fetch all records from table dbi

I am expecting to fetch all the below records from table through perl. Currently, i am getting a out of memory issue. Any other best alternative way to read all the records.
Query to fetch all records from the table.
select cpu_id, system, generation, vendor, item, week_first_moved, week_last_moved from us_item_tbl
Rows :5812750
Fetching all records through below code and getting out of memory:

sub sane {
my $self = shift;
my %lookup;
my $dbh = DBI->connect ('dbi:Oracle:usbmfs', 'US', 'states', {AutoCommit => 0, RaiseError => 1});
my $sth = $dbh->prepare (qq{ select cpu_id, system, generation, vendor, item, week_first_moved, week_last_moved from us_item_tbl});
$sth->execute();
my $rows = @{$dbh->selectall_arrayref('select upc_id, system, generation, vendor, item, week_first_moved, eek_last_moved from uk_item_tbl')};
foreach my $row (@$rows) {
my($cpu, sys, $gen, $vend, $item, $wad, $wlm) =@$rows;
my $ean = sprintf "%02s%05s%05s", $sys, $vend, $item;
$cpu = sprintf "%014s", $cpu;
$lookup{$nae}{$cpu} = [$wad, $wlm];
}

}