SET ROLE
SET ROLE — set the current user identifier of the current session
Synopsis
SET [ SESSION | LOCAL ] ROLE role_name
SET [ SESSION | LOCAL ] ROLE NONE
RESET ROLE
Description
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 specified role_name
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 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.
Notes
Using this command, it is possible to either add privileges or restrict one's privileges. If the session user role has the INHERIT
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 NOINHERIT
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, 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.
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
Postgres Pro 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; Postgres Pro does not make this restriction because there is no reason to. The rolename
"SESSION
and LOCAL
modifiers are a Postgres Pro extension, as is the RESET
syntax.