my $dbh = DBI->connect('dbi:mysql:dbname', 'user', 'pwd') or die "$DBI::errstr\n"; my (undef, $max_allowed_packet) = $dbh->selectrow_array( qq{show variables LIKE ? }, undef, "max_allowed_packet" ) ; printf "max_allowed_packet => %.2f MB\n", $max_allowed_packet / (1024*1024);