<?xml version="1.0" encoding="UTF-8" standalone="no"?> <!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><div xmlns="http://www.w3.org/TR/xhtml1/transitional" 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 11.5 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></hr></div><div class="refentry" id="SQL-SET-SESSION-AUTHORIZATION"><div class="titlepage"></div><a id="id-1.9.3.176.1" 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-1.9.3.176.5"><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="xref" href="sql-set-role.html" title="SET ROLE"><span class="refentrytitle">SET ROLE</span></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="xref" href="sql-set.html" title="SET"><span class="refentrytitle">SET</span></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-1.9.3.176.6"><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-1.9.3.176.7"><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-1.9.3.176.8"><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-1.9.3.176.9"><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">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="sql-commands.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="sql-set-transaction.html">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">Home</a></td><td width="40%" align="right" valign="top"> SET TRANSACTION</td></tr></table></div></body></html>
