<?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>52.85. pg_settings</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="view-pg-sequences.html" title="52.84. pg_sequences" /><link rel="next" href="view-pg-shadow.html" title="52.86. pg_shadow" /></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">52.85. <code xmlns="http://www.w3.org/1999/xhtml" class="structname">pg_settings</code></th></tr><tr><td width="10%" align="left"><a accesskey="p" href="view-pg-sequences.html" title="52.84. pg_sequences">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="catalogs.html" title="Chapter 52. System Catalogs">Up</a></td><th width="60%" align="center">Chapter 52. System Catalogs</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="view-pg-shadow.html" title="52.86. pg_shadow">Next</a></td></tr></table><hr></hr></div><div class="sect1" id="VIEW-PG-SETTINGS"><div class="titlepage"><div><div><h2 class="title" style="clear: both">52.85. <code class="structname">pg_settings</code></h2></div></div></div><a id="id-1.10.4.87.2" class="indexterm"></a><p>
The view <code class="structname">pg_settings</code> provides access to
run-time parameters of the server. It is essentially an alternative
interface to the <a class="xref" href="sql-show.html" title="SHOW"><span class="refentrytitle">SHOW</span></a>
and <a class="xref" href="sql-set.html" title="SET"><span class="refentrytitle">SET</span></a> commands.
It also provides access to some facts about each parameter that are
not directly available from <code class="command">SHOW</code>, such as minimum and
maximum values.
</p><div class="table" id="id-1.10.4.87.4"><p class="title"><strong>Table 52.86. <code class="structname">pg_settings</code> Columns</strong></p><div class="table-contents"><table class="table" summary="pg_settings Columns" border="1"><colgroup><col /><col /><col /></colgroup><thead><tr><th>Name</th><th>Type</th><th>Description</th></tr></thead><tbody><tr><td><code class="structfield">name</code></td><td><code class="type">text</code></td><td>Run-time configuration parameter name</td></tr><tr><td><code class="structfield">setting</code></td><td><code class="type">text</code></td><td>Current value of the parameter</td></tr><tr><td><code class="structfield">unit</code></td><td><code class="type">text</code></td><td>Implicit unit of the parameter</td></tr><tr><td><code class="structfield">category</code></td><td><code class="type">text</code></td><td>Logical group of the parameter</td></tr><tr><td><code class="structfield">short_desc</code></td><td><code class="type">text</code></td><td>A brief description of the parameter</td></tr><tr><td><code class="structfield">extra_desc</code></td><td><code class="type">text</code></td><td>Additional, more detailed, description of the parameter</td></tr><tr><td><code class="structfield">context</code></td><td><code class="type">text</code></td><td>Context required to set the parameter's value (see below)</td></tr><tr><td><code class="structfield">vartype</code></td><td><code class="type">text</code></td><td>Parameter type (<code class="literal">bool</code>, <code class="literal">enum</code>,
<code class="literal">integer</code>, <code class="literal">real</code>, or <code class="literal">string</code>)
</td></tr><tr><td><code class="structfield">source</code></td><td><code class="type">text</code></td><td>Source of the current parameter value</td></tr><tr><td><code class="structfield">min_val</code></td><td><code class="type">text</code></td><td>Minimum allowed value of the parameter (null for non-numeric
values)</td></tr><tr><td><code class="structfield">max_val</code></td><td><code class="type">text</code></td><td>Maximum allowed value of the parameter (null for non-numeric
values)</td></tr><tr><td><code class="structfield">enumvals</code></td><td><code class="type">text[]</code></td><td>Allowed values of an enum parameter (null for non-enum
values)</td></tr><tr><td><code class="structfield">boot_val</code></td><td><code class="type">text</code></td><td>Parameter value assumed at server startup if the parameter is
not otherwise set</td></tr><tr><td><code class="structfield">reset_val</code></td><td><code class="type">text</code></td><td>Value that <code class="command">RESET</code> would reset the parameter to
in the current session</td></tr><tr><td><code class="structfield">sourcefile</code></td><td><code class="type">text</code></td><td>Configuration file the current value was set in (null for
values set from sources other than configuration files, or when
examined by a user who is neither a superuser or a member of
<code class="literal">pg_read_all_settings</code>); helpful when using
<code class="literal">include</code> directives in configuration files</td></tr><tr><td><code class="structfield">sourceline</code></td><td><code class="type">integer</code></td><td>Line number within the configuration file the current value was
set at (null for values set from sources other than configuration files,
or when examined by a user who is neither a superuser or a member of
<code class="literal">pg_read_all_settings</code>).
</td></tr><tr><td><code class="structfield">pending_restart</code></td><td><code class="type">boolean</code></td><td><code class="literal">true</code> if the value has been changed in the
configuration file but needs a restart; or <code class="literal">false</code>
otherwise.
</td></tr></tbody></table></div></div><br class="table-break" /><p>
There are several possible values of <code class="structfield">context</code>.
In order of decreasing difficulty of changing the setting, they are:
</p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="literal">internal</code></span></dt><dd><p>
These settings cannot be changed directly; they reflect internally
determined values. Some of them may be adjustable by rebuilding the
server with different configuration options, or by changing options
supplied to <code class="command">initdb</code>.
</p></dd><dt><span class="term"><code class="literal">postmaster</code></span></dt><dd><p>
These settings can only be applied when the server starts, so any change
requires restarting the server. Values for these settings are typically
stored in the <code class="filename">postgresql.conf</code> file, or passed on
the command line when starting the server. Of course, settings with any
of the lower <code class="structfield">context</code> types can also be
set at server start time.
</p></dd><dt><span class="term"><code class="literal">sighup</code></span></dt><dd><p>
Changes to these settings can be made in
<code class="filename">postgresql.conf</code> without restarting the server.
Send a <span class="systemitem">SIGHUP</span> signal to the postmaster to
cause it to re-read <code class="filename">postgresql.conf</code> and apply
the changes. The postmaster will also forward the
<span class="systemitem">SIGHUP</span> signal to its child processes so that
they all pick up the new value.
</p></dd><dt><span class="term"><code class="literal">superuser-backend</code></span></dt><dd><p>
Changes to these settings can be made in
<code class="filename">postgresql.conf</code> without restarting the server.
They can also be set for a particular session in the connection request
packet (for example, via <span class="application">libpq</span>'s <code class="literal">PGOPTIONS</code>
environment variable), but only if the connecting user is a superuser.
However, these settings never change in a session after it is started.
If you change them in <code class="filename">postgresql.conf</code>, send a
<span class="systemitem">SIGHUP</span> signal to the postmaster to cause it to
re-read <code class="filename">postgresql.conf</code>. The new values will only
affect subsequently-launched sessions.
</p></dd><dt><span class="term"><code class="literal">backend</code></span></dt><dd><p>
Changes to these settings can be made in
<code class="filename">postgresql.conf</code> without restarting the server.
They can also be set for a particular session in the connection request
packet (for example, via <span class="application">libpq</span>'s <code class="literal">PGOPTIONS</code>
environment variable); any user can make such a change for their session.
However, these settings never change in a session after it is started.
If you change them in <code class="filename">postgresql.conf</code>, send a
<span class="systemitem">SIGHUP</span> signal to the postmaster to cause it to
re-read <code class="filename">postgresql.conf</code>. The new values will only
affect subsequently-launched sessions.
</p></dd><dt><span class="term"><code class="literal">superuser</code></span></dt><dd><p>
These settings can be set from <code class="filename">postgresql.conf</code>,
or within a session via the <code class="command">SET</code> command; but only superusers
can change them via <code class="command">SET</code>. Changes in
<code class="filename">postgresql.conf</code> will affect existing sessions
only if no session-local value has been established with <code class="command">SET</code>.
</p></dd><dt><span class="term"><code class="literal">user</code></span></dt><dd><p>
These settings can be set from <code class="filename">postgresql.conf</code>,
or within a session via the <code class="command">SET</code> command. Any user is
allowed to change their session-local value. Changes in
<code class="filename">postgresql.conf</code> will affect existing sessions
only if no session-local value has been established with <code class="command">SET</code>.
</p></dd></dl></div><p>
See <a class="xref" href="config-setting.html" title="19.1. Setting Parameters">Section 19.1</a> for more information about the various
ways to change these parameters.
</p><p>
The <code class="structname">pg_settings</code> view cannot be inserted into or
deleted from, but it can be updated. An <code class="command">UPDATE</code> applied
to a row of <code class="structname">pg_settings</code> is equivalent to executing
the <a class="xref" href="sql-set.html" title="SET"><span class="refentrytitle">SET</span></a> command on that named
parameter. The change only affects the value used by the current
session. If an <code class="command">UPDATE</code> is issued within a transaction
that is later aborted, the effects of the <code class="command">UPDATE</code> command
disappear when the transaction is rolled back. Once the surrounding
transaction is committed, the effects will persist until the end of the
session, unless overridden by another <code class="command">UPDATE</code> or
<code class="command">SET</code>.
</p></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="view-pg-sequences.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="catalogs.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="view-pg-shadow.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">52.84. <code class="structname">pg_sequences</code> </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> 52.86. <code class="structname">pg_shadow</code></td></tr></table></div></body></html>
