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diff --git a/doc/src/sgml/html/sql-altersystem.html b/doc/src/sgml/html/sql-altersystem.html new file mode 100644 index 0000000..b0b072e --- /dev/null +++ b/doc/src/sgml/html/sql-altersystem.html @@ -0,0 +1,65 @@ +<?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>ALTER SYSTEM</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-altersubscription.html" title="ALTER SUBSCRIPTION" /><link rel="next" href="sql-altertable.html" title="ALTER TABLE" /></head><body id="docContent" class="container-fluid col-10"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">ALTER SYSTEM</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="sql-altersubscription.html" title="ALTER SUBSCRIPTION">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 15.5 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="sql-altertable.html" title="ALTER TABLE">Next</a></td></tr></table><hr /></div><div class="refentry" id="SQL-ALTERSYSTEM"><div class="titlepage"></div><a id="id-1.9.3.34.1" class="indexterm"></a><div class="refnamediv"><h2><span class="refentrytitle">ALTER SYSTEM</span></h2><p>ALTER SYSTEM — change a server configuration parameter</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><pre class="synopsis"> +ALTER SYSTEM SET <em class="replaceable"><code>configuration_parameter</code></em> { TO | = } { <em class="replaceable"><code>value</code></em> [, ...] | DEFAULT } + +ALTER SYSTEM RESET <em class="replaceable"><code>configuration_parameter</code></em> +ALTER SYSTEM RESET ALL +</pre></div><div class="refsect1" id="id-1.9.3.34.5"><h2>Description</h2><p> + <code class="command">ALTER SYSTEM</code> is used for changing server configuration + parameters across the entire database cluster. It can be more convenient + than the traditional method of manually editing + the <code class="filename">postgresql.conf</code> file. + <code class="command">ALTER SYSTEM</code> writes the given parameter setting to + the <code class="filename">postgresql.auto.conf</code> file, which is read in + addition to <code class="filename">postgresql.conf</code>. + Setting a parameter to <code class="literal">DEFAULT</code>, or using the + <code class="command">RESET</code> variant, removes that configuration entry from the + <code class="filename">postgresql.auto.conf</code> file. Use <code class="literal">RESET + ALL</code> to remove all such configuration entries. + </p><p> + Values set with <code class="command">ALTER SYSTEM</code> will be effective after + the next server configuration reload, or after the next server restart + in the case of parameters that can only be changed at server start. + A server configuration reload can be commanded by calling the SQL + function <code class="function">pg_reload_conf()</code>, running <code class="literal">pg_ctl reload</code>, + or sending a <span class="systemitem">SIGHUP</span> signal to the main server process. + </p><p> + Only superusers and users granted <code class="literal">ALTER SYSTEM</code> privilege + on a parameter can change it using <code class="command">ALTER SYSTEM</code>. Also, since + this command acts directly on the file system and cannot be rolled back, + it is not allowed inside a transaction block or function. + </p></div><div class="refsect1" id="id-1.9.3.34.6"><h2>Parameters</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="replaceable"><code>configuration_parameter</code></em></span></dt><dd><p> + Name of a settable configuration parameter. Available parameters are + documented in <a class="xref" href="runtime-config.html" title="Chapter 20. Server Configuration">Chapter 20</a>. + </p></dd><dt><span class="term"><em class="replaceable"><code>value</code></em></span></dt><dd><p> + New value of the parameter. Values can be specified as string + constants, identifiers, numbers, or comma-separated lists of + these, as appropriate for the particular parameter. + Values that are neither numbers nor valid identifiers must be quoted. + <code class="literal">DEFAULT</code> can be written to specify removing the + parameter and its value from <code class="filename">postgresql.auto.conf</code>. + </p><p> + For some list-accepting parameters, quoted values will produce + double-quoted output to preserve whitespace and commas; for others, + double-quotes must be used inside single-quoted strings to get + this effect. + </p></dd></dl></div></div><div class="refsect1" id="id-1.9.3.34.7"><h2>Notes</h2><p> + This command can't be used to set <a class="xref" href="runtime-config-file-locations.html#GUC-DATA-DIRECTORY">data_directory</a>, + nor parameters that are not allowed in <code class="filename">postgresql.conf</code> + (e.g., <a class="link" href="runtime-config-preset.html" title="20.15. Preset Options">preset options</a>). + </p><p> + See <a class="xref" href="config-setting.html" title="20.1. Setting Parameters">Section 20.1</a> for other ways to set the parameters. + </p></div><div class="refsect1" id="id-1.9.3.34.8"><h2>Examples</h2><p> + Set the <code class="literal">wal_level</code>: +</p><pre class="programlisting"> +ALTER SYSTEM SET wal_level = replica; +</pre><p> + </p><p> + Undo that, restoring whatever setting was effective + in <code class="filename">postgresql.conf</code>: +</p><pre class="programlisting"> +ALTER SYSTEM RESET wal_level; +</pre></div><div class="refsect1" id="id-1.9.3.34.9"><h2>Compatibility</h2><p> + The <code class="command">ALTER SYSTEM</code> statement is a + <span class="productname">PostgreSQL</span> extension. + </p></div><div class="refsect1" id="id-1.9.3.34.10"><h2>See Also</h2><span class="simplelist"><a class="xref" href="sql-set.html" title="SET"><span class="refentrytitle">SET</span></a>, <a class="xref" href="sql-show.html" title="SHOW"><span class="refentrytitle">SHOW</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-altersubscription.html" title="ALTER SUBSCRIPTION">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-altertable.html" title="ALTER TABLE">Next</a></td></tr><tr><td width="40%" align="left" valign="top">ALTER SUBSCRIPTION </td><td width="20%" align="center"><a accesskey="h" href="index.html" title="PostgreSQL 15.5 Documentation">Home</a></td><td width="40%" align="right" valign="top"> ALTER TABLE</td></tr></table></div></body></html>
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