Provided by: postgresql-client-8.3_8.3.8-1_i386 bug

NAME

       SET ROLE - set the current user identifier of the current session

SYNOPSIS

       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 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 SET
       [set(7)] 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   SET   SESSION   AUTHORIZATION
       [set_session_authorization(7)],  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 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)]