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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 V1.79.1" /><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 12.4 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>
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