linkend="pgdata-contents-table"/>).
        If this value is specified without units, it is taken as blocks,
        that is <symbol>BLCKSZ</symbol> bytes, typically 8kB.
        The default value is <literal>16</literal>.
        This parameter can only be set at server start.
       </para>
      </listitem>
     </varlistentry>

     <varlistentry id="guc-notify-buffers" xreflabel="notify_buffers">
      <term><varname>notify_buffers</varname> (<type>integer</type>)
      <indexterm>
       <primary><varname>notify_buffers</varname> configuration parameter</primary>
      </indexterm>
      </term>
      <listitem>
       <para>
        Specifies the amount of shared memory to use to cache the contents
        of <literal>pg_notify</literal> (see
        <xref linkend="pgdata-contents-table"/>).
        If this value is specified without units, it is taken as blocks,
        that is <symbol>BLCKSZ</symbol> bytes, typically 8kB.
        The default value is <literal>16</literal>.
        This parameter can only be set at server start.
       </para>
      </listitem>
     </varlistentry>

     <varlistentry id="guc-serializable-buffers" xreflabel="serializable_buffers">
      <term><varname>serializable_buffers</varname> (<type>integer</type>)
      <indexterm>
       <primary><varname>serializable_buffers</varname> configuration parameter</primary>
      </indexterm>
      </term>
      <listitem>
       <para>
        Specifies the amount of shared memory to use to cache the contents
        of <literal>pg_serial</literal> (see
        <xref linkend="pgdata-contents-table"/>).
        If this value is specified without units, it is taken as blocks,
        that is <symbol>BLCKSZ</symbol> bytes, typically 8kB.
        The default value is <literal>32</literal>.
        This parameter can only be set at server start.
       </para>
      </listitem>
     </varlistentry>

     <varlistentry id="guc-subtransaction-buffers" xreflabel="subtransaction_buffers">
      <term><varname>subtransaction_buffers</varname> (<type>integer</type>)
      <indexterm>
       <primary><varname>subtransaction_buffers</varname> configuration parameter</primary>
      </indexterm>
      </term>
      <listitem>
       <para>
        Specifies the amount of shared memory to use to cache the contents
        of <literal>pg_subtrans</literal> (see
        <xref linkend="pgdata-contents-table"/>).
        If this value is specified without units, it is taken as blocks,
        that is <symbol>BLCKSZ</symbol> bytes, typically 8kB.
        The default value is <literal>0</literal>, which requests
        <varname>shared_buffers</varname>/512 up to 1024 blocks,
        but not fewer than 16 blocks.
        This parameter can only be set at server start.
       </para>
      </listitem>
     </varlistentry>

     <varlistentry id="guc-transaction-buffers" xreflabel="transaction_buffers">
      <term><varname>transaction_buffers</varname> (<type>integer</type>)
      <indexterm>
       <primary><varname>transaction_buffers</varname> configuration parameter</primary>
      </indexterm>
      </term>
      <listitem>
       <para>
        Specifies the amount of shared memory to use to cache the contents
        of <literal>pg_xact</literal> (see
        <xref linkend="pgdata-contents-table"/>).
        If this value is specified without units, it is taken as blocks,
        that is <symbol>BLCKSZ</symbol> bytes, typically 8kB.
        The default value is <literal>0</literal>, which requests
        <varname>shared_buffers</varname>/512 up to 1024 blocks,
        but not fewer than 16 blocks.
        This parameter can only be set at server start.
       </para>
      </listitem>
     </varlistentry>

     <varlistentry id="guc-max-stack-depth" xreflabel="max_stack_depth">
      <term><varname>max_stack_depth</varname> (<type>integer</type>)
      <indexterm>
       <primary><varname>max_stack_depth</varname> configuration parameter</primary>
      </indexterm>