PostgreSQL extension, as is the
RESET
syntax.