# This should not have the '$dbh->' at the beginning, but the real issue is
# $cluster here is a scalar, but
foreach my $cluster (@clusters) {
# here, they are being treated as arrays (if they were interpolated as written.
# $dbh->do ("INSERT INTO $table (start, end) VALUES (cluster[0], cluster[1]);");
# a better approach, if your DBI module supports placeholders:
$dbh->do ("INSERT INTO $table (start, end) VALUES (?,?);", @{$cluster})
# or even: $dbh->do ("INSERT INTO $table (start, end) VALUES (?,?);", $cluster->[0], $cluster->[1])
}

##</code><code>##

@_=qw;
Just another Perl hacker,;
;$_=q=print
"@_"= and eval;