</para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><replaceable class="parameter">argmode</replaceable></term>

    <listitem>
     <para>
      The mode of an argument: <literal>IN</literal>, <literal>OUT</literal>,
      <literal>INOUT</literal>, or <literal>VARIADIC</literal>.
      If omitted, the default is <literal>IN</literal>.
      Note that <command>DROP FUNCTION</command> does not actually pay
      any attention to <literal>OUT</literal> arguments, since only the input
      arguments are needed to determine the function's identity.
      So it is sufficient to list the <literal>IN</literal>, <literal>INOUT</literal>,
      and <literal>VARIADIC</literal> arguments.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><replaceable class="parameter">argname</replaceable></term>

    <listitem>
     <para>
      The name of an argument.
      Note that <command>DROP FUNCTION</command> does not actually pay
      any attention to argument names, since only the argument data
      types are needed to determine the function's identity.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><replaceable class="parameter">argtype</replaceable></term>

    <listitem>
     <para>
      The data type(s) of the function's arguments (optionally
      schema-qualified), if any.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><literal>CASCADE</literal></term>
    <listitem>
     <para>
      Automatically drop objects that depend on the function (such as
      operators or triggers),
      and in turn all objects that depend on those objects
      (see <xref linkend="ddl-depend"/>).
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><literal>RESTRICT</literal></term>
    <listitem>
     <para>
      Refuse to drop the function if any objects depend on it.  This
      is the default.
     </para>
    </listitem>
   </varlistentry>
  </variablelist>
 </refsect1>

 <refsect1 id="sql-dropfunction-examples">
  <title>Examples</title>

  <para>
   This command removes the square root function:

<programlisting>
DROP FUNCTION sqrt(integer);
</programlisting></para>

  <para>
   Drop multiple functions in one command:
<programlisting>
DROP FUNCTION sqrt(integer), sqrt(bigint);
</programlisting></para>

  <para>
   If the function name is unique in its schema, it can be referred to without
   an argument list:
<programlisting>
DROP FUNCTION update_employee_salaries;
</programlisting>
   Note that this is different from
<programlisting>
DROP FUNCTION update_employee_salaries();
</programlisting>
   which refers to a function with zero arguments, whereas the first variant
   can refer to a function with any number of arguments, including zero, as
   long as the name is unique.
  </para>
 </refsect1>

 <refsect1 id="sql-dropfunction-compatibility">
  <title>Compatibility</title>

  <para>
   This command conforms to the SQL standard, with
   these <productname>PostgreSQL</productname> extensions:
   <itemizedlist>
    <listitem>
     <para>The standard only allows one function to be dropped per command.</para>
    </listitem>
    <listitem>
     <para>The <literal>IF EXISTS</literal> option</para>
    </listitem>
    <listitem>
     <para>The ability to specify argument modes and names</para>
    </listitem>
   </itemizedlist></para>
 </refsect1>

 <refsect1>
  <title>See Also</title>

  <simplelist type="inline">
   <member><xref linkend="sql-createfunction"/></member>
   <member><xref linkend="sql-alterfunction"/></member>
   <member><xref linkend="sql-dropprocedure"/></member>
   <member><xref linkend="sql-droproutine"/></member>
  </simplelist>
 </refsect1>

</refentry>