postgresql/doc/src/sgml/ref/reset.sgml

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<!--
doc/src/sgml/ref/reset.sgml
PostgreSQL documentation
-->
<refentry id="sql-reset">
<indexterm zone="sql-reset">
<primary>RESET</primary>
</indexterm>
<refmeta>
<refentrytitle>RESET</refentrytitle>
<manvolnum>7</manvolnum>
<refmiscinfo>SQL - Language Statements</refmiscinfo>
</refmeta>
<refnamediv>
<refname>RESET</refname>
<refpurpose>restore the value of a run-time parameter to the default value</refpurpose>
</refnamediv>
<refsynopsisdiv>
<synopsis>
RESET <replaceable class="parameter">configuration_parameter</replaceable>
RESET ALL
</synopsis>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para>
<command>RESET</command> restores run-time parameters to their
default values. <command>RESET</command> is an alternative
spelling for
<synopsis>
SET <replaceable class="parameter">configuration_parameter</replaceable> TO DEFAULT
</synopsis>
Refer to <xref linkend="sql-set"/> for
details.
</para>
<para>
The default value is defined as the value that the parameter would
have had, if no <command>SET</command> had ever been issued for it in the
current session. The actual source of this value might be a
compiled-in default, the configuration file, command-line options,
or per-database or per-user default settings. This is subtly different
from defining it as <quote>the value that the parameter had at session
start</quote>, because if the value came from the configuration file, it
will be reset to whatever is specified by the configuration file now.
See <xref linkend="runtime-config"/> for details.
</para>
<para>
The transactional behavior of <command>RESET</command> is the same as
<command>SET</command>: its effects will be undone by transaction rollback.
</para>
</refsect1>
<refsect1>
<title>Parameters</title>
<variablelist>
<varlistentry>
<term><replaceable class="parameter">configuration_parameter</replaceable></term>
<listitem>
<para>
Name of a settable run-time parameter. Available parameters are
documented in <xref linkend="runtime-config"/> and on the
<xref linkend="sql-set"/> reference page.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>ALL</literal></term>
<listitem>
<para>
Resets all settable run-time parameters to default values.
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Examples</title>
<para>
Set the <varname>timezone</varname> configuration variable to its default value:
<screen>
RESET timezone;
</screen></para>
</refsect1>
<refsect1>
<title>Compatibility</title>
<para>
<command>RESET</command> is a <productname>PostgreSQL</productname> extension.
</para>
</refsect1>
<refsect1>
<title>See Also</title>
<simplelist type="inline">
<member><xref linkend="sql-set"/></member>
<member><xref linkend="sql-show"/></member>
</simplelist>
</refsect1>
</refentry>