<literal>ON</literal> and <literal>OFF</literal> are allowed as
      described in <xref linkend="config-setting"/>.) The default is
      <literal>ON</literal>.
    </para>

    <note>
     <para>
      Turning <literal>deduplicate_items</literal> off via
      <command>ALTER INDEX</command> prevents future insertions from
      triggering deduplication, but does not in itself make existing
      posting list tuples use the standard tuple representation.
     </para>
    </note>
    </listitem>
   </varlistentry>
   </variablelist>

   <para>
    GiST indexes additionally accept this parameter:
   </para>

   <variablelist>
   <varlistentry id="index-reloption-buffering" xreflabel="buffering">
    <term><literal>buffering</literal> (<type>enum</type>)
     <indexterm>
      <primary><varname>buffering</varname> storage parameter</primary>
     </indexterm>
    </term>
    <listitem>
    <para>
     Controls whether the buffered build technique described in
     <xref linkend="gist-buffering-build"/> is used to build the index. With
     <literal>OFF</literal> buffering is disabled, with <literal>ON</literal>
     it is enabled, and with <literal>AUTO</literal> it is initially disabled,
     but is turned on on-the-fly once the index size reaches
     <xref linkend="guc-effective-cache-size"/>.  The default
     is <literal>AUTO</literal>.
     Note that if sorted build is possible, it will be used instead of
     buffered build unless <literal>buffering=ON</literal> is specified.
    </para>
    </listitem>
   </varlistentry>
   </variablelist>

   <para>
    GIN indexes accept these parameters:
   </para>

   <variablelist>
   <varlistentry id="index-reloption-fastupdate" xreflabel="fastupdate">
    <term><literal>fastupdate</literal> (<type>boolean</type>)
     <indexterm>
      <primary><varname>fastupdate</varname> storage parameter</primary>
     </indexterm>
    </term>
    <listitem>
    <para>
     Controls usage of the fast update technique described in
     <xref linkend="gin-fast-update"/>.
     <literal>ON</literal> enables fast update, <literal>OFF</literal> disables it.
     The default is <literal>ON</literal>.
    </para>

    <note>
     <para>
      Turning <literal>fastupdate</literal> off via <command>ALTER INDEX</command> prevents
      future insertions from going into the list of pending index entries,
      but does not in itself flush existing entries.  You might want to
      <command>VACUUM</command> the table or call
      the <function>gin_clean_pending_list</function>
      function afterward to ensure the pending list is emptied.
     </para>
    </note>
    </listitem>
   </varlistentry>
   </variablelist>

   <variablelist>
   <varlistentry id="index-reloption-gin-pending-list-limit" xreflabel="gin_pending_list_limit">
    <term><literal>gin_pending_list_limit</literal> (<type>integer</type>)
     <indexterm>
      <primary><varname>gin_pending_list_limit</varname></primary>
      <secondary>storage parameter</secondary>
     </indexterm>
    </term>
    <listitem>
    <para>
     Overrides the global setting of
     <xref linkend="guc-gin-pending-list-limit"/> for this index.
     This value is specified in kilobytes.
    </para>
    </listitem>
   </varlistentry>
   </variablelist>

   <para>
    <acronym>BRIN</acronym> indexes accept these parameters:
   </para>

   <variablelist>
   <varlistentry id="index-reloption-pages-per-range" xreflabel="pages_per_range">
    <term><literal>pages_per_range</literal> (<type>integer</type>)
     <indexterm>
      <primary><varname>pages_per_range</varname> storage parameter</primary>
     </indexterm>
    </term>
    <listitem>
    <para>
     Defines the number of table blocks that make up one block range for
     each entry of a <acronym>BRIN</acronym> index (see <xref linkend="brin-intro"/>
     for more details).  The default is <literal>128</literal>.
    </para>
    </listitem>
   </varlistentry>

   <varlistentry id="index-reloption-autosummarize"