my %data;
while ( more data ) {
    my ($ip,$domain,@times) = readNextChunkOfData();

    $data{$domain}{'ip'}= $ip;
    $data{$domain}{'seconds'} = \@times;

    # the next line isn't necessary, but could be convenient 
    # IF YOU KNOW YOUR IP/DOMAIN NAME PAIRS ARE UNIQUE.
    # for doing domain-from-ip lookups.
    $data{$ip}{'domain'} = $domain;
}