$i=0;
while (my $ref = $query->fetchrow_hashref()) {
   print "url: $ref->{url}\n";
   my $ff = File::Fetch->new(uri=>$ref->{url});
   my $where = $ff->fetch( to => '/data/documents/');
      my $error= $ff->error();

   rename ("C:/data/documents/document.pdf","C:/data/documents/document$i.pdf");
 ($i++);
   }