my $dbh = DBI->connect("dbi:Oracle:$dbname", $user, $passwd,
        {
            AutoCommit => 0,
            RaiseError => 1,
            RowCacheSize => 10000,
            ora_array_chunk_size => 100000,
            #ora_check_sql => 0,
            #ora_verbose => 0xff,
            #ora_oci_success_warn => 1,
        }
);