all, you could also write a transform function that always
   errors out.)
  </para>

  <para>
   To be able to create a transform, you must own and
   have <literal>USAGE</literal> privilege on the type, have
   <literal>USAGE</literal> privilege on the language, and own and
   have <literal>EXECUTE</literal> privilege on the from-SQL and to-SQL
   functions, if specified.
  </para>
 </refsect1>

 <refsect1>
  <title>Parameters</title>

   <variablelist>
    <varlistentry>
     <term><replaceable>type_name</replaceable></term>

     <listitem>
      <para>
       The name of the data type of the transform.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry>
     <term><replaceable>lang_name</replaceable></term>

     <listitem>
      <para>
       The name of the language of the transform.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry>
     <term><literal><replaceable>from_sql_function_name</replaceable>[(<replaceable>argument_type</replaceable> [, ...])]</literal></term>

     <listitem>
      <para>
       The name of the function for converting the type from the SQL
       environment to the language.  It must take one argument of
       type <type>internal</type> and return type <type>internal</type>.  The
       actual argument will be of the type for the transform, and the function
       should be coded as if it were.  (But it is not allowed to declare an
       SQL-level function returning <type>internal</type> without at
       least one argument of type <type>internal</type>.)  The actual return
       value will be something specific to the language implementation.
       If no argument list is specified, the function name must be unique in
       its schema.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry>
     <term><literal><replaceable>to_sql_function_name</replaceable>[(<replaceable>argument_type</replaceable> [, ...])]</literal></term>

     <listitem>
      <para>
       The name of the function for converting the type from the language to
       the SQL environment.  It must take one argument of type
       <type>internal</type> and return the type that is the type for the
       transform.  The actual argument value will be something specific