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Green_GoodERP18_FSJ_Standard/PostgreSQL/doc/postgresql/html/view-pg-settings.html

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  1. <?xml version="1.0" encoding="UTF-8" standalone="no"?>

  2. <!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>51.86. 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 V1.79.1" /><link rel="prev" href="view-pg-sequences.html" title="51.85. pg_sequences" /><link rel="next" href="view-pg-shadow.html" title="51.87. 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">51.86. <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="51.85. pg_sequences">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="catalogs.html" title="Chapter 51. System Catalogs">Up</a></td><th width="60%" align="center">Chapter 51. System Catalogs</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="view-pg-shadow.html" title="51.87. 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">51.86. <code class="structname">pg_settings</code></h2></div></div></div><a id="id-1.10.4.88.2" class="indexterm"></a><p>

  3.    The view <code class="structname">pg_settings</code> provides access to

  4.    run-time parameters of the server.  It is essentially an alternative

  5.    interface to the <a class="xref" href="sql-show.html" title="SHOW"><span class="refentrytitle">SHOW</span></a>

  6.    and <a class="xref" href="sql-set.html" title="SET"><span class="refentrytitle">SET</span></a> commands.

  7.    It also provides access to some facts about each parameter that are

  8.    not directly available from <code class="command">SHOW</code>, such as minimum and

  9.    maximum values.

  10.   </p><div class="table" id="id-1.10.4.88.4"><p class="title"><strong>Table 51.87. <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>,

  11.        <code class="literal">integer</code>, <code class="literal">real</code>, or <code class="literal">string</code>)

  12.       </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

  13.       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

  14.       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

  15.       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

  16.       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

  17.       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

  18.       values set from sources other than configuration files, or when

  19.       examined by a user who is neither a superuser or a member of

  20.       <code class="literal">pg_read_all_settings</code>); helpful when using

  21.       <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

  22.       set at (null for values set from sources other than configuration files,

  23.       or when examined by a user who is neither a superuser or a member of

  24.       <code class="literal">pg_read_all_settings</code>).

  25.       </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

  26.       configuration file but needs a restart; or <code class="literal">false</code>

  27.       otherwise.

  28.       </td></tr></tbody></table></div></div><br class="table-break" /><p>

  29.    There are several possible values of <code class="structfield">context</code>.

  30.    In order of decreasing difficulty of changing the setting, they are:

  31.   </p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="literal">internal</code></span></dt><dd><p>

  32.       These settings cannot be changed directly; they reflect internally

  33.       determined values.  Some of them may be adjustable by rebuilding the

  34.       server with different configuration options, or by changing options

  35.       supplied to <code class="command">initdb</code>.

  36.      </p></dd><dt><span class="term"><code class="literal">postmaster</code></span></dt><dd><p>

  37.       These settings can only be applied when the server starts, so any change

  38.       requires restarting the server.  Values for these settings are typically

  39.       stored in the <code class="filename">postgresql.conf</code> file, or passed on

  40.       the command line when starting the server.  Of course, settings with any

  41.       of the lower <code class="structfield">context</code> types can also be

  42.       set at server start time.

  43.      </p></dd><dt><span class="term"><code class="literal">sighup</code></span></dt><dd><p>

  44.       Changes to these settings can be made in

  45.       <code class="filename">postgresql.conf</code> without restarting the server.

  46.       Send a <span class="systemitem">SIGHUP</span> signal to the postmaster to

  47.       cause it to re-read <code class="filename">postgresql.conf</code> and apply

  48.       the changes.  The postmaster will also forward the

  49.       <span class="systemitem">SIGHUP</span> signal to its child processes so that

  50.       they all pick up the new value.

  51.      </p></dd><dt><span class="term"><code class="literal">superuser-backend</code></span></dt><dd><p>

  52.       Changes to these settings can be made in

  53.       <code class="filename">postgresql.conf</code> without restarting the server.

  54.       They can also be set for a particular session in the connection request

  55.       packet (for example, via <span class="application">libpq</span>'s <code class="literal">PGOPTIONS</code>

  56.       environment variable), but only if the connecting user is a superuser.

  57.       However, these settings never change in a session after it is started.

  58.       If you change them in <code class="filename">postgresql.conf</code>, send a

  59.       <span class="systemitem">SIGHUP</span> signal to the postmaster to cause it to

  60.       re-read <code class="filename">postgresql.conf</code>.  The new values will only

  61.       affect subsequently-launched sessions.

  62.      </p></dd><dt><span class="term"><code class="literal">backend</code></span></dt><dd><p>

  63.       Changes to these settings can be made in

  64.       <code class="filename">postgresql.conf</code> without restarting the server.

  65.       They can also be set for a particular session in the connection request

  66.       packet (for example, via <span class="application">libpq</span>'s <code class="literal">PGOPTIONS</code>

  67.       environment variable); any user can make such a change for their session.

  68.       However, these settings never change in a session after it is started.

  69.       If you change them in <code class="filename">postgresql.conf</code>, send a

  70.       <span class="systemitem">SIGHUP</span> signal to the postmaster to cause it to

  71.       re-read <code class="filename">postgresql.conf</code>.  The new values will only

  72.       affect subsequently-launched sessions.

  73.      </p></dd><dt><span class="term"><code class="literal">superuser</code></span></dt><dd><p>

  74.       These settings can be set from <code class="filename">postgresql.conf</code>,

  75.       or within a session via the <code class="command">SET</code> command; but only superusers

  76.       can change them via <code class="command">SET</code>.  Changes in

  77.       <code class="filename">postgresql.conf</code> will affect existing sessions

  78.       only if no session-local value has been established with <code class="command">SET</code>.

  79.      </p></dd><dt><span class="term"><code class="literal">user</code></span></dt><dd><p>

  80.       These settings can be set from <code class="filename">postgresql.conf</code>,

  81.       or within a session via the <code class="command">SET</code> command.  Any user is

  82.       allowed to change their session-local value.  Changes in

  83.       <code class="filename">postgresql.conf</code> will affect existing sessions

  84.       only if no session-local value has been established with <code class="command">SET</code>.

  85.      </p></dd></dl></div><p>

  86.    See <a class="xref" href="config-setting.html" title="19.1. Setting Parameters">Section 19.1</a> for more information about the various

  87.    ways to change these parameters.

  88.   </p><p>

  89.    The <code class="structname">pg_settings</code> view cannot be inserted into or

  90.    deleted from, but it can be updated.  An <code class="command">UPDATE</code> applied

  91.    to a row of <code class="structname">pg_settings</code> is equivalent to executing

  92.    the <a class="xref" href="sql-set.html" title="SET"><span class="refentrytitle">SET</span></a> command on that named

  93.    parameter. The change only affects the value used by the current

  94.    session. If an <code class="command">UPDATE</code> is issued within a transaction

  95.    that is later aborted, the effects of the <code class="command">UPDATE</code> command

  96.    disappear when the transaction is rolled back. Once the surrounding

  97.    transaction is committed, the effects will persist until the end of the

  98.    session, unless overridden by another <code class="command">UPDATE</code> or

  99.    <code class="command">SET</code>.

  100.   </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">51.85. <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"> 51.87. <code class="structname">pg_shadow</code></td></tr></table></div></body></html>
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