Error message db_unsuported_feature vs db_unsupported_function

[eluser]Seppo[/eluser]
Is there any difference between them?

$lang['db_unsupported_function'] = 'This feature is not available for the database you are using.';
$lang['db_unsuported_feature'] = 'Unsupported feature of the database platform you are using.';

I think both are used for the same... wouldn't be better to mix them in one?