my $sth = $dbn -> prepare("select number,id,start_dat,end_dat from SUBSCRIBERSLIST");
$sth -> execute();
$sth->bind_columns(\$number, \$id,\$start_dat,\$end_dat);

my $max_row=5000;
my $rowcache;
my %hash =();

while (my $aref = shift(@$rowcache)
|| shift ( @{$rowcache= $sth->fetchall_arrayref(undef, $max_rows)} )
)
{
        # $aref now contains only one row
        push @{$hash{$aref[0]}}, [ $aref[1],$aref[2],$aref[3] ];
};


$sth->finish();
$dbn->disconnect;