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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>SET SESSION AUTHORIZATION</title><link rel="stylesheet" type="text/css" href="stylesheet.css" /><link rev="made" href="pgsql-docs@lists.postgresql.org" /><meta name="generator" content="DocBook XSL Stylesheets Vsnapshot" /><link rel="prev" href="sql-set-role.html" title="SET ROLE" /><link rel="next" href="sql-set-transaction.html" title="SET TRANSACTION" /></head><body id="docContent" class="container-fluid col-10"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">SET SESSION AUTHORIZATION</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="sql-set-role.html" title="SET ROLE">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="sql-commands.html" title="SQL Commands">Up</a></td><th width="60%" align="center">SQL Commands</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 16.3 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="sql-set-transaction.html" title="SET TRANSACTION">Next</a></td></tr></table><hr /></div><div class="refentry" id="SQL-SET-SESSION-AUTHORIZATION"><div class="titlepage"></div><a id="id-1.9.3.177.1" class="indexterm"></a><div class="refnamediv"><h2><span class="refentrytitle">SET SESSION AUTHORIZATION</span></h2><p>SET SESSION AUTHORIZATION — set the session user identifier and the current user identifier of the current session</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><pre class="synopsis">
SET [ SESSION | LOCAL ] SESSION AUTHORIZATION <em class="replaceable"><code>user_name</code></em>
SET [ SESSION | LOCAL ] SESSION AUTHORIZATION DEFAULT
RESET SESSION AUTHORIZATION
</pre></div><div class="refsect1" id="id-1.9.3.177.5"><h2>Description</h2><p>
This command sets the session user identifier and the current user
identifier of the current SQL session to be <em class="replaceable"><code>user_name</code></em>. The user name can 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.
</p><p>
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
might change temporarily in the context of <code class="literal">SECURITY DEFINER</code>
functions and similar mechanisms; it can also be changed by
<a class="link" href="sql-set-role.html" title="SET ROLE"><code class="command">SET ROLE</code></a>.
The current user identifier is relevant for permission checking.
</p><p>
The session user identifier can be changed only if the initial session
user (the <em class="firstterm">authenticated user</em>) had the
superuser privilege. Otherwise, the command is accepted only if it
specifies the authenticated user name.
</p><p>
The <code class="literal">SESSION</code> and <code class="literal">LOCAL</code> modifiers act the same
as for the regular <a class="link" href="sql-set.html" title="SET"><code class="command">SET</code></a>
command.
</p><p>
The <code class="literal">DEFAULT</code> and <code class="literal">RESET</code> forms reset the session
and current user identifiers to be the originally authenticated user
name. These forms can be executed by any user.
</p></div><div class="refsect1" id="id-1.9.3.177.6"><h2>Notes</h2><p>
<code class="command">SET SESSION AUTHORIZATION</code> cannot be used within a
<code class="literal">SECURITY DEFINER</code> function.
</p></div><div class="refsect1" id="id-1.9.3.177.7"><h2>Examples</h2><pre class="programlisting">
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
</pre></div><div class="refsect1" id="id-1.9.3.177.8"><h2>Compatibility</h2><p>
The SQL standard allows some other expressions to appear in place
of the literal <em class="replaceable"><code>user_name</code></em>, but these options
are not important in practice. <span class="productname">PostgreSQL</span>
allows identifier syntax (<code class="literal">"<em class="replaceable"><code>username</code></em>"</code>), which SQL
does not. SQL does not allow this command during a transaction;
<span class="productname">PostgreSQL</span> does not make this
restriction because there is no reason to.
The <code class="literal">SESSION</code> and <code class="literal">LOCAL</code> modifiers are a
<span class="productname">PostgreSQL</span> extension, as is the
<code class="literal">RESET</code> syntax.
</p><p>
The privileges necessary to execute this command are left
implementation-defined by the standard.
</p></div><div class="refsect1" id="id-1.9.3.177.9"><h2>See Also</h2><span class="simplelist"><a class="xref" href="sql-set-role.html" title="SET ROLE"><span class="refentrytitle">SET ROLE</span></a></span></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="sql-set-role.html" title="SET ROLE">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="sql-commands.html" title="SQL Commands">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="sql-set-transaction.html" title="SET TRANSACTION">Next</a></td></tr><tr><td width="40%" align="left" valign="top">SET ROLE </td><td width="20%" align="center"><a accesskey="h" href="index.html" title="PostgreSQL 16.3 Documentation">Home</a></td><td width="40%" align="right" valign="top"> SET TRANSACTION</td></tr></table></div></body></html>