protected function conn_configure($dsn, $dbh)
    {
        $init_queries = array(
            "ALTER SESSION SET nls_date_format = 'YYYY-MM-DD'",
            "ALTER SESSION SET nls_timestamp_format = 'YYYY-MM-DD HH24:MI:SS'",
        );

        foreach ($init_queries as $query) {
            $stmt = oci_parse($dbh, $query);
            oci_execute($stmt);
        }
    }