use strict;
use warnings;

my $lastrecord = $rdb->last_record; # Call this only once

my $i = 0; # Starting record number ?
my $counter = 0;

while (my ($recordnumber, $X, $Y, $comments) = 
                 $rdb->get_record($i,"X", "Y");
   $i = $recordnumber;
   last if $i > $lastrecord;
   
   if ($X < 20){
      $wdb->set_record($i,$X,$Y,"Good");
   }elsif ($Y > 5){
      if (++$counter > 10){
           $wdb->set_record($i,$X,$Y,"Worse");
      }else{
            $wdb->set_record($i,$X,$Y,"bad");
      }
   }
}