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$Header: /cvsroot/pgsql/doc/src/sgml/ref/show.sgml,v 1.14 2001/09/14 08:47:00 ishii Exp $
Postgres documentation
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<refentry id="SQL-SHOW">
 <refmeta>
  <refentrytitle id="SQL-SHOW-TITLE">SHOW</refentrytitle>
  <refmiscinfo>SQL - Language Statements</refmiscinfo>
 </refmeta>
 <refnamediv>
  <refname>SHOW</refname>
  <refpurpose>show the value of a run-time parameter</refpurpose>
 </refnamediv>
 <refsynopsisdiv>
  <synopsis>
SHOW <replaceable class="PARAMETER">name</replaceable>
  </synopsis>
  <synopsis>
SHOW ALL
  </synopsis>

  <refsect2 id="R2-SQL-SHOW-1">
   <title>Inputs</title>

   <para>
    <variablelist>
     <varlistentry>
      <term><replaceable class="PARAMETER">name</replaceable></term>
      <listitem>
       <para>
        The name of a run-time parameter. See
	<xref linkend="sql-set" endterm="sql-set-title">
        for a list.
       </para>
      </listitem>
     </varlistentry>
     <varlistentry>
      <term>ALL</term>
      <listitem>
       <para>
        Show all current session parameters.
       </para>
      </listitem>
     </varlistentry>
    </variablelist>
   </para>
  </refsect2>

 </refsynopsisdiv>

 <refsect1 id="R1-SQL-SHOW-1">
  <title>Description</title>
  <para>
   <command>SHOW</command> will display the current setting of a
   run-time parameter. These variables can be set using the
   <command>SET</command> statement or are determined at server start.
  </para>
 </refsect1>

 <refsect1>
  <title>Diagnostics</title>

   <para>
    <variablelist>
     <varlistentry>
      <term><computeroutput>ERROR:  not a valid option name: <replaceable>name</replaceable></computeroutput></term>
      <listitem>
       <para>
	Message returned if <replaceable>variable</replaceable> does
	not stand for an existing parameter.
       </para>
      </listitem>
     </varlistentry>

     <varlistentry>
      <term><computeroutput>ERROR:  permission denied</computeroutput></term>
      <listitem>
       <para>
        You must be a superuser to be allowed to see certain settings.
       </para>
      </listitem>
     </varlistentry>

     <varlistentry>
      <term><computeroutput>NOTICE:  Time zone is unknown</computeroutput></term>
      <listitem>
       <para>
	If the <envar>TZ</envar> or <envar>PGTZ</envar> environment
	variable is not set.
       </para>
      </listitem>
     </varlistentry>
    </variablelist>
   </para>
 </refsect1>

 <refsect1 id="R1-SQL-SHOW-2">
  <title>Examples</title>
  <para>
   Show the current <literal>DateStyle</literal> setting:

<screen>
SHOW DateStyle;
NOTICE:  DateStyle is ISO with US (NonEuropean) conventions
</screen>
  </para>

  <para>
   Show the current genetic optimizer (<literal>geqo</literal>) setting:
<screen>
SHOW GEQO;
NOTICE:  geqo is on
</screen>
  </para>
 </refsect1>

 <refsect1 id="R1-SQL-SHOW-3">
  <title>Compatibility</title>

  <para>
   The <command>SHOW</command> command is a
   <productname>Postgres</productname> extension.
  </para>
 </refsect1>
</refentry>

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