$db = tie @tie, ...., $DB_RECNO;

$db->filter_fetch_value( sub { $_ = eval } );

while($tie[0]->timestamp < time - 3600) {
  shift @tie;
}

##</code><code>##

foreach $rec (@tie) {
  my $x = $rec;
  print "timestamp1: ", $rec->timestamp, "\n";
  print "timestamp2: ", $x->timestamp, "\n";
}

##</code><code>##

foreach $rec (@tie) {

  my $x = $rec;

  print "rec: $rec, x: $x\n";
}

##</code><code>##

$x = $rec;
print $x == $rec ? "match\n" : "differ\n"; # always returns 'differ'