text: -- Licensed to the Apache Software Foundation (ASF) under one
  -- or more contributor license agreements.  See the NOTICE file
  -- distributed with 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,
  -- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  -- See the License for the specific language governing permissions and
  -- limitations under the License.
  
  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 =1999
        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=4
    and inv2.d_moy=4+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