NAME

       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 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.

NOTES

       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.

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

       SET SESSION AUTHORIZATION (SET_SESSION_AUTHORIZATION(7))