SET SESSION AUTHORIZATION
Sets the session role identifier and the current role identifier of the current session.
Synopsis
SET [SESSION | LOCAL] SESSION AUTHORIZATION <rolename>
SET [SESSION | LOCAL] SESSION AUTHORIZATION DEFAULT
RESET SESSION AUTHORIZATION
Description
This command sets the session role identifier and the current role identifier of the current SQL-session context to <rolename> . The role name may be written as either an identifier or a string literal. Using this command, it is possible, for example, to temporarily become an unprivileged user and later switch back to being a superuser.
The session role identifier is initially set to be the (possibly authenticated) role name provided by the client. The current role identifier is normally equal to the session user identifier, but may change temporarily in the context of setuid functions and similar mechanisms; it can also be changed by SET ROLE. The current user identifier is relevant for permission checking.
The session user identifier may be changed only if the initial session user (the authenticated user) had the superuser privilege. Otherwise, the command is accepted only if it specifies the authenticated user name.
The DEFAULT and RESET forms reset the session and current user identifiers to be the originally authenticated user name. These forms may be executed by any user.
Parameters
COMMIT or ROLLBACK, the session-level setting takes effect again. Note that SET LOCAL will appear to have no effect if it is executed outside of a transaction.RESET
Examples
SELECT SESSION_USER, CURRENT_USER;
session_user | current_user
--------------+--------------
peter | peter
SET SESSION AUTHORIZATION 'paul';
SELECT SESSION_USER, CURRENT_USER;
session_user | current_user
--------------+--------------
paul | paul
Compatibility
The SQL standard allows some other expressions to appear in place of the literal <rolename>, but these options are not important in practice. HAWQ allows identifier syntax (<rolename>), while SQL does not. SQL does not allow this command during a transaction; HAWQ does not make this restriction. The SESSION and LOCAL modifiers are a HAWQ extension, as is the RESET syntax.