Index for Section SESSION

Alphabetical listing for S

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SET
NAME
  SET SESSION AUTHORIZATION - set the session user identifier and the current
  user identifier of the current session

SYNOPSIS
  SET [ SESSION | LOCAL ] SESSION AUTHORIZATION username
  SET [ SESSION | LOCAL ] SESSION AUTHORIZATION DEFAULT
  RESET SESSION AUTHORIZATION

DESCRIPTION
  This command sets the session user identifier and the current user
  identifier of the current SQL-session context to be username. The user 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 become a superuser.

  The session user identifier is initially set to be the (possibly
  authenticated) user name provided by the client. The current user
  identifier is normally equal to the session user identifier, but may change
  temporarily in the context of ``setuid'' functions and similar mechanisms.
  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 SESSION and LOCAL modifiers act the same as for the regular SET
  [set(5)] command.

  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.

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 username which are not important in practice. PostgreSQL allows
  identifier syntax ("username"), which SQL does not. SQL does not allow this
  command during a transaction; PostgreSQL does not make this restriction
  because there is no reason to. The privileges necessary to execute this
  command are left implementation-defined by the standard.

Index for Section SESSION

Alphabetical listing for S

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