text: WITH year_total AS (
    SELECT
      c_customer_id customer_id,
      c_first_name customer_first_name,
      c_last_name customer_last_name,
      c_preferred_cust_flag customer_preferred_cust_flag,
      c_birth_country customer_birth_country,
      c_login customer_login,
      c_email_address customer_email_address,
      d_year dyear,
      sum(ss_ext_list_price - ss_ext_discount_amt) year_total,
      's' sale_type
    FROM customer, store_sales, date_dim
    WHERE c_customer_sk = ss_customer_sk
      AND ss_sold_date_sk = d_date_sk
    GROUP BY c_customer_id
      , c_first_name
      , c_last_name
      , d_year
      , c_preferred_cust_flag
      , c_birth_country
      , c_login
      , c_email_address
      , d_year
    UNION ALL
    SELECT
      c_customer_id customer_id,
      c_first_name customer_first_name,
      c_last_name customer_last_name,
      c_preferred_cust_flag customer_preferred_cust_flag,
      c_birth_country customer_birth_country,
      c_login customer_login,
      c_email_address customer_email_address,
      d_year dyear,
      sum(ws_ext_list_price - ws_ext_discount_amt) year_total,
      'w' sale_type
    FROM customer, web_sales, date_dim
    WHERE c_customer_sk = ws_bill_customer_sk
      AND ws_sold_date_sk = d_date_sk
    GROUP BY
      c_customer_id, c_first_name, c_last_name, c_preferred_cust_flag, c_birth_country,
      c_login, c_email_address, d_year)
  SELECT t_s_secyear.customer_preferred_cust_flag
  FROM year_total t_s_firstyear
    , year_total t_s_secyear
    , year_total t_w_firstyear
    , year_total t_w_secyear
  WHERE t_s_secyear.customer_id = t_s_firstyear.customer_id
    AND t_s_firstyear.customer_id = t_w_secyear.customer_id
    AND t_s_firstyear.customer_id = t_w_firstyear.customer_id
    AND t_s_firstyear.sale_type = 's'
    AND t_w_firstyear.sale_type = 'w'
    AND t_s_secyear.sale_type = 's'
    AND t_w_secyear.sale_type = 'w'
    AND t_s_firstyear.dyear = 2001
    AND t_s_secyear.dyear = 2001 + 1
    AND t_w_firstyear.dyear = 2001
    AND t_w_secyear.dyear = 2001 + 1
    AND t_s_firstyear.year_total > 0
    AND t_w_firstyear.year_total > 0
    AND CASE WHEN t_w_firstyear.year_total > 0
    THEN t_w_secyear.year_total / t_w_firstyear.year_total
        ELSE NULL END
    > CASE WHEN t_s_firstyear.year_total > 0
    THEN t_s_secyear.year_total / t_s_firstyear.year_total
      ELSE NULL END
  ORDER BY t_s_secyear.customer_preferred_cust_flag
  LIMIT 100;
  