text: 
  select i_item_id
        ,i_item_desc 
        ,i_category 
        ,i_class 
        ,i_current_price
        ,sum(ss_ext_sales_price) as itemrevenue 
        ,sum(ss_ext_sales_price)*100/sum(sum(ss_ext_sales_price)) over
            (partition by i_class) as revenueratio
  from	
  	store_sales
      	,item 
      	,date_dim
  where 
  	ss_item_sk = i_item_sk 
    	and i_category in ('Jewelry', 'Sports', 'Books')
    	and ss_sold_date_sk = d_date_sk
  	and d_date between cast('2001-01-12' as date) 
  				and (cast('2001-01-12' as date) + 30 days)
  group by 
  	i_item_id
          ,i_item_desc 
          ,i_category
          ,i_class
          ,i_current_price
  order by 
  	i_category
          ,i_class
          ,i_item_id
          ,i_item_desc
          ,revenueratio;
  
  
  