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>LC_COLLATE</literal></term>
  82         <listitem>
  83          <para>
  84           Shows the database's locale setting for collation (text
  85           ordering).  At present, this parameter can be shown but not
  86           set, because the setting is determined at database creation
  87           time.
  88          </para>
  89         </listitem>
  90        </varlistentry>
  91
  92        <varlistentry>
  93         <term><literal>LC_CTYPE</literal></term>
  94         <listitem>
  95          <para>
  96           Shows the database's locale setting for character
  97           classification.  At present, this parameter can be shown but
  98           not set, because the setting is determined at database creation
  99           time.
 100          </para>
 101         </listitem>
 102        </varlistentry>
 103
 104        <varlistentry>
 105         <term><literal>IS_SUPERUSER</literal></term>
 106         <listitem>
 107          <para>
 108           True if the current role has superuser privileges.
 109          </para>
 110         </listitem>
 111        </varlistentry>
 112       </variablelist></para>
 113     </listitem>
 114    </varlistentry>
 115
 116    <varlistentry>
 117     <term><literal>ALL</literal></term>
 118     <listitem>
 119      <para>
 120       Show the values of all configuration parameters, with descriptions.
 121      </para>
 122     </listitem>
 123    </varlistentry>
 124   </variablelist>
 125  </refsect1>
 126
 127  <refsect1>
 128   <title>Notes</title>
 129
 130   <para>
 131    The function <function>current_setting</function> produces
 132    equivalent output; see <xref linkend="functions-admin-set"/>.
 133    Also, the
 134    <link linkend="view-pg-settings"><structname>pg_settings</structname></link>
 135    system view produces the same information.
 136
 137   </para>
 138  </refsect1>
 139
 140  <refsect1>
 141   <title>Examples</title>
 142
 143   <para>
 144    Show the current setting of the parameter <varname>DateStyle</varname>:
 145
 146 <programlisting>
 147 SHOW DateStyle;
 148  DateStyle
 149 -----------
 150  ISO, MDY
 151 (1 row)
 152 </programlisting>
 153   </para>
 154
 155   <para>
 156    Show the current setting of the parameter <varname>geqo</varname>:
 157 <programlisting>
 158 SHOW geqo;
 159  geqo
 160 ------
 161  on
 162 (1 row)
 163 </programlisting>
 164   </para>
 165
 166   <para>
 167    Show all settings:
 168 <programlisting>
 169 SHOW ALL;
 170             name         | setting |                description
 171 -------------------------+---------+-------------------------------------------------
 172  allow_system_table_mods | off     | Allows modifications of the structure of ...
 173     .
 174     .
 175     .
 176  xmloption               | content | Sets whether XML data in implicit parsing ...
 177  zero_damaged_pages      | off     | Continues processing past damaged page headers.
 178 (196 rows)
 179 </programlisting></para>
 180  </refsect1>
 181
 182  <refsect1>
 183   <title>Compatibility</title>
 184
 185   <para>
 186    The <command>SHOW</command> command is a
 187    <productname>PostgreSQL</productname> extension.
 188   </para>
 189  </refsect1>
 190
 191  <refsect1>
 192   <title>See Also</title>
 193
 194   <simplelist type="inline">
 195    <member><xref linkend="sql-set"/></member>
 196    <member><xref linkend="sql-reset"/></member>
 197   </simplelist>
 198  </refsect1>
 199
 200 </refentry>