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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>DISCARD</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-delete.html" title="DELETE" /><link rel="next" href="sql-do.html" title="DO" /></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">DISCARD</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="sql-delete.html" title="DELETE">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-do.html" title="DO">Next</a></td></tr></table><hr></hr></div><div class="refentry" id="SQL-DISCARD"><div class="titlepage"></div><a id="id-1.9.3.101.1" class="indexterm"></a><div class="refnamediv"><h2><span class="refentrytitle">DISCARD</span></h2><p>DISCARD — discard session state</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><pre class="synopsis">
DISCARD { ALL | PLANS | SEQUENCES | TEMPORARY | TEMP }
</pre></div><div class="refsect1" id="id-1.9.3.101.5"><h2>Description</h2><p>
<code class="command">DISCARD</code> releases internal resources associated with a
database session. This command is useful for partially or fully
resetting the session's state. There are several subcommands to
release different types of resources; the <code class="command">DISCARD ALL</code>
variant subsumes all the others, and also resets additional state.
</p></div><div class="refsect1" id="id-1.9.3.101.6"><h2>Parameters</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="literal">PLANS</code></span></dt><dd><p>
Releases all cached query plans, forcing re-planning to occur
the next time the associated prepared statement is used.
</p></dd><dt><span class="term"><code class="literal">SEQUENCES</code></span></dt><dd><p>
Discards all cached sequence-related state,
including <code class="function">currval()</code>/<code class="function">lastval()</code>
information and any preallocated sequence values that have not
yet been returned by <code class="function">nextval()</code>.
(See <a class="xref" href="sql-createsequence.html" title="CREATE SEQUENCE"><span class="refentrytitle">CREATE SEQUENCE</span></a> for a description of
preallocated sequence values.)
</p></dd><dt><span class="term"><code class="literal">TEMPORARY</code> or <code class="literal">TEMP</code></span></dt><dd><p>
Drops all temporary tables created in the current session.
</p></dd><dt><span class="term"><code class="literal">ALL</code></span></dt><dd><p>
Releases all temporary resources associated with the current
session and resets the session to its initial state.
Currently, this has the same effect as executing the following sequence
of statements:
</p><pre class="programlisting">
SET SESSION AUTHORIZATION DEFAULT;
RESET ALL;
DEALLOCATE ALL;
CLOSE ALL;
UNLISTEN *;
SELECT pg_advisory_unlock_all();
DISCARD PLANS;
DISCARD SEQUENCES;
DISCARD TEMP;
</pre></dd></dl></div></div><div class="refsect1" id="id-1.9.3.101.7"><h2>Notes</h2><p>
<code class="command">DISCARD ALL</code> cannot be executed inside a transaction block.
</p></div><div class="refsect1" id="id-1.9.3.101.8"><h2>Compatibility</h2><p>
<code class="command">DISCARD</code> is a <span class="productname">PostgreSQL</span> extension.
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