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-- this work for additional information regarding copyright ownership.
-- The ASF licenses this file to You under the Apache License, Version 2.0
-- (the "License"); you may not use this file except in compliance with
-- the License.  You may obtain a copy of the License at
--
--    http://www.apache.org/licenses/LICENSE-2.0
--
-- Unless required by applicable law or agreed to in writing, software
-- distributed under the License is distributed on an "AS IS" BASIS,
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--

--q39b.sql--

 with inv as
 (select w_warehouse_name,w_warehouse_sk,i_item_sk,d_moy
        ,stdev,mean, case mean when 0 then null else stdev/mean end cov
  from(select w_warehouse_name,w_warehouse_sk,i_item_sk,d_moy
             ,stddev_samp(inv_quantity_on_hand) stdev,avg(inv_quantity_on_hand) mean
       from inventory, item, warehouse, date_dim
       where inv_item_sk = i_item_sk
         and inv_warehouse_sk = w_warehouse_sk
         and inv_date_sk = d_date_sk
         and d_year = 2001
       group by w_warehouse_name,w_warehouse_sk,i_item_sk,d_moy) foo
  where case mean when 0 then 0 else stdev/mean end > 1)
 select inv1.w_warehouse_sk,inv1.i_item_sk,inv1.d_moy,inv1.mean, inv1.cov
         ,inv2.w_warehouse_sk,inv2.i_item_sk,inv2.d_moy,inv2.mean, inv2.cov
 from inv inv1,inv inv2
 where inv1.i_item_sk = inv2.i_item_sk
   and inv1.w_warehouse_sk =  inv2.w_warehouse_sk
   and inv1.d_moy=1
   and inv2.d_moy=1+1
   and inv1.cov > 1.5
 order by inv1.w_warehouse_sk,inv1.i_item_sk,inv1.d_moy,inv1.mean,inv1.cov
         ,inv2.d_moy,inv2.mean, inv2.cov
            
