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doc/src/sgml/ref/pg_controldata.sgml
751ad0f9ff465a265348b85d47d16583a048678928cca8f100000003000009c7
<!--
doc/src/sgml/ref/pg_controldata.sgml
PostgreSQL documentation
-->

<refentry id="app-pgcontroldata">
 <indexterm zone="app-pgcontroldata">
  <primary>pg_controldata</primary>
 </indexterm>

 <refmeta>
  <refentrytitle><application>pg_controldata</application></refentrytitle>
  <manvolnum>1</manvolnum>
  <refmiscinfo>Application</refmiscinfo>
 </refmeta>

 <refnamediv>
  <refname>pg_controldata</refname>
  <refpurpose>display control information of a <productname>PostgreSQL</productname> database cluster</refpurpose>
 </refnamediv>

 <refsynopsisdiv>
  <cmdsynopsis>
   <command>pg_controldata</command>
   <arg choice="opt"><replaceable class="parameter">option</replaceable></arg>
   <group choice="opt">
    <group choice="opt">
     <arg choice="plain"><option>-D</option></arg>
     <arg choice="plain"><option>--pgdata</option></arg>
    </group>
    <replaceable class="parameter">datadir</replaceable>
   </group>
  </cmdsynopsis>
 </refsynopsisdiv>

 <refsect1 id="r1-app-pgcontroldata-1">
  <title>Description</title>
  <para>
   <command>pg_controldata</command> prints information initialized during
   <command>initdb</command>, such as the catalog version.
   It also shows information about write-ahead logging and checkpoint
   processing.  This information is cluster-wide, and not specific to any one
   database.
  </para>

  <para>
   This utility can only be run by the user who initialized the cluster because
   it requires read access to the data directory.
   You can specify the data directory on the command line, or use
   the environment variable <envar>PGDATA</envar>.  This utility supports the options
   <option>-V</option> and <option>--version</option>, which print the
   <application>pg_controldata</application> version and exit.  It also
   supports options <option>-?</option> and <option>--help</option>, which output the
   supported arguments.
  </para>
 </refsect1>

 <refsect1>
  <title>Environment</title>

  <variablelist>
   <varlistentry>
    <term><envar>PGDATA</envar></term>

    <listitem>
     <para>
      Default data directory location
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><envar>PG_COLOR</envar></term>
    <listitem>
     <para>
      Specifies whether to use color in diagnostic messages. Possible values
      are <literal>always</literal>, <literal>auto</literal> and
      <literal>never</literal>.
     </para>
    </listitem>
   </varlistentry>
  </variablelist>
 </refsect1>
</refentry>
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ac3c4c6e (1st chunk of `doc/src/sgml/ref/pg_controldata.sgml`)
Title: pg_controldata: Display PostgreSQL Database Cluster Control Information
Summary
The pg_controldata utility prints control information about a PostgreSQL database cluster, such as the catalog version, write-ahead logging information, and checkpoint processing details. It requires read access to the data directory and must be run by the user who initialized the cluster. The utility can be used with the -D or --pgdata options to specify the data directory, or the PGDATA environment variable can be used. It also supports options for displaying the version and help information.