doc/src/sgml/ref/show.sgml

   1 <!--
   2 $PostgreSQL$
   3 PostgreSQL documentation
   4 -->
   5
   6 <refentry id="SQL-SHOW">
   7  <refmeta>
   8   <refentrytitle id="SQL-SHOW-TITLE">SHOW</refentrytitle>
   9   <manvolnum>7</manvolnum>
  10   <refmiscinfo>SQL - Language Statements</refmiscinfo>
  11  </refmeta>
  12
  13  <refnamediv>
  14   <refname>SHOW</refname>
  15   <refpurpose>show the value of a run-time parameter</refpurpose>
  16  </refnamediv>
  17
  18  <indexterm zone="sql-show">
  19   <primary>SHOW</primary>
  20  </indexterm>
  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</> or a <application>libpq</>-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" endterm="SQL-SET-title"> 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>
 113      </para>
 114     </listitem>
 115    </varlistentry>
 116
 117    <varlistentry>
 118     <term><literal>ALL</literal></term>
 119     <listitem>
 120      <para>
 121       Show the values of all configuration parameters, with descriptions.
 122      </para>
 123     </listitem>
 124    </varlistentry>
 125   </variablelist>
 126  </refsect1>
 127
 128  <refsect1>
 129   <title>Notes</title>
 130
 131   <para>
 132    The function <function>current_setting</function> produces
 133    equivalent output; see <xref linkend="functions-admin">.
 134    Also, the
 135    <link linkend="view-pg-settings"><structname>pg_settings</structname></link>
 136    system view produces the same information.
 137
 138   </para>
 139  </refsect1>
 140
 141  <refsect1>
 142   <title>Examples</title>
 143
 144   <para>
 145    Show the current setting of the parameter <varname>DateStyle</varname>:
 146
 147 <programlisting>
 148 SHOW DateStyle;
 149  DateStyle
 150 -----------
 151  ISO, MDY
 152 (1 row)
 153 </programlisting>
 154   </para>
 155
 156   <para>
 157    Show the current setting of the parameter <varname>geqo</varname>:
 158 <programlisting>
 159 SHOW geqo;
 160  geqo
 161 ------
 162  on
 163 (1 row)
 164 </programlisting>
 165   </para>
 166
 167   <para>
 168    Show all settings:
 169 <programlisting>
 170 SHOW ALL;
 171               name              |            setting             |                                         description
 172 --------------------------------+--------------------------------+----------------------------------------------------------------------------------------------
 173  add_missing_from               | off                            | Automatically adds missing table references to FROM clauses.
 174  allow_system_table_mods        | off                            | Allows modifications of the structure of system tables.
 175     .
 176     .
 177     .
 178  work_mem                       | 1024                           | Sets the maximum memory to be used for query workspaces.
 179  zero_damaged_pages             | off                            | Continues processing past damaged page headers.
 180 (146 rows)
 181 </programlisting>
 182   </para>
 183  </refsect1>
 184
 185  <refsect1>
 186   <title>Compatibility</title>
 187
 188   <para>
 189    The <command>SHOW</command> command is a
 190    <productname>PostgreSQL</productname> extension.
 191   </para>
 192  </refsect1>
 193
 194  <refsect1>
 195   <title>See Also</title>
 196
 197   <simplelist type="inline">
 198    <member><xref linkend="SQL-SET" endterm="SQL-SET-title"></member>
 199    <member><xref linkend="SQL-RESET" endterm="SQL-RESET-title"></member>
 200   </simplelist>
 201  </refsect1>
 202
 203 </refentry>