set search_path to tpcds;
with v1 as(
 select i_category, i_brand,
        cc_name,
        d_year, d_moy,
        sum(cs_sales_price) sum_sales,
        avg(sum(cs_sales_price)) over
          (partition by i_category, i_brand,
                     cc_name, d_year)
          avg_monthly_sales,
        rank() over
          (partition by i_category, i_brand,
                     cc_name
           order by d_year, d_moy) rn
 from item, catalog_sales, date_dim, call_center
 where cs_item_sk = i_item_sk and
       cs_sold_date_sk = d_date_sk and
       cc_call_center_sk= cs_call_center_sk and
       (
         d_year = 1999 or
         ( d_year = 1999-1 and d_moy =12) or
         ( d_year = 1999+1 and d_moy =1)
       )
 group by i_category, i_brand,
          cc_name , d_year, d_moy),
 v2 as(
 select v1.i_brand
        ,v1.d_year
        ,v1.avg_monthly_sales
        ,v1.sum_sales, v1_lag.sum_sales psum, v1_lead.sum_sales nsum
 from v1, v1 v1_lag, v1 v1_lead
 where v1.i_category = v1_lag.i_category and
       v1.i_category = v1_lead.i_category and
       v1.i_brand = v1_lag.i_brand and
       v1.i_brand = v1_lead.i_brand and
       v1. cc_name = v1_lag. cc_name and
       v1. cc_name = v1_lead. cc_name and
       v1.rn = v1_lag.rn + 1 and
       v1.rn = v1_lead.rn - 1)
  select  *
 from v2
 where  d_year = 1999 and
        avg_monthly_sales > 0 and
        case when avg_monthly_sales > 0 then abs(sum_sales - avg_monthly_sales) / avg_monthly_sales else null end > 0.1
 order by sum_sales - avg_monthly_sales, 3
 limit 100;
