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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <HTML ><HEAD ><TITLE >pg_settings</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK REV="MADE" HREF="mailto:pgsql-docs@postgresql.org"><LINK REL="HOME" TITLE="PostgreSQL 9.2.24 Documentation" HREF="index.html"><LINK REL="UP" TITLE="System Catalogs" HREF="catalogs.html"><LINK REL="PREVIOUS" TITLE="pg_seclabels" HREF="view-pg-seclabels.html"><LINK REL="NEXT" TITLE="pg_shadow" HREF="view-pg-shadow.html"><LINK REL="STYLESHEET" TYPE="text/css" HREF="stylesheet.css"><META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=ISO-8859-1"><META NAME="creation" CONTENT="2017-11-06T22:43:11"></HEAD ><BODY CLASS="SECT1" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="5" ALIGN="center" VALIGN="bottom" ><A HREF="index.html" >PostgreSQL 9.2.24 Documentation</A ></TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="top" ><A TITLE="pg_seclabels" HREF="view-pg-seclabels.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="10%" ALIGN="left" VALIGN="top" ><A HREF="catalogs.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="60%" ALIGN="center" VALIGN="bottom" >Chapter 45. System Catalogs</TD ><TD WIDTH="20%" ALIGN="right" VALIGN="top" ><A TITLE="pg_shadow" HREF="view-pg-shadow.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="SECT1" ><H1 CLASS="SECT1" ><A NAME="VIEW-PG-SETTINGS" >45.64. <TT CLASS="STRUCTNAME" >pg_settings</TT ></A ></H1 ><P > The view <TT CLASS="STRUCTNAME" >pg_settings</TT > provides access to run-time parameters of the server. It is essentially an alternative interface to the <A HREF="sql-show.html" >SHOW</A > and <A HREF="sql-set.html" >SET</A > commands. It also provides access to some facts about each parameter that are not directly available from <TT CLASS="COMMAND" >SHOW</TT >, such as minimum and maximum values. </P ><DIV CLASS="TABLE" ><A NAME="AEN94907" ></A ><P ><B >Table 45-65. <TT CLASS="STRUCTNAME" >pg_settings</TT > Columns</B ></P ><TABLE BORDER="1" CLASS="CALSTABLE" ><COL><COL><COL><THEAD ><TR ><TH >Name</TH ><TH >Type</TH ><TH >Description</TH ></TR ></THEAD ><TBODY ><TR ><TD ><TT CLASS="STRUCTFIELD" >name</TT ></TD ><TD ><TT CLASS="TYPE" >text</TT ></TD ><TD >Run-time configuration parameter name</TD ></TR ><TR ><TD ><TT CLASS="STRUCTFIELD" >setting</TT ></TD ><TD ><TT CLASS="TYPE" >text</TT ></TD ><TD >Current value of the parameter</TD ></TR ><TR ><TD ><TT CLASS="STRUCTFIELD" >unit</TT ></TD ><TD ><TT CLASS="TYPE" >text</TT ></TD ><TD >Implicit unit of the parameter</TD ></TR ><TR ><TD ><TT CLASS="STRUCTFIELD" >category</TT ></TD ><TD ><TT CLASS="TYPE" >text</TT ></TD ><TD >Logical group of the parameter</TD ></TR ><TR ><TD ><TT CLASS="STRUCTFIELD" >short_desc</TT ></TD ><TD ><TT CLASS="TYPE" >text</TT ></TD ><TD >A brief description of the parameter</TD ></TR ><TR ><TD ><TT CLASS="STRUCTFIELD" >extra_desc</TT ></TD ><TD ><TT CLASS="TYPE" >text</TT ></TD ><TD >Additional, more detailed, description of the parameter</TD ></TR ><TR ><TD ><TT CLASS="STRUCTFIELD" >context</TT ></TD ><TD ><TT CLASS="TYPE" >text</TT ></TD ><TD >Context required to set the parameter's value (see below)</TD ></TR ><TR ><TD ><TT CLASS="STRUCTFIELD" >vartype</TT ></TD ><TD ><TT CLASS="TYPE" >text</TT ></TD ><TD >Parameter type (<TT CLASS="LITERAL" >bool</TT >, <TT CLASS="LITERAL" >enum</TT >, <TT CLASS="LITERAL" >integer</TT >, <TT CLASS="LITERAL" >real</TT >, or <TT CLASS="LITERAL" >string</TT >) </TD ></TR ><TR ><TD ><TT CLASS="STRUCTFIELD" >source</TT ></TD ><TD ><TT CLASS="TYPE" >text</TT ></TD ><TD >Source of the current parameter value</TD ></TR ><TR ><TD ><TT CLASS="STRUCTFIELD" >min_val</TT ></TD ><TD ><TT CLASS="TYPE" >text</TT ></TD ><TD >Minimum allowed value of the parameter (null for non-numeric values)</TD ></TR ><TR ><TD ><TT CLASS="STRUCTFIELD" >max_val</TT ></TD ><TD ><TT CLASS="TYPE" >text</TT ></TD ><TD >Maximum allowed value of the parameter (null for non-numeric values)</TD ></TR ><TR ><TD ><TT CLASS="STRUCTFIELD" >enumvals</TT ></TD ><TD ><TT CLASS="TYPE" >text[]</TT ></TD ><TD >Allowed values of an enum parameter (null for non-enum values)</TD ></TR ><TR ><TD ><TT CLASS="STRUCTFIELD" >boot_val</TT ></TD ><TD ><TT CLASS="TYPE" >text</TT ></TD ><TD >Parameter value assumed at server startup if the parameter is not otherwise set</TD ></TR ><TR ><TD ><TT CLASS="STRUCTFIELD" >reset_val</TT ></TD ><TD ><TT CLASS="TYPE" >text</TT ></TD ><TD >Value that <TT CLASS="COMMAND" >RESET</TT > would reset the parameter to in the current session</TD ></TR ><TR ><TD ><TT CLASS="STRUCTFIELD" >sourcefile</TT ></TD ><TD ><TT CLASS="TYPE" >text</TT ></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 non-superuser); helpful when using <TT CLASS="LITERAL" >include</TT > directives in configuration files</TD ></TR ><TR ><TD ><TT CLASS="STRUCTFIELD" >sourceline</TT ></TD ><TD ><TT CLASS="TYPE" >integer</TT ></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 non-superuser) </TD ></TR ></TBODY ></TABLE ></DIV ><P > There are several possible values of <TT CLASS="STRUCTFIELD" >context</TT >. In order of decreasing difficulty of changing the setting, they are: </P ><P ></P ><DIV CLASS="VARIABLELIST" ><DL ><DT ><TT CLASS="LITERAL" >internal</TT ></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 <TT CLASS="COMMAND" >initdb</TT >. </P ></DD ><DT ><TT CLASS="LITERAL" >postmaster</TT ></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 <TT CLASS="FILENAME" >postgresql.conf</TT > file, or passed on the command line when starting the server. Of course, settings with any of the lower <TT CLASS="STRUCTFIELD" >context</TT > types can also be set at server start time. </P ></DD ><DT ><TT CLASS="LITERAL" >sighup</TT ></DT ><DD ><P > Changes to these settings can be made in <TT CLASS="FILENAME" >postgresql.conf</TT > without restarting the server. Send a <SPAN CLASS="SYSTEMITEM" >SIGHUP</SPAN > signal to the postmaster to cause it to re-read <TT CLASS="FILENAME" >postgresql.conf</TT > 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 ><TT CLASS="LITERAL" >backend</TT ></DT ><DD ><P > Changes to these settings can be made in <TT CLASS="FILENAME" >postgresql.conf</TT > 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 <TT CLASS="LITERAL" >PGOPTIONS</TT > environment variable). However, these settings never change in a session after it is started. If you change them in <TT CLASS="FILENAME" >postgresql.conf</TT >, send a <SPAN CLASS="SYSTEMITEM" >SIGHUP</SPAN > signal to the postmaster to cause it to re-read <TT CLASS="FILENAME" >postgresql.conf</TT >. The new values will only affect subsequently-launched sessions. </P ></DD ><DT ><TT CLASS="LITERAL" >superuser</TT ></DT ><DD ><P > These settings can be set from <TT CLASS="FILENAME" >postgresql.conf</TT >, or within a session via the <TT CLASS="COMMAND" >SET</TT > command; but only superusers can change them via <TT CLASS="COMMAND" >SET</TT >. Changes in <TT CLASS="FILENAME" >postgresql.conf</TT > will affect existing sessions only if no session-local value has been established with <TT CLASS="COMMAND" >SET</TT >. </P ></DD ><DT ><TT CLASS="LITERAL" >user</TT ></DT ><DD ><P > These settings can be set from <TT CLASS="FILENAME" >postgresql.conf</TT >, or within a session via the <TT CLASS="COMMAND" >SET</TT > command. Any user is allowed to change his session-local value. Changes in <TT CLASS="FILENAME" >postgresql.conf</TT > will affect existing sessions only if no session-local value has been established with <TT CLASS="COMMAND" >SET</TT >. </P ></DD ></DL ></DIV ><P > See <A HREF="config-setting.html" >Section 18.1</A > for more information about the various ways to change these parameters. </P ><P > The <TT CLASS="STRUCTNAME" >pg_settings</TT > view cannot be inserted into or deleted from, but it can be updated. An <TT CLASS="COMMAND" >UPDATE</TT > applied to a row of <TT CLASS="STRUCTNAME" >pg_settings</TT > is equivalent to executing the <A HREF="sql-set.html" >SET</A > command on that named parameter. The change only affects the value used by the current session. If an <TT CLASS="COMMAND" >UPDATE</TT > is issued within a transaction that is later aborted, the effects of the <TT CLASS="COMMAND" >UPDATE</TT > 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 <TT CLASS="COMMAND" >UPDATE</TT > or <TT CLASS="COMMAND" >SET</TT >. </P ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="view-pg-seclabels.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="view-pg-shadow.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><TT CLASS="STRUCTNAME" >pg_seclabels</TT ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="catalogs.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><TT CLASS="STRUCTNAME" >pg_shadow</TT ></TD ></TR ></TABLE ></DIV ></BODY ></HTML >