[IMPALA-3588] Regression in TPC-DS Q95 due to change in join order

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Cannot Reproduce
• Affects Version/s: Impala 2.6.0
• Component/s: Frontend
• Labels: planner regression
• Assignee: Mostafa Mokhtar
• Reporter: Mostafa Mokhtar
• Created: 21/May/16 00:39
• Updated: 21/May/16 01:52
• Resolved: 21/May/16 01:26

Description

TPC-DS Q95 regressed by 33% due to flip in join order, the new join order limits where runtime filters can be pushed.

Query

with ws_wh as
(select ws1.ws_order_number --,ws1.ws_warehouse_sk wh1,ws2.ws_warehouse_sk wh2
 from web_sales ws1 left semi join web_sales ws2
 on ws1.ws_order_number = ws2.ws_order_number
 and ws1.ws_warehouse_sk <> ws2.ws_warehouse_sk)
select
   count(distinct ws_order_number) as order_count
  ,sum(ws_ext_ship_cost) as total_shipping_cost
  ,sum(ws_net_profit) as total_net_profit
from
   web_sales ws1
  ,date_dim
  ,customer_address
  ,web_site
where
    d_date between cast('2000-02-01' as timestamp) and cast('2000-02-01' as timestamp) + interval 60 days
and ws1.ws_ship_date_sk = d_date_sk
and ws1.ws_ship_addr_sk = ca_address_sk
and ca_state = 'NE'
and ws1.ws_web_site_sk = web_site_sk
and web_company_name = 'pri'
and ws1.ws_order_number in (select distinct(ws_order_number)
                            from ws_wh)
and ws1.ws_order_number in (select distinct(wr_order_number)
                            from web_returns,ws_wh
                            where wr_order_number = ws_wh.ws_order_number)
order by count(distinct ws_order_number)
limit 100