unshift @fields, qw(hostname host_id);
my $insert = "INSERT IGNORE INTO $thisTable (" . join(", ", @fields) . ") VALUES (" . join(",", ('?') x @fields) . ")";

while (my @row = $dbq->fetchrow_array) {
  my $this_insert = [ $site_hostname, $site_id, @row ];
  push @central_insert, $this_insert;
}

##</code><code>##

my $sth = $dbh->prepare($insert);
$sth->execute(@$_) for @central_insert;