doc/src/sgml/ref/show.sgml

   1 <!--
   2 doc/src/sgml/ref/show.sgml
   3 PostgreSQL documentation
   4 -->
   5
   6 <refentry id="sql-show">
   7  <indexterm zone="sql-show">
   8   <primary>SHOW</primary>
   9  </indexterm>
  10
  11  <refmeta>
  12   <refentrytitle>SHOW</refentrytitle>
  13   <manvolnum>7</manvolnum>
  14   <refmiscinfo>SQL - Language Statements</refmiscinfo>
  15  </refmeta>
  16
  17  <refnamediv>
  18   <refname>SHOW</refname>
  19   <refpurpose>show the value of a run-time parameter</refpurpose>
  20  </refnamediv>
  21
  22  <refsynopsisdiv>
  23 <synopsis>
  24 SHOW <replaceable class="parameter">name</replaceable>
  25 SHOW ALL
  26 </synopsis>
  27  </refsynopsisdiv>
  28
  29  <refsect1>
  30   <title>Description</title>
  31
  32   <para>
  33    <command>SHOW</command> will display the current setting of
  34    run-time parameters. These variables can be set using the
  35    <command>SET</command> statement, by editing the
  36    <filename>postgresql.conf</filename> configuration file, through
  37    the <envar>PGOPTIONS</envar> environmental variable (when using
  38    <application>libpq</application> or a <application>libpq</application>-based
  39    application), or through command-line flags when starting the
  40    <command>postgres</command> server.  See <xref
  41    linkend="runtime-config"/> for details.
  42   </para>
  43  </refsect1>
  44
  45  <refsect1>
  46   <title>Parameters</title>
  47
  48   <variablelist>
  49    <varlistentry>
  50     <term><replaceable class="parameter">name</replaceable></term>
  51     <listitem>
  52      <para>
  53       The name of a run-time parameter.  Available parameters are
  54       documented in <xref linkend="runtime-config"/> and on the <xref
  55       linkend="sql-set"/> reference page.  In
  56       addition, there are a few parameters that can be shown but not
  57       set:
  58
  59       <variablelist>
  60        <varlistentry>
  61         <term><literal>SERVER_VERSION</literal></term>
  62         <listitem>
  63          <para>
  64           Shows the server's version number.
  65          </para>
  66         </listitem>
  67        </varlistentry>
  68
  69        <varlistentry>
  70         <term><literal>SERVER_ENCODING</literal></term>
  71         <listitem>
  72          <para>
  73           Shows the server-side character set encoding.  At present,
  74           this parameter can be shown but not set, because the
  75           encoding is determined at database creation time.
  76          </para>
  77         </listitem>
  78        </varlistentry>
  79
  80        <varlistentry>
  81         <term><literal>IS_SUPERUSER</literal></term>
  82         <listitem>
  83          <para>
  84           True if the current role has superuser privileges.
  85          </para>
  86         </listitem>
  87        </varlistentry>
  88       </variablelist></para>
  89     </listitem>
  90    </varlistentry>
  91
  92    <varlistentry>
  93     <term><literal>ALL</literal></term>
  94     <listitem>
  95      <para>
  96       Show the values of all configuration parameters, with descriptions.
  97      </para>
  98     </listitem>
  99    </varlistentry>
 100   </variablelist>
 101  </refsect1>
 102
 103  <refsect1>
 104   <title>Notes</title>
 105
 106   <para>
 107    The function <function>current_setting</function> produces
 108    equivalent output; see <xref linkend="functions-admin-set"/>.
 109    Also, the
 110    <link linkend="view-pg-settings"><structname>pg_settings</structname></link>
 111    system view produces the same information.
 112
 113   </para>
 114  </refsect1>
 115
 116  <refsect1>
 117   <title>Examples</title>
 118
 119   <para>
 120    Show the current setting of the parameter <varname>DateStyle</varname>:
 121
 122 <programlisting>
 123 SHOW DateStyle;
 124  DateStyle
 125 -----------
 126  ISO, MDY
 127 (1 row)
 128 </programlisting>
 129   </para>
 130
 131   <para>
 132    Show the current setting of the parameter <varname>geqo</varname>:
 133 <programlisting>
 134 SHOW geqo;
 135  geqo
 136 ------
 137  on
 138 (1 row)
 139 </programlisting>
 140   </para>
 141
 142   <para>
 143    Show all settings:
 144 <programlisting>
 145 SHOW ALL;
 146             name         | setting |                description
 147 -------------------------+---------+-------------------------------------------------
 148  allow_system_table_mods | off     | Allows modifications of the structure of ...
 149     .
 150     .
 151     .
 152  xmloption               | content | Sets whether XML data in implicit parsing ...
 153  zero_damaged_pages      | off     | Continues processing past damaged page headers.
 154 (196 rows)
 155 </programlisting></para>
 156  </refsect1>
 157
 158  <refsect1>
 159   <title>Compatibility</title>
 160
 161   <para>
 162    The <command>SHOW</command> command is a
 163    <productname>PostgreSQL</productname> extension.
 164   </para>
 165  </refsect1>
 166
 167  <refsect1>
 168   <title>See Also</title>
 169
 170   <simplelist type="inline">
 171    <member><xref linkend="sql-set"/></member>
 172    <member><xref linkend="sql-reset"/></member>
 173   </simplelist>
 174  </refsect1>
 175
 176 </refentry>